Could it be manifold (IMRC) or sensor that controls runner flaps? Icant find any info for the 4.0. Also I read it could be Caron buildup. That doesn't seem right. It knocks at high rpm and sometimes it's quiet at idle.

 

4.0l SOHC engine runs 9.7:1 compression ratio, so will knock(ping) on regular 87 octane fuel.

So Ford added a Knock sensor to retard spark timing to prevent knocking if it is detected.

Knock sensor is under center of intake manifold and hard to get to, but I would at least check the wires, wires come out on passenger side of intake towards the front and connector is on or close to Valve cover on that side.

Location here in first diagram: | Repair Guides | Component Locations | Knock Sensor | AutoZone.com

I would unplug the sensors wires, this should put computer into a type of open loop that will retard the spark timing a bit, and you should also get a CEL(check engine light).
If you don't get a CEL then there could be a problem with computer.

Also run a tank of 93 octane and see if knocking goes away, it should, that would tell you if it is a knock sensor issue or "carbon build up" or EGR.

Carbon build up causes knocking because once heated up it will get hot spots that can pre-ignite fuel(ping/knock noise), if there is enough build up it also increases compression ratio, so double whammy, but not likely your problem, because working knock sensor would retard timing before you heard a knock.

EGR system also helps prevent knocking by cooling cylinders when engine is under load, this is done to lower NOx emissions but that is done by cooling cylinders, lol, hot cylinders pre-ignite fuel, but again Knock sensor should prevent that knocking.

 

Would a bad knock sensor trip a check engine light? Mine isn't on but I haven't run my scanner on it yet.

 

yes, it would, but sensor failure doesn't always fail in a way computer can "see", which is why I suggested unplugging the knock sensor to see if computer is even monitoring that sensor.

O2 sensors can fail Rich, computer doesn't recognize this, driver does when MPG starts going down.
Knock sensor could be telling computer everything is fine, only driver notices the pinging

 

It sounds loud like a bearing but seems to run fine other than that. Not a pinging from gas. Someone on YouTube said the runner flaps in manifold for a 2.3L but this is a 4.0. I don't want to trip any codes because I haven't got it inspected yet. NYS is hell with vehicle inspections and pretty much everything else too. They won't pass check engine light at all.

 

4.0l SOHC doesn't have runners.

An engine bearing knock is THERE, it won't come and go, or only be noticed at high RPM.

Run a tank of 93 octane, that will take pinging off the table.

You could also have a timing chain issue, that can make noise at specific RPMs.

Connecting rod knock can be heard at idle, if you unhook spark on one cylinder at a time while engine is idling the knock will go away when that cylinders spark is removed.
A connecting rod knock is caused by warn bearing and that cylinder firing.
When piston comes to TDC then just past TDC the crank pulls connecting rod down, that leaves a gap at the top between crank and connecting rod if bearing is worn, when cylinder fires connecting rod SLAMS into the crank, and creates the Knock noise.
So if you remove the spark there is no SLAM and no knock

 

If its a rod how much do they usually cost to fix. And how are the spark plugs in this truck. Do they break easy because I don't want to break a plug. My F-150 was horrible with plugs. BTW thanks for all your help.

 

Those were the Triton V8s and bad spark plug design.

4.0l SOHC spark plugs won't break but a few are hard to get at.

Bad rod means rebuild, because 1 rod bearing starting to fail means something is wrong with the whole system, usually oil system.

I have had cars and trucks that I had to cut out inner fenders and make covers/plates for them so I could change spark plugs easier.
newer spark plugs are often rated for 100k, but still, they can bury some so bad you have to unhook motor mount and jack up engine to get to them.

I have to say that automobile engineers and I have one thing in common, none of us believe in "intelligent design", but their belief is more apparent

 

How much does a rebuild cost. I don't want to do this my self in less I can save $2000. Then I might try it. Maybe cheaper to have a newer engine put in. The 4wd, tranny and everything works great. Just that damn noise.

 

I would first be absolutely sure what the noise is, few hundred dollars for mechanic to diagnose could be worth while.

Rebuild cost is area specific, basically it comes down to local hourly labor cost and local competition for that business.
Call a few local machine shops, get their price for rebuild of Ford 4.0l SOHC

Machine shops generally don't remove and reinstall engines, some do have mechanics and auto repair shops as part of their business.
If you don't want to do any labor at all then find one of these types of shops, most auto repair shops "send out" an engine for rebuild, and if there is a problem within warranty period you could be caught waiting a long while for the "blame" to be assessed when 2 companies are arguing about who's fault it is.

