22RE top end knock

[4x4banger]

I just checked out a truck yesterday that I am going to buy. Its a 93 ext cab with 22RE. Guy is selling it to me for 200 bucks because of a pretty loud top end knock. Before I tear into it I just want to see if I can get a good idea of what might be wrong.

History on the truck. Apparently lost an oil pump not too far back. Had it replaced. Then had good oil pressure, and was driven for a few months. Then on a drive of about 20 miles a knocking noise started, and was getting progressively louder. Only went on for a mile or so and was parked.

So I went to look at it. It starts right up. Gauge shows good oil pressure. There is a very loud and clear knock in the top end. Way too high to be a rod, and definitely not timing chain slap. It is a very consistent noise seemingly once per revolution. When I revved it a little it seems like i could get it to go away for a split second.... just barely.

So, what's the most likely culprit here? I'm hoping for a stuck valve or something so I can just throw a reman head on it and be done with it. This truck is in great shape. Straight body, solid frame. Definitely worth making a runner again.

I know this is kind of a shot in the dark without pulling the valve cover and taking a look. Just wondering if what I am describing is something you guys have dealt with, so I might know what I am up against here.

[whomadewho]

You did not buy the truck you stole it. Excellent buy. It almost sounds like a rocker arm or a cam lobe. Does the truck have a miss at idle? You may want to consider checking compression,if you find a cylinder with low compression this could indicate where the bad lobe or rocker is located. With the engine at idle pull each plug wire, and see if the knock stops. If you pull a wire and the knock stops this maybe a bad thing -(wrist pin, or a bad piston) Open the oil filler cap ( engine running at idle) If there is a lot of blow by this could mean you have a piston issue. There is a chance the nut came loose on the rocker shaft. I assume you checked the fly wheel etc. GOOD LUCK

[DeadlyPeace]

May 23, 2011 18:11:22 GMT -5 whomadewho said:

You did not buy the truck you stole it. Excellent buy. It almost sounds like a rocker arm or a cam lobe.
GOOD LUCK

x2

[4x4banger]

whomadewho, thanks for the advice. Sounds like a good way to narrow down the problem. I'm towing it home tomorrow, and I'll see what I find.

[whomadewho]

If it turns out to be a rocker arm assembly before you remove the bolts MAKE SURE YOU DRAIN THE BLOCK COMPLETELY. Removing the rocker assembly (head bolts). There is a chance when you do the R&R of the rocker assembly, the head gasket MAY leak. Myself just an opinion,I would roll the dice and not replace the gasket. Just be careful not to move the head when you remove the bolts. To be on the safe side who may want to use some kind of block sealer. Before you start you may want to check the frame rails especially above the fuel tank. Do not make the mistake that I did,the body was rust free so I dropped 3 grand into the engine, and discovered the rail was rusted above the fuel tank. Even though you stole the truck,I mean bought it, you still want to keep the overhead low until you are sure what you have. Keep us posted.

[4x4banger]

I just pulled the valve cover. It couldn't possibly be this easy! All the valves and rockers look fine. Middle cam bearing cap is broken. I know these don't have cam bearings, but I don't know what else to call it.

So my only dilemma: I obviously have to pull the head bolts to take off the rocker assembly in order to change this part. It would be really nice not to pull the head and change out the head gasket. Anyone ever pulled the head bolts but kept the head on, and reinstalled them without changing the gasket? I don't want to do this and immediately blow a head gasket.

[DeadlyPeace]

If you're really careful not to move the head at all while the head bolts are out or loose then you might get lucky and not have to replace the head gasket. I've done it a couple times, but normally perfer to just change the gasket while I'm there. Good luck!

[4x4banger]

Damn, looks like buying cam bearing caps is not really possible. Been reading up on it, and apparently they're somewhat head specific because they're machined together. Guess I'll just buy a reman head and put it on. Then I won't have to worry about this head gasket business. Certainly still worth it for what I paid for this truck.

[whomadewho]

Just my opinion I would roll the dice and replace the cap. The caps are machined, but the cap is held only by 2 bolts and no dowel pins. I would find a used cap - plastic gauge it,and if the clearance is good,go for it.

[DeadlyPeace]

Whomadewho has has a good idea. If anything you can use it as temp fix while you're waiting on a new head.

[whomadewho]

The problem with going with a remanufactured head,it usually doesn't stop there. It goes as long as I am replacing the head, I might as well replace the cam, timing gears,guides, rocker arms & shafts etc. If I owned & drove the truck for a few years, I might consider doing it. The bottom line - When you are finished the top end is going to be good,but the bottom half could be . I guess if I owned the truck, I would price out the head and the rest of the parts,change the cap, and put the money aside and if doesn't work out, use the money for part of the payment for a remanufactured engine.

