Hi all,

I recently bought a 1997 ford ranger with an oil leak and I am trying to diagnose and resolve this issue. I initially thought this was due to a rear main seal from my searching on the forum as this seemed to be a common issue for oil pooling at the bellhouse inspection hole. I went ahead and dropped the transmission and replaced the rear main seal at the weekend with a sleeved one. I also replaced the oil pan gasket while I was there (what a job that was).

I started it up and the same leak persisted. As I had also done an oil change the leak was much bigger as the fresher oil seemed to flow better. I then found its actually coming from above the bell house and running down, around the starter and pooling at the bottom of the bell house. I can't see exactly where its coming from but I have tried to find a picture of the back of the engine and put an arrow where I see it coming from and running to.

I took the valve covers off yesterday, re-torqued the head bolts and re-sealed the gaskets with some rtv. Put it back together again and found that the leak was just as bad. Since then I have done some more searching and it would appear its either one of two things; A) Lower intake manifold gasket or B) head gasket. I did do a compression test on the cylinders and it came back fine but I understand it could still leak oil and pass a compression test.

Obviously the easier fix would be the lower intake manifold gasket but I had some questions:

1. I have read that I should be losing coolant if it is the lower intake gasket but I am only losing oil. Is that plausible?
2. I can buy a lower intake manifold gasket for around $90 (few pro) and the head gasket set is not much more and includes the lower intake gasket. Can I buy the head gasket set and not use the head gaskets and if the first attempt doest fix it and I do need to pull the head can I re-use the Lower intake gasket etc? Or is it a one time use application type deal?
3. Is there anything other than a Lower intake or head gasket that could be causing that leak? I don't see any sensors etc.

Any help would be greatly appreciated. I am trying my best to learn here but not sure if I am on the right tracks?

I have attached a video of what I can capture of the leak also:

 

You should NOT have re-torqued head bolts, they are TTY(torque to yield), they do not have a final ft/lb torque rating, they are "stretch bolts".

Rear Cam shaft core plug could leak but you should have seen oil on the back of the block with flywheel off.

Top rear of the block has the Cam sensor and synchronizer, seen here: http://fortuneelevatorconsultants.co...ewflywheel.jpg

Black cap center of picture, but wouldn't expect that much oil from bad seal there

Lower Intake manifold at the rear doesn't have a gasket, the gasket "kit" will come with a tube of RTV that you put on front and rear rails of block which seals that gap when intake is lowered into place, the intake gasket is for the water passages and air ports in the heads

Oil under the lower intake would just be from splashed oil from cam and lifters, so gravity leak, but if there is an open gap then I guess you could get a good flow out of it
Picture here of intake gasket in place: http://i37.tinypic.com/2gxia1t.jpg
You can see cam sensor at the back, and you can see the rails at the front and back where RTV goes, and most gaskets have the splash shield at the front and back that would limit and oil "hitting" the rear or front seals
Lower intake has very low torque spec, like 14ft/lb so did have issues with loosing bolts, which usually caused vacuum leaks, not oil leaks

Only oil passage I know of in the head is in the center, look here: http://www.enginepartstore.com/image...ucts/v406b.png

You can see the center rocker assembly mounting bolt hole has the oil feed for the assembly, that's the only Pressure passage in the head
There are oil drains in the heads at the ends, but also a gravity passage, no pressure

 

Hi Ron,

Thank you for your continued replies to my questions.

Ok, lesson learned, I read somewhere that they can come loose so re-torquing them can solve the issue. They didn't actually move anyway, the torque wrench just clicked on every one.

I have circled some of the parts in the image and was wondering if I can just confirm a couple of things:

1. The red square - Is this is the Cam sensor and Synchronizer you mentioned? I just want to confirm from a different angle
2. The Yellow Highlights - Is this the RTV that you mention? They look more like formed gaskets or are these the rails you mention where I apply the RTV on top?