If you are comfortable with general wrench work and have the place to do it, you can rent a portable engine hoist and U-haul truck(unless you or a friend has another truck), for a day.
Engine can be removed in a day and dropped off at machine shop for rebuild.
Then rent hoist and truck again for another day to reinstall it.

What this will save you depends on the quotes you will get when you call around to find out what local shops would charge for this.
Removal should take no longer than 6 hours, reinstall 8 to 10 depending your memory :)

You can also look at the cost of an already rebuilt engine, long block(long block means heads are torqued down and timing chains will be in place and timed)
Short block means just lower end rebuild, pistons, rods and mains have been rebuilt, no heads included or timing chains for SOHC model.

Then get rebuilt long block shipped to you and rent the hoist for a few days to remove old engine and transfer all the parts needed over to the new engine, and reinstall it.
Then have old engine long block shipped back to source of rebuilt engine, as these sales are almost always exchanges, you usually have 30 days to get old engine back to them but that varies.

This option means less down time and less memory use, lol, trying to figure out what goes where.

 

So I found a Mazda 4.0 motor but I don't know if the parts are interchangeable. It a lot cheaper than reman engine or sending it out. I bought this truck for cheap and knew it would need repairs. My teenage son can work on it with me. I test drove it before I bought it and everything seemed OK. The manual hubs locked and 4wd button worked fine I thought. Drove it in 4wd a bit and tried it in reverse too. No noises. Been driving it a few days now with no steering issues at all. I checked the manual hubs today and they aren't working. Then the driver axle is loose and flopping behind hub. There's no axle nuts on the axles so how would they stay tight at all? The passenger axle is tight but seems to be locked into 4wd which I will have to check on because the hub is not locked. Will have to check transfer case next. I don't know why the driver axle is sloppy , maybe CV parts are completely busted. Might just sell it but I do like the stepside and would like to keep it if the cost and work is reasonable. Project truck right now.

 

OK, there are some "issues" here.
You have 2009 Ranger 4x4 with 4.0l SOHC engine listed as the truck we are talking about.

In 2001 Ford switched Rangers to "live axles" in the front, so no hubs, locking or otherwise.

In 2001 Ford switched Rangers from the 4.0l OHV engine to the 4.0l SOHC engine, totally different engines.

Mazda B4000 also got the 4.0l SOHC in 2001

So what year Ranger do you have???????
4.0l OHV didn't have a knock sensor, it didn't need one.

 

I just talked to a guy with a 4.0 efi 2000 automatic explorer motor. My 99 ranger also has the 4.0 efi motor. I can get it tomorrow for $250. I don't know if it will bolt up directly to my auto tranny and motor mounts, wiring etc. I'm really hoping it will. I don't want to waste money on amotor I can't use. He showed me pictures and they both say 4.0 efi so I think they're both the ohv motors.

 

My truck is a 99 with the 4.0 efi and manual locking rugged hubs. I made a mistake on the listing. Didn't notice . I will edit it.

 

You have a 4.0l OHV engine in 1999 Ranger, explorer can have either a 4.0l OHV or a 4.0l SOHC engine.
4.0l SOHC has a big plastic cover on the top front of the engine that says "4.0l SOHC" in big letters, can't miss it, and the SOHC looks totally different than OHV from the top.
You can't swap 4.0l SOHC into 4.0l OHV vehicle or visa versa.

EFI means electronic fuel injection, all Fords(trucks and cars) were EFI since about 1985, so is unrelated to what engine you need.

Your truck has no Knock sensor, it may have an EGR system, if EGR system isn't working well then engine can knock at higher RPMs when under load, accelerating.

4.0l OHV also doesn't get a timing chain rattle/knock.

And they rarely have any major problems at all, cracked head if they are overheated is about all the common problems they had.
Your 4.0l OHV was about as bullet proof of an engine as Ford ever made, so I would really investigate that knock because another engine won't fix it if it isn't a bearing knock you are hearing.


1999 Ranger 4x4s had Pulse Vacuum Hubs(PVH), they were junk even new, so yes you probably have AVM Rugged Ridge manual hubs.
Good read here on whats inside if you need to take them apart: 1998-2000 Ford Ranger Rugged Ridge (AVM) Locking Hubs

 

I don't know what it could be then. When I turn it on it does a hundred really loud knocks and then idles down to constant quiet knocks. The driver axle spins by hand and the passenger one won't spin at all even with hub unlocked. When I turn the 4wd switch on the driver side one won't turn by hand anymore. So I don't know if the passenger inner axle is not unlocking. I did this without hubs on to make sure they weren't the issue. I will have Mechanic check the engine I guess. The engine top says efi not sohc so I was told that meant it was the Ohv version of it.

