Please Help Confirm Bad Valve Seats **PICTURE** - Ranger-Forums - The Ultimate Ford Ranger Resource


2.9L & 3.0L V6 Tech General discussion of 2.9L and 3.0L V6 Ford Ranger engines.

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  #1  
Old 07-28-2016
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Please Help Confirm Bad Valve Seats **PICTURE**

I pulled a head, set it on its side, and put water in the exhaust ports. This is what its looking like. Really would like others people to confirm before I spend the money on new heads.

https://drive.google.com/file/d/0B3Z...ew?usp=sharing
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Old 07-28-2016
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It's carboned up _ probably what's allowing the water to leak in your test.
If the heads are not cracked, why not take them to a machine shop and have them rebuild them.

The water galleries are blocked a bit, what does the block look like ?

A clean combustion chamber indicates that there is a crack in the head (some times the crack is underneath one of the valve seats).
The water getting in there steam cleans it and I don't see any of this.

I've read these engines have a problem with valve seats coming lose, so others with more experience may comment about this.

If this was my engine I would take a trip to the machine shop first before spending money on new heads.

I would also figure out why there is so much carbon build up.
I know if the EGR systems are not running right the computer dumps fuel into the engine _ that would certainly cause fouling.
Dirty and/or worn out injectors too, etc...

Last edited by Jeff R 1; 07-28-2016 at 09:13 AM.
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Old 07-28-2016
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The reason I want to just go with refurbed heads is that they come with upgraded valve seats. One ebay you can get them with all bolts and gaskets fully machined for 400$ I hear machine job runs 300...



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Originally Posted by Jeff R 1 View Post
It's carboned up _ probably what's allowing the water to leak in your test.
If the heads are not cracked, why not take them to a machine shop and have them rebuild them.
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Old 07-28-2016
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All I have to say about that is beware of Chinese steel and cheap head gasket sets.
But I have also read that the Chinese heads are heavier made where they need to be so they are less prone to cracking.

It's up to you.

It will be interesting to see what others have to say about this
I could be way off or on the nose.

I bought some realy cheap Chinese rotors for my Mazda B2200 and they lasted longer then the more expensive Raybestos brand.

I think the problem with the Chinese stuff is you never what you're going to get.
There's no quality control, some days it's good and some days it's bad.
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Old 07-28-2016
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Can't tell from picture the volume of water leaking out, but doesn't look like much??

A valve is a metal on metal "seal" so is NOT air tight or water tight, and not suppose to be.
It will leak some water unless brand new and then it will just leak less.
Leak down test with air pressure will show 5%-8% leakage on newer engine, 9%-12% on high milers

Water will pour out of a bad valve seat seal, not just leak out.

I would call up a few machine shops and get exact quotes on valve grind, surface, pressure test and cleaning, on my 4.0l heads the cleaning, pressure check and surfacing for both heads was $130, $65 per head, not sure what valve grind would add it is more labor than parts so can add quite a bit.

New anything these days is a gamble.
New used to mean tested and working
New now means you test it we will warranty it, but not your labor to put it in and take it out