When I bought the car they seller advised they had redone the passenger head because it had a stuck valve. So I am wondering if they perhaps didn't know/forgot to put the RTV seal in to seal the ends up. A few other symptoms I get is that the car struggle to start cold, it will start, die after a few seconds unless I keep the revs up, but if I start it up a second time its absolutely fine. I have also been getting codes about it being too lean in the bank etc.

When I had the valve covers off, I seen two braided hoses which I assumed were high pressure oil lines. There was no residue oil around them so I assume they are good.

I would like to tackle this job next week and take the lower intake off and check the rails and RTV/Cam Sensor etc. Can I take it apart and just reuse the gaskets that are there? Is there anything I will need to replace by opening it up for a look?

Again, Thank you for taking the time to explain everything. I am very keen to learn and do this myself. I bought an older truck to learn how to fix these things so I appreciate you taking the time!

Thanks
Scott

 

On my 3 litre, the oil sender is in that area (maybe not the same for a 4 litre)
Is the sender leaking _damaged _ defective _ loose ???

That's a lot of oil pouring out the back, none of the things mentioned here would cause that much oil to leak out.
The engine seal and the cam plug at the back of the cam, as Ron mentioned would, but that's been gone over.
Find the leak, more time and money is wasted in desperate attempts to find the problem by blindly pulling everything apart and removing major engine components.
If you pull the lower intake manifold, don't reuse the old gasket.
Don't pull the heads, that's not where the oil is coming from.

The Fel-Pro set is only 24 bucks at Rock Auto

http://www.rockauto.com/en/moreinfo....=1138160&jsn=9

http://www.rockauto.com/en/catalog/f...ld+gasket,5424

 

Hi Jeff,

Thanks for the reply, My plan was to purchase the gasket set from rock auto.com:

MAHLE ORIGINAL/VICTOR REINZ MIS19316 Molded Rubber Info
Master Set; Contains Intake and Valve Cover Gaskets Plus All Miscellaneous Gaskets And Seals Needed for Intake Installation. Contains Metal Carrier Intake Manifold Gasket

I was going to then take off the valve covers off, intake manifold and replace the gasket/check the cam sensor for oil etc. The hard part I have is its impossible to see where the oil is coming from without taking the intake manifold etc off, but then I can't run the engine to see where its coming from.

I was of the understanding that the lower intake manifold gaskets did not have ends on them, it was just a case of using RTV to then lower the intake manifold onto? The previous owner just rebuilt the passenger head because of a sticking valve. So I wonder if he forgot/didnt know to seal the ends with RTV.

Thanks
Scott

 

Yes, you're right, there are no end seals on the lower intake (just checked) (my 3 liter has them so just assumed).

At any rate, where the RTV sealant goes, that area isn't under any pressure, I just can't see that much oil spewing out of that area, even with no sealant in place.
At this point, I'm going to say that's not where the leak is.

Yes, the 4 litres are a "Bitch" can't see anything back there.
If it was me I would shampoo the engine is best as possible.
Use an engine shampoo/degreaser that you can use a garden to wash it off with.
Have a friend fire it up while watching through a mirror.

A leak that large should be easily seen with a clean engine.

Also, about Gaskets, I recommend Fel-Pro, never used anything else.
The owner of my machine shop that I've known for 30 years says to use nothing else.
He builds race engines and he's machined a number of engines for me and does top notch work _lots of credibility and experience.

If you do take the manifold off, then you will have easy access to the cam sensor.

You then can easily remove the synchronizer itself to inspect the "O" ring.
Make a note where the tooth is on the synchronizer and mark it before pulling it out _ don't turn the engine over so you can get it back in the exact same position.

With the synchronizer out, you can get your self a long 1/4 inch extension, and the correct size socket (I can check later to find the right size) and turn the oil pump with a drill (run the drill clock-wise)

Use a some duct tape to secure the socket to the extension, you don't want the socket dropping down into the synchronizer hole.

With oil pumping you should see clearly where the leak is.
Even more so, if the engine is clean.