 

yes, 4.0l OHV won't have SOHC but can have EFI on the top of engine, but that's on some not all 4.0l OHV, and many many engines have EFI.
Using EFI to ID an engine model would be like using OIL to ID it.
"Engine has OIL on a cap on the engine so is that the same engine?"

reminds me of a Blonde joke
Blonde: "where do I add the oil on my car?"
Mechanic: "look for a cap that has OIL written on it and remove that cap to pour oil in"
Blonde: "there is nothing like that on my engine"
Mechanic: "well tell me what you do see"
Blonde: " I see washer fluid, coolant, 710, and brake fluid"
Mechanic:" 710??, is that on a cap"
Blonde: "yes, 710 on a cap"
Mechanic: "try turning the cap around so it is upside down"
Blonde: "OK, oh wait someone must have installed it upside down, it says OIL now, what an idiot to install it upside down"

My wife always thought that was a stupid joke, but................
She called me the other day and said she was locked out of the car and in a hurry.
I said "you locked the keys in the car?"
No she said, the stupid key fob won't unlock the doors!!!
I said "did you try to use the key in the door?"
There was silence on the other end of the phone..............
No she does not have Blonde hair but I think she has the 1/2 the gene for it

An engine rod knock is usually quieter when oil is thicker, cold, then louder as oil warms up and thins out.

An exhaust manifold leak can sound just like a metallic Knock and will be louder when manifold is cold then get quieter as manifold heats up and metal expands to close the leak a bit.

Mechanic should be able to ID where the knock is coming from.


reads like you need to pull off the hub on that side and see why it isn't locking, see above link on how to do that.

 

I was thinking maybe exhaust today. That would be a little better fix I hope. The guy sent me a picture of his engine and it said 4.0 efi on manifold too. Does that mean they're the same? I took hub off and axle is still locked. Idk. It's not loose so that's good. I will look at link. Good jokes. The nut behind the wheel was always my favorite...lol

 

Yes, "loose nut" holding onto steering wheel is a good on as well

 

So do you think midas or muffler shop could check it quick or no.

 

Ok so I looked at the link. Those are the hubs I have so someone must have switched them. Maybe the loose axle is just a spring clip missing. I will check that tomorrow. The one hub is stripped and busted inside probably from loose axle. The other hub will not stay unlocked completely. Probably rusted a little. I tried spraying some wd in it but it didn't work. I really want to figure out why the axle won't spin with hub unlocked and 4wd switch off. I hope they didn't install man hub wrong.

 

Yes, muffler shop could check it.

The AVM hubs are the only ones that will work on a '99 Ranger, '98-'01 Rangers
There was Mile Marker as well but not sure on those

 

Guy at church said to check exhaust also. Maybe catalytic converter rattling. That blwould be a bonus. It's getting chilly here in upstate NY so the less I have to play out side the better.

 

So I drove the truck today because it was behaving. Then by 25 minutes it was knocking and banging a lot. I parked it and will be taking it to garage tomorrow. The axles and hubs are functioning correctly after further inspection earlier. The 2000 explorer engine that I found to swap is in fact an OHV 4.0. So everything should line up correctly and be very similar. It seems worth the risk for $250, especially if the garage tells me some astronomical repair number. I just hope they correctly diagnose it. I've never swapped an engine before. Does this ever work out well for anyone?

 

Engine exchange, same model engine, requires no special knowledge, just a lot of labor which is why it can cost alot at a shop.
In this day and age labor is expensive parts are not.

Engines are swapped daily, a vehicle worth close to $0 with bad engine is then worth street value with working engine, so it is worthwhile, even more so if you are keeping it as a daily driver.

Used engines can be a good deal or a nightmare, if you can hear the engine running that lessens the odds of the nightmare scenario, but bottom line is that you won't know if the $250 was a good deal until engine is in your vehicle and running for a few weeks.
4.0l OHV engine doesn't tend to have problems, except cracked heads from over heating, so is a fairly safe bet, but it IS still a BET, a gamble.

Rebuilt engine costs more and has a warranty, but warranty doesn't cover labor to exchange engine in case it does fail.

Most shops won't swap a used engine without you signing a no warranty statement, and upfront payment on the labor estimate.
Because even after swapping in the used engine they have know way of knowing it will even start or work, lol, and don't want take that chance, they are not Casinos no betting or gambling allowed :).

If they provide a rebuilt engine and swap it, then they will warranty engine and labor.