I would rebuilt old ones if they are not cracked

Last edited by RonD; 07-28-2016 at 01:24 PM.
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Old 07-28-2016
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Like my old B2200 and my B3000, I plan on getting new valves rather then grinding the old ones.
The valves for these engines are quite inexpensive _ something like 9 bucks each...
Save the labour on grinding the old ones and all they have to do is cut the seats.
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Old 08-11-2016
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try rock auto for parts, just got a reman head for 180 ish
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Old 12-15-2016
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i pulled my heads off to replace the gaskets, and one side was fine, the other had a small cracks in the over both valves seats...the head is cracked, i was wondering if there is anyway to weld, jb weld, silver solder. anything like that so i dont have to drop 200 for a new head. I need to get to work, and just need it to run a while then im going to do an engine swap, or sell it and junk it for another car. i know the gaskets should be good, only drove it 3 times since it was replaced, and dont have the money and can't get to work. stop leak was tried but the heater hose connector broke during the headgasket change and it leaked all that out it got hot and the water in the radiator get spit out when it runs. anyone got any ideas for a cheap, jerry rig fix to get me by till i can swap the engine. i just got to get around town for a month. i was thinking welding the cracks and using a dremel to grind the bead down so it looks the same. a friend suggested silver solder, another said jb weld. anyone input would be greatly appreciated, and i do realize this is not the right way, or even close to the right way. Thanx
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Old 12-15-2016
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JB Weld won't stand up to the temperatures in the combustion chamber.
If you can find someone skilled enough, brazing usually is the choice for repairing cast iron. Silver solder is an alloy and has a lower melting point and because of that, brazing is better.
At any rate you will need an oxygen/acetylene torch to generate enough heat for the job.
It's always tricky though, heating the head up to melt the brazing rod may make the crack bigger.
You have to find the ends of the crack and drill a small hole to keep the crack from growing at each end when it's heated _ so the practice goes as I was told.
Personally I've never tried to braze up cracks in a cast iron head.
A jobber would probably want at least 100 bucks or more for the job anyway, so it may be a waste of money.
Even if you were successful, it may fail, plus the head is probably warped, so it may leak anyway around the gasket.
Keep in mind too because the crack is underneath the valve seat, there is no way to fully get at it with out removing the seat.

Personally if it was me and I wasn't planning on keeping the engine anyway, I would just throw it back together and carry lots of water with me. (don't even bother with anti-freeze)
You're in California so there's no chance of freezing.
It depends how bad the crack is and how much water the engine uses.

Last edited by Jeff R 1; 12-15-2016 at 04:06 PM.
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Old 12-15-2016
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thank you man,i have been trying to do that but its letting enough water or oil that it wont fire so im running on 3 cylinders or 4 if im lucky, and 100 bucks is about what a head at pick a part run i think, im not sure tho. Thanx again for the help and info, if you got any thing else im all ears. i'm trying to find a friend with a tig welder, or im going to try the silver solder, its all i can afford, but ill see about the oxy/sett torch, thank you man, any other advice or info is welcome, and thanx to this community its the second time you all have helped me out.
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Old 12-15-2016
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If you're going to use silver solder, you're still going to need allot of heat, so you may as well use brazing rod.
The silver solder I'm talking about has nickel, brass and silver in it _ not the low melt stuff.
You need to find someone with the right skill set _ someone who's been doing it for years.
At any rate, they won't be able to guarantee the job.

The problem with repairing cast iron is that it contains allot of carbon and when heated it oxidizes very quickly. When this happens what ever you're using to repair the crack with won't stick. Flux is used and that's where brazing comes in.
Not sure it it can be TIG welded though because of the high carbon content.
You can always ask.

Found this video _ interesting, but again, any jobber will tell you it's not worth it because a new blank head will only be a 100 bucks more.

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Old 12-15-2016
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Even if you under value your time at $1 hour, a $100 used crack free head is better than trying to fix a cracked head.

If you had a diesel head, or hard to find gas engine head, worth $1,000-$2,700 it would be worth it to at least to try.

4.0l OHV heads are just not that expensive relative to the time it takes to "try" fixes


When you weld a head, good enough to at least have a chance to seal, you usually warp it, so have to have it machined flat again, not free for that
If crack is at the common place for 4.0l OHVs then it is between the valve seats, so you have to remove the valves and seats, weld the crack and then machine for new seats and flatness.


And you can reused head gaskets as many times as you want, but the 2nd time to the 20th time has the same risks of failure.
First time you torque down a new head gaskets the metal ring seals the cylinders between head and block, once removed the metal ring can never seal very well again.

The 4.0l OHV head bolts are the same, torque-to-yield(TTY), they are made to stretch ONE TIME, that actually makes then stronger.
Once you remove the pressure, untighten them, they can't shrink back to old length, and they are now brittle.
You CAN reuse them you just SHOULD NOT reuse them, they will break, either when torquing down the last time or at some point down the road after repeated heat ups and cool downs.
That is just the way they are made, TTY bolts are better in all respects than "regular bolts", except that they should not be reused.

Last edited by RonD; 12-15-2016 at 07:34 PM.
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