 

There are no "Oil Lines" on an engine unless it has a remote mounted oil filter or turbo charger.
The braided lines are fuel lines.

After lower intake is off, if rear area is leaking then you will see it
You do need a new intake gasket set


Yes, you could run the oil pump that way, with a drill, but you could also just crank the engine over, with cam sensor/synchro in place, pull Fuel Pump Relay so gas doesn't squirt out of disconnected fuel line
And I would assume fan belt would be off at this point so no water pump, lol

Put rags down across exhaust manifolds, oil will run off the edges of the head without valve covers in place

 

Thanks for the advice, I have looked up a fel-pro kit - MS98005T and it looks like its got less parts than the Mahle one. Like extra o-rings etc. I used Fel-Pro for the oil gasket and was impressed with the quality but worried its not a complete set.

I figure Its either got to be the Head (seems unlikely), the Intake Manifold Gasket of the Cam Sync sensor O Ring. So I figured I would take the intake manifold off and get better access to the Cam Sync Sensor so I can mark it better before taking it out. I would replace the O ring and the gasket and if that doesn't fix it then it would have to be the head. Or is that flawed logic?

I bought foamy engine degreaser but I am nervous about spraying the garden hose down the back of the engine!

Ok, fuel lines make a lot of sense! I just seen them and remembered having seen them.

I guess the easiest way will be to take the intake manifold off so I can get access to the area anyway. It will be a job I tackle next week now, I just need to order a gasket set up.

 

Hi All,

I was hoping for some further advice here. I found the source of my leak, it appears when the last owner rebuilt the passenger head he didn't put RTV into ends. When I took the lower intake manifold off there was no resistance and no RTV where I expected it to be.

The concern I have is there is a lot of build up around the valves etc as detailed in the pics below. What is the best way to clean this? Do I just jam the holes with paper towels to stop it falling inside and clean it with engine degreaser or carb cleaner?

I am going to replace the o-ring on the crank sensor while I have the intake manifold out just incase as it would be near on impossible to change it at a later date without taking the manifold off etc again (in my novice opinion of course!). From what I have read I just take the sensor cap off, mark it with a sharpie to keep its position, pull it out and then re-align it to insert it again.

Any advice would be greatly appreciated!

Thanks
Scott

 

Its the Cam sensor

Yes mark it and replace it in same position, DO NOT turn the engine while cam synchro is out or mark will be meaningless

A lot of build up in the intake ports, I would clean those out for sure, almost looks like oil vapor was being pulled in so bad seal on intake gasket
Put a towel down in the valley and use tooth brush size wire brush to clean up the ports.
If you haven't drained the oil yet after you are done cleaning gasket surfaces and ports dump some 20w oil around the valley to wash any debris down to the pan then drain the oil
If you have already drained the oil then take out drain plug again put catch pan down and do the same but use more oil

When doing any engine work on the top end leave oil in until you are done cleaning, then drain it

 

thanks for the quick reply as always! It turns out the cam sensor wouldn't go back in very easily and I bent part of it so I'm just going to buy a replacement. I'm annoyed at myself as I took the time to mark it etc.

i understand I need to find TDC on piston 1 so I'm going to buy a piston stop tool. For the purposes of installing the new cam sync does it need to be tdc on the compression cycle ?

ive spent a few hours cleaning it up and will use the new oil trick. Do I want to change the oil before I crank it over or crank it a few times to flush things then change it?

thanks
scott

 

So just an update. I applied he rtv, put it all back together again and it runs so much better. It used to start up, cut out and then you had to start it a second time. But it always runs first time.

The leak has reduced substantially but it's still leaking. I get a drop of oil every 10 mins or so now. I really don't know what it can be now. It looks like the same area as it's running down over the transmission.

Im pretty deflated as I spent the whole day working on it and taking my time to do it all carefully. It's drivable now at least but I was really hoping that would be the end of my oil leaks.