[4x4banger]

Well I've been looking at reman and new heads. Looks like I can get away with one for $300 or so with new cam, valves, guides, etc... I am probably not going to keep this truck, as I already have a '95 ext cab 22RE. If it was my own rig I would totally jerry rig it, but given that I plan to sell it I kind of want to do it right. I can easily recoup any money i put into it (and then some!)

I just did some more work on the truck. I unplugged each wire one by one and ran it. No change in the noise. So can I safely assume it is not a wrist pin? Also I checked the compression. All cylinders are between 150 and 160 PSI, which is within spec. Also this truck does not have a misfire.

The only question I have is do you guys think this cam bearing cap is responsible for making all this noise? The only reason I ask is the other two caps look fine, so I can't imagine the cam is moving around all that much. But I suppose with the load of the rockers/springs its possible. I am tempted to run it for a sec with the valve cover off, even though I know that will make a hell of an oil mess. Anyone ever do that?

[whomadewho]

Running the engine with out the cover assembly, will make one hell of a mess. With a broken cap the settings on the rockers will change, this will present a knocking noise. When you assemble the engine a couple things to watch for - The bolts in the oil pump are not all the same size - Do not over tighten the bolt on top of the timing cover. I always run a tap down the bolt holes in the block (Head bolts) If your looking to save a lot of time adjusting the rockers - Goodson makes a tool Part #88800 its a screwdriver and a 12 mm socket in one tool. You can view it at Goodson .com. or you can reach them at - 1 - 800 -533 -8010 Also read up on new cam break in.

[4x4banger]

Damn! This project truck just got a lot more complicated. After pulling the head I pushed on the top of each piston, and #2 dropped a good amount. I rotated the crank back and pushed again. Sure enough this thing has a bunch of slop in it. It also happens to the be only cylinder that was about 10 psi less than the rest of them. I'm thinking wrist pin. I thought I could pull each plug wire and run it and if the knocking noise went away it was a wrist pin. I did that and the noise was always the same. However I did it by pulling the plug wire then starting it. I know now that I should have kept it running and then pulled the plug wire. But based on what I'm finding i think it is bad.

Next question. Assuming its the wrist pin and not the rod bearing (which i still don't think it is) is it possible to change out a piston/wrist pin without removing the engine? I'm thinking pull the oil pan. Disconnect the rod, push the piston up through the top of the block. Install new piston/wrist pin, and reinstall. If I go this route I would of course check the rod bearings anyway. Also I would go ahead and do all new pistons/rings.

I know getting the oil pain out is a PITA. But is what I am describing doable?

[DeadlyPeace]

It's easier to do with it out, but yeah it can be done as long as no machine work needs to be done to the block. I've rebuilt a few engines without removing the block. Just need to hone the cylinders before installing the pistons. If you never done this or don’t have a honing brush then it would cost least to pull the engine and take it to a local machine shop to have them hone it then it would to buy a honing brush and oil to do it yourself. Even if you can still see the cross hatch in the cylinders its still best to hone them just to make sure the rings set nicely.

[4x4banger]

It just keeps getting better.... I pulled the oil pan to pull out that piston. The problem is the rod bearing. It really didn't sound like a rod knock to me because all the noise I heard was on the top end. However i think the sound I was hearing was the piston hitting the head. There is a slight wear pattern on the top of the piston in the exact shape of the cylinder head. It is the only piston that looks like that.

Damn.... I was really hoping this wouldn't turn into this big of a project. Crank journal is grooved. Rod is as well. So that all needs to be replaced. Gonna start weighing rebuilding this one vs. buying a reman.

[whomadewho]

Being the cylinder head has issues A re manufactured engine may be the best choice. IF the crank journal cant be ground,the new or used crank shaft, will have to be line bored. Then there is the oil pump,timing chain, possible rockers,and rocker shafts, head bolts. Plus the machine shop labor,gasket set,rod & main bearings etc. The bottom line, it sounds like you are trying to make a fruit salad out of HORSE SH;;. Price out a rebuilt with some one that offers the best and longest warranty,and will stand by it. Maybe someone can chime in and point you in the right direction.

[whomadewho]

Just an opinion,being you are going to sell the vehicle,rather than replacing the engine I would hang a FOR SALE sign on the truck for 7 or 8 hundred dollars plus,and try selling it that way.

[95yoter]

Sounds like a rocker arm could be warped or something.... But if You find bottom end issues i.e. bad wristpin, rod bearing, main bearings.. whatever... I pull the motor... Its not worth taking a chance that only one piston or one cylinder has a knock or whatever. If I hear a bottom end knock I generally pull the motor if I plan on keeping the truck and not flipping it. If I were flipping it MAYBE I wouldn't pull the motor and put it on the stand but rebuilding the bottom end is generally the best answer... like someone said before you want to run a nice cross hatch in each cylinder no matter what... and new chromoly rings... Just inspect and oil the wristpins, they don't necessarily need to be replaced. I can show ya some pics of a rebuilt 22re I am doing right now...

Attachments:

[95yoter]

22re