Does anyone rate the uv dye for oil? As it's clean oil it's pretty hard to trace where it's coming from as it's almost see through now. I was thinking of putting the uv die in and trying to trace it that way now.

Any advice would be appreciated as always.

 

Don't think there would be a "bad" UV dye, I use Tracerline but hard to get a small bottle of it.

You only need 1/2 ounce.

Whatever dye you use, mix it with 1/2 a bottle of oil and pour that into the engine, don't put dye directly into the filler, or most will stay at the top of engine.

You can mix it with 1/4 bottle of oil and then use small funnel to pour it down dipstick tube so it goes directly into oil pan.

UV Flash lights work fine
Put a little dye on something then use the UV light so you know what to look for :)

 

great, do I need to flush the oil after this or can the dye sit in there until the next oil change?

thanks
scott

 

The Dye is inert, so can stay in any fluid for the life of that fluid with no effect

 

Thanks for the continued replies! The forum has been a huge resource for a newbie like myself trying to navigate the issues going on with my project.

So I bought a nice dye kit from Amazon that worked great. Within a few minutes I had located the leak.... thats the good news! The Bad news is that its coming from the joint between the head and the block so it looks like it needs a new head gasket. I have never tackled a project of this scale on a car before and although I bought this truck as a project I am a bit overwhelmed at the amount of work to get it running right. So I had some questions if possible:

1. I have a friend who was a mechanic in his younger days (admittedly on BMW's) who has said that if I can get the head off myself, get it machined etc and ready to go back on he will help me put it back on with the timing etc. I was planning on following the Haynes manual for getting the head off. Labelling everything as it comes off and putting screws into separate tubs labeled also. Is there anything I need to position/set before taking it apart?

2. I hear of people machining the head etc, as I understand it, this is just to get it flat again if it is warped. I was hoping to find a shop that would put new valves etc on it for me. Is it better to get an existing head machined or buy a new one? I see people recommend sites that send a new head and you just return your core.

3. Im planning on replacing the push rods also, When I have watched youtube videos I have seen people label the order they came out for wear reasons. I assume if I am replacing with new ones then I don't need to mark any order for taking them out?

4. Is it worth me replacing the timing chain while I have it all off?

5. When I bought the truck the previous owner had just rebuilt the passenger head because it had a sticky valve. On the basis that they forgot to put RTV on the rails I am questioning their attention to detail. Is it worth me taking the passenger head off also getting the machine shop to inspect it? It has no issues at the moment but I would hate to put it all back together and find a few months down the line they had cut corners I can't see.

As always, I apologize for all my questions, especially the noob ones but I am really trying to learn here and not just take it to a garage. As always any help/advice would be greatly appreciated.

Thanks
Scott

 

Too bad on that oil leak location, surprises me though, not at all common.

You have an OHV(over head valve) engine so cam timing won't be disturbed by removing the heads, Cam sensor will need to be timed, although you really do not have to remove that to redo the heads.

Yes, you will want to do BOTH heads, it will only cost what ever machine shop charges to clean, test and surface each head, so maybe $75 more

You will need to buy a head gasket set, and head bolts
Gasket set will come with 12 new valve stem seals, give those to machine shop and they will usually install them for free(included in price), or only a few $ more

Head bolts are TTY(stretch bolts), so should not be reused
They come is sets of 16, 8 bolts per head, so you have to buy 16 even if you do 1 head

Exhaust manifold bolts can be a B I T C H, they rust in place.
So before getting started try to loosen each one, without STRIPPING the head of the bolt, lol.
If all 6 on each side can be loosened then all is well
If some are not cooperating then check if the 2 nuts(some have 3 nuts/studs) on each header pipe can be removed, if so then exhaust manifold can be pulled off with the head, which makes rusted bolt extraction easier.

In my younger days I spent many many hours on one or two exhaust bolts, with trips to parts stores to get various extractor tools and then replacement bolts/nuts.
And it holds up everything.

So I now test the exhaust bolts FIRST, lol.
If there is a problem, and vehicle runs, I take it to local exhaust shop and tell them what I am doing, heads, and they will remove all the bolts and nuts then replace any that need it and then snug it all back up, "snug" being the key word there
I think the most I have ever paid was $80 for a very old and rusty V8, and pretty much every bolt and nut was replaced, lol.
They know how to do it(remove rusted exhaust bolts) and have ALL the tools needed, and have replacement parts on hand.

You have already removed lower intake, so more than 1/2 way there in that adventure
Loosen the rocker assembly on each head and remove, engine doesn't have to be in a specific position for this

I get a piece of cardboard and punch 12 holes in it with screwdriver
Then label holes, 1-3 top and 4-6 top
Then remove push rods one at a time in order from 1 to 3 then 4 to 6 and put them in the holes
This is not super important, but each push rod end and its rocker will have matched wear pattern, so.............best to keep them matched

If you want to take out the lifters after heads are off I use an egg carton, labelled as above
Lifters HAVE TO go back in before heads go on as a few can't be put in with heads on

Once heads are off see if you can find the leak, I am curious

Cleaned the block surface and piston tops, yes you can rotate the engine, it won't disturb timing, put rag/towel down in the valley to try to keep debris out.

You need a torque wrench for re-assembly

AC lines can be worked around so don't need to be disconnected

There is a Ground strap on the back of the Drivers head to firewall, make SURE that gets hooked back up, its the main ground for cab electrics

 

Since only coolant is passed from the block to the head, oil leaking from the head gasket area makes no sense _ Ron know this too.

Are you sure it only appears that the oil is leaking from the gasket, perhaps it's coming from a section of the lower intake manifold and running along the head gasket area making you think that the head gasket is leaking ?

When the head(s) are removed, you'll find out then for sure I guess, but it's just a very odd thing to have happen.

 

Ron, As always thanks for your prompt, comprehensive reply. I don't think I would have tackled the job without this forum. The last 24 hours have been a great success and I have both heads off the car!!! :)

If I am honest I was just going to leave the second head as I called the previous owner and they advised me they replaced all valves, had it machined etc etc. But when I was working on the engine I seen they had reused the existing head bolts so I had concerns they may have cut corners elsewhere. So I took it off and will take it to get checked. As the passenger side has new valves on it (they still look shiny) are the shop able to change the valve stem seals on that one also or does that involve taking the valves out again?

I should have probably waited to take the heads off until my items arrived but I wanted to make sure I could get them off before spending the money on the parts. I watched some youtube videos and a some were advising that I should coat the piston liners with oil to prevent them from rusting while the heads are off. Is there any other maintenance I should be doing as its likely going to be over a week until the parts arrive and get the heads to the machine shop. Should I be cranking it over by hand every day or so to help prevent it rusting?

Yes I learnt first hand how tough those exhaust bolts can be. Unfortunately I was already taking things apart before I seen your suggestion on taking it to an exhaust shop. I got the passenger side manifold off with no issues but the drivers side is proving tougher. I ended up taking it out with the manifold attached to the head but can't get the final nut off. I have sprayed some PB blaster and will let it sit for a few hours and try tackling it again.

I may have done this in the wrong order, I just took the 3 bolts out the the lifters and then pulled each of the push rods out. They all look pretty straight but is it worth replacing them while they are out? I did label them all just incase.

I have two torque wrenches (a Lb-ft one and a Lb-in one) and had them before I even had a job that needed them I was capable of doing.

When I took the head off There was a lot of oil between two cylinders. It corresponds with where I seen the lead on the out side of the head. Maybe it never was the need and it did run round like Jeff R said but when I ran the dye test I seen no UV glow at either corner of the block, just out the middle.

I found the ground strap at the back of the head. I have made a note to make sure that gets reconnected when it is going back in.

My plan for parts to replace is the following:

Fel-Pro head gaskets
Push Rods (if its recommended I do, its $50 for all 12 of them)
Head bolts
Cam Sync Sensor - I bought a duralast one from Autozone but afterwards I read a lot of bad stuff about them failing very quickly. I was going to replace it with a MotorCraft one after reading horror stories of them failing and dropping oil pressure and killing the engine.

When I replaced it last time I just made markings on the old one and block and lined it up by eye. It ran absolutely fine with no misses or CEL but I agonized over the positioning and worried I got it wrong. This time round I bought the alignment tool and was just going to crank the engine round until the cam sync was lined up I could drop the tool in. I am not confident about finding TDC but maybe it will be easy with the heads off now! :)

Just to summarize my questions:

1. Not a question but THANK YOU again!
2. Do the valves need to come out to put new valve stem seals in?
3. Is there any maintenance I need to be doing for the piston liners, lifters etc to stop them rusting while its apart for a week.
4. Should I be replacing the push rods? They look straight but I am not sure if its good practice to just replace them while they are out?

I have attached some pictures of the heads, I am concerned about the rust build up in the water ports. The old owner looks to have put water in there. I have flushed it twice but still the coolant it brown. I have bought new green coolant (per your recommendation) and wondered if there was any other flushing I can do before putting this in. As you can see in the pic it looks like some of the holes are almost rusted closed.


Maybe you are right, I am still learning hence asking so many silly questions. I put the UV dye in and there was no dye in the corners of the head, but it was running out the middle of the head. Its entirely possible that it was running from elsewhere but I just rebuilt from the intake manifold back up and it didn't seem to fix it. I am sure someone with much more experience would have given a better diagnosis.

 

The areas that I pointed out in the photos are of some concern _ they show coolant seepage.
The heads should be checked for cracks and warpage.

Hopefully the block will clean up.

If your worried about the bores rusting while it's apart, just spray some WD40 in there, or any oil from a spray can.
Bores rust if the engine is left lying around apart for weeks in damp environment.

Push rods are OK if they are rolled on a piece of glass and show no signs of being bent.
Make sure the hole in them is clean, that feeds oil to the rocker arms and valve tips.
If the push rods are impossibly plugged, then it would be easier to replace them then to try clean them.
Hold them up to a bright light and you can easily see through them and how clean they are.

If you want to replace something, replace your lifters, lifters get "varnished" up badly due to lack of maintenance. (no oil changes and too many short runs)
When this happens new oil can't enter the internal workings and they don't function.
This can lead to burnt valves.
Due to the amount of sludge in your engine, I would replace them.

If in fact there was a stuck valve, it's quite possible that one valve wasn't getting any oil on its rocker arm.
The lack of oil would account for the valve sticking _ if in fact that is what happened.
Valves just don't stick all on their own, something has to cause that to happen.

About your heads...
When ever I do an engine, I just give my machine shop carte-blanche.
Parts for these trucks are not expensive _ new guides, valves and seals all around.
It doesn't make sense to put all this time on removing the heads and not do it properly.
Some just get reconditioned heads, it depends on how good your machine shop is, there are some real idiots out there.

EDIT:
Melling sells them in sets of 4 for only 32 bucks _ so 32 x 3=96 _ cheap piece of mind.
http://www.rockauto.com/en/catalog/f...ve+lifter,5548

Exhaust and intake valves are inexpensive.

http://www.rockauto.com/en/catalog/f...ust+valve,5328

http://www.rockauto.com/en/catalog/f...ake+valve,5544

Guides are cheap too.

http://www.rockauto.com/en/catalog/f...lve+guide,5776

 

Thanks for the reply Jeff.

I must say I'm starting to feel extremely overwhelmed with the task I've taken on so I'm having to take a step back and remind myself it can all be put back together! I bought this truck as a beater to learn on and it's suddenly got real expensive real quick!

I visually checked for cracks but I didn't see any. My plan was to ask the machine shop to check for cracks first before doing any work. The passenger side head did just get new valves etc (less than 500 miles ago) so should I be replacing these with the same valves I'm putting in the drivers side? Would different brands of valves cause any sort of unbalance?

I took a rag earlier today and soaked it in oil and wiped down the bores. I'll see if I have a spray can next. If they did get surface rust on them is that a big issue that involves taking the block to the shop or would it remove itself as soon as the engine started up?

In terms of cleaning the block mating surface I was just going to use a utility blade to get the worst off. Then some steel wool, use a dremel with a polish pad on it then some carb cleaner. Would that do the trick to get them clean for a nice mating surface?

Ok I'll take a look at the push rods and see if I can see through them. The truck has clearly not been well cared for in the past so I expect them to be clogged.

I've tried searching YouTube for videos on removing the lifters but there doesn't seem to be a huge selection of videos on the subject. The only one I can find is for a different vehicle but they just use a magnet to pop them out. Is it really that easy to get them out? I also read mixed reviews saying putting new lifters on an old cam can cause failures. Is there any truth to that? People are suggesting a new can but at this point it would almost be a new engine.

This is going to sound really silly, but do I order the parts such as valves etc and take them to the machine shop or do they supply the parts? I live in Austin Tx and having a hard time finding any shop that will even call me back. Is there any disadvantages to getting a fully returned head opposed to machining my one? I appreciate you sending links to the parts over.

One other question I had. I'm the intake manifold some of the studs to mount the plastic intake on to have had the tops rounded. I wanted to replace them but it seems impossible to find the correct studs. I've seen some people just buy a threaded bar from the hardware store and cut it to length. Is that really the only option? I just have the replacement gasket in my set but it's not causing an issue presently so I'm not sure if I should just leave it.

Finally can I ask your opinion on the cam sensor. Is it something I should replace while I have everything out. It looks a nightmare to replace when the intake manifold is in place but it's also running nearly $150 for the unit with the sensor. I've read quite a few post of people replacing them due to them chirping and would like to be proactive. I'm just getting concerned I'm spending nearly as much on the truck on repairs as I paid for it.

As always, you have no idea how much I appreciate the plain simple responses I'm getting! I'm keen to learn and hope one day I can be the guy offering advice.

 

Thanks for the reply Jeff.

I must say I'm starting to feel extremely overwhelmed with the task I've taken on so I'm having to take a step back and remind myself it can all be put back together! I bought this truck as a beater to learn on and it's suddenly got real expensive real quick!

Cars are money pits, you got yours cheap because the owner knew what it was going to take to get it running properly.
I just spent 3400.00$ on mine doing a complete engine rebuild.

I visually checked for cracks but I didn't see any. My plan was to ask the machine shop to check for cracks first before doing any work. The passenger side head did just get new valves etc (less than 500 miles ago) so should I be replacing these with the same valves I'm putting in the drivers side? Would different brands of valves cause any sort of unbalance?

If you're sure the valves are new on the passenger side, then leave them. You can visually check for cracks, but the machine shop does this with a strong magnet and iron filings, the filings show up on any cracks _ much more accurate.
Have them check the surfaces of both heads, that's most important.
You can have them pressure tested too, more money, but piece of mind.

I took a rag earlier today and soaked it in oil and wiped down the bores. I'll see if I have a spray can next. If they did get surface rust on them is that a big issue that involves taking the block to the shop or would it remove itself as soon as the engine started up?

Don't get too caught up with rusty bores, using your oily rag is fine. I like to use spray only because it's more convenient and the spray gets into the rings better. Like I said WD40 is fine for this and it's cheap.

In terms of cleaning the block mating surface I was just going to use a utility blade to get the worst off. Then some steel wool, use a dremel with a polish pad on it then some carb cleaner. Would that do the trick to get them clean for a nice mating surface?

Use a plastic putty knife, don't use any metal tools that will "nick" the block surface. Scuff pads are better then steel wool. Steel wool leaves steel crumbs everywhere and you don't want that.
Put rags in the bores so you don't get crap in there. Be carful when you pull the rags out so as not to have the stuff fall into the bores or get back into the bore that you just pulled the rag out.
An air compressor here is very useful for cleaning the bores if you have one.
Use brake cleaner right from the beginning to soften the gunk on the block, lacquer thinner also works well, but very smelly.

Ok I'll take a look at the push rods and see if I can see through them. The truck has clearly not been well cared for in the past so I expect them to be clogged.

I've tried searching YouTube for videos on removing the lifters but there doesn't seem to be a huge selection of videos on the subject. The only one I can find is for a different vehicle but they just use a magnet to pop them out. Is it really that easy to get them out? I also read mixed reviews saying putting new lifters on an old cam can cause failures. Is there any truth to that? People are suggesting a new can but at this point it would almost be a new engine.

The lifters are just siting in there, they will have varnish build up on the outside, so they may not come out easily. Work them back and forth with WD40 and they will eventually come out.
This engine uses roller lifters, so cam wear will be minimal, nothing to worry about using new lifters.

This is going to sound really silly, but do I order the parts such as valves etc and take them to the machine shop or do they supply the parts? I live in Austin Tx and having a hard time finding any shop that will even call me back. Is there any disadvantages to getting a fully returned head opposed to machining my one? I appreciate you sending links to the parts over.

Take your heads into the machine shop and discuss it with them. Very often it can be less expensive to get a head ready to go with new valves and guides. Machine shops can get the bits for you or you can supply the parts. If they supply the parts and something goes wrong, then it's on their head, but costs more because they have to warranty it.

One other question I had. I'm the intake manifold some of the studs to mount the plastic intake on to have had the tops rounded. I wanted to replace them but it seems impossible to find the correct studs. I've seen some people just buy a threaded bar from the hardware store and cut it to length. Is that really the only option? I just have the replacement gasket in my set but it's not causing an issue presently so I'm not sure if I should just leave it.

Ford should be able to order new studs, but expensive. Maybe the auto wrecker. That ready-rod stuff is usually made of cheap soft steel, don't use that. You may be able to get a high quality long bolt and make you own stud from that.
Take some pictures of the rounded studs and I should be able to help you with that.

Finally can I ask your opinion on the cam sensor. Is it something I should replace while I have everything out. It looks a nightmare to replace when the intake manifold is in place but it's also running nearly $150 for the unit with the sensor. I've read quite a few post of people replacing them due to them chirping and would like to be proactive. I'm just getting concerned I'm spending nearly as much on the truck on repairs as I paid for it.

If the synchronizer (the mechanical part) has no side to side play in it, then you can re-use it. It's OK to work some oil on the sleeve bearing if it's dry and noisey _ I use Tri-Flow every 6 months to a year to keep mine lubricated.

As always, you have no idea how much I appreciate the plain simple responses I'm getting! I'm keen to learn and hope one day I can be the guy offering advice.

Don't get too caught up in all of this, it will all come together.
Just be carful when cleaning the block surface not to damage it, don't use the Dremel tool for any thing.

 

1997 FORD RANGER 4.0L V6 Cylinder Head | RockAuto

Heads are cheap, you can get a head blank where you supply the new valves and seals and you re-use you springs, collars and keepers.

Or get a complete head where you re-use your rocker arms.

 

+1 on Jeff's suggestions

Yes, avoid metal cleaning tools on block/head mating surfaces, scotch brite is a good alternative to steel wool.

Unless you are going to leave heads off for a few months don't worry about rust, just wipe it off before assembly.

Only valve springs are removed when replacing valve stem seals, you can do it if you have a valve spring compressor, but if not then let machine shop do it.

Machine shop will pressure check head after cleaning but before surfacing, standard procedure, so any cracks would be found.

There are oil passages in the center of the head/block they feed the Rocker assemblies

 

Ron, so the 4 litre heads have internal oil passages ?
So if the head gasket was questionable, then it could also leak as Scott's die test suggested ?