ToyYoda

#1 - 190
#2 - 192
#3 - 178
#4 - 130

So the guy I bought the truck from stalled out in water and sucked some water into the intake, I'm pretty sure because the engine was having a rough time running for a while after. Then, it started running halfway decent after the battery was changed; the old one was 100% dead. My motor has 203k miles on it and I'm wondering if a new cylinder head would be good enough or if I should just wait for this engine to totally break and install a longblock. I'm thinking it's the valves that are the issue as I can hear what sounds like knocking rockers from the #4 cylinder area under acceleration only. The truck runs great now, other than the slight knocking sound and has decent power for having 33" tires. What would yall do?

84sr5yoty

Is this a 22re?

Adjust your valves. I've seen very poor compression readings become normal just from properly adjusting the valves. Cyl. 1&2 are kinda of high in compression which is usually a sign of carbon build-up. A couple of rounds with seafoam should completely rid the motor of carbon.

dcg9381

IF it is legitimately water related, it's most likely a mildly bent rod..
"valve knock" is likely something else.. You can adjust valves on this motor fairly easily, if you think it's valves, check it out.

In my experience when the 22r-series goes (bad compression) - it's usually rings, but a leak down test can help you make that determination.

In your case, I'd suggest a leak down. If the leak down is fine and you still have bad compression in #4, I'll bet you bent something.

IF you wait until it "totally breaks" you make have a rod through the block issue, which can mean you're out a core motor... I'd figure it out.. You can get an OEM rod used for under $20 for a rebuild. A worked over set, $140-$160 ready to go back in.. Either way, at 200k+ you're looking at a rebuild.

ToyYoda

It's a 22RE-C. I think if it were rings, it would have low but somewhat equal compression on all cylinders. I've noticed it's rare for stock engines with no turbo to just randomly crack a ring or wear out more on one cylinder rather than the other. It probably had higher than normal copression because a thick motor oil was poured into each cylinder before tested. My plugs were all tan showing healthy combustion, proper air/fuel and no oil, detonation, etc., just low compression. I'm guessing the water made it's way to the back cylinders and bent some valves.

ovrrdrive

It could be a cracked ring or a scored cylinder...

Only way to know for sure is to pull the head.

brick privy

I don't see how water could bend valves because both the valves would be firmly seated on the head before there would be any pressure in the cylinder
to bend them.

I vote for bent rod theory.

ToyYoda

Yeah, you're probably right. I don't know if this makes any difference but when we added more oil into the cylinder, the compression went up 5psi. on #4 cyl. from 125 to 130.

waskillywabbit

iTrader: (-1)

Eliminate what you can so you know more and can guess less.

brick privy

When you do a compression test, first you should do it dry, with no oil. This gives you a base line measurement, then you add a small amount of oil to seal the rings so if the reading goes up then you know the rings are worn and it's not the valves. I think that in your case the rod is slightly bent so the piston is a little lower at the top of the stroke. This leaves a little more space above the piston which lowers the compression. By adding more oil you're taking up some of that space and raising the reading. That's why you run the test dry first, that gives the most accurate reading. When you add the oil you just want to see if the number goes up, if it does then the valves are sealing.

BTW it may not actually be a bent rod. It might be a bent wrist pin or even a bent piston. You won't know untill you take it apart, but I wouldn't run it too much like it is.

titicaca

the # 4 cyl is always the one that wears the most . the logic in this it that the cyl that is closest to the output of the crank , if the engine has been worked hard ie. towing , rooting, ect it would show more on the #4 cyl than the others. probabally want to consider a teardown/rebuild before too long. if there was a bunch of water in the cyl the piston could hydrolock and that water is the same as a piece of metal essentially, the piston could crack, the rod could bend, or the wrist pin could bend. if the rod or wrist pin bends you could have more stress on one side for the cyl wall and piston and cause them to wear out of round lowering compression. most likely your just experiencing normal wear from a lack of routine maintainence.

ToyYoda

I made a mistake earlier with my numbers. The #4 cylinder was at 120 and when more oil was added, it went up to 130. I'll do a compression test again with no oil and post up the numbers. The engine doesn't smoke at all, and runs pretty good too, just makes the knocking noise under load and showed bad compression numbers. Seems to me that 60psi. off on the #4 cyl. would have to have a bent rod bad enough to where the engine would misfire and run poorly and probably show signs on the plugs too.

84sr5yoty

This proves the problem isn't ring related and now points to the valves. Check the valve clearances before rechecking compression psi!!!

ttownjoeshow

i have a question simalar, i just bought a 86runner and the guy i bought it off of said that piston tested #1 150psi, 2 125, 3 125 and 4 150. my manual says 171 is standard and 128 is service, should i b worried about the 125's?
Oh and it has over heated on him once or twice. the rad was shot so i bought a new one.

Thanks in advance!

ovrrdrive

Low numbers in adjoining cylinders can mean a blown head gasket, but I would have expected to see numbers even lower than those if you had a problem like that.

I'd suggest doing the test again yourself and going through once dry, then giving it a good squirt of oil in each cylinder and doing it again.

Then maybe start your own thread to discuss the results.

ToyYoda

That's what I was thinking too. I'll pull off the valve cover and see what I can find and check clearances. I'm thinking about throwing a new cylinder head on it since they are cheap enough for a rebuilt. While doing that, I'll check the condition of the pistons and cylinder walls.

rdharper

I've got an '85 22rec and a 3VZE '94 4Runner.

Thought I'd learn how to do a compression test while the engines were running well.

The 22Rec has no problems... good mileage, good power, responsive, oil usage so low I don't keep track etc.

So I was surprised when I found the compression numbers were in the low 130's.

I'm thinking I may not be getting enough air in to get accurate readings. If that is the problem, what is the easiest way to get adequate air in to do the test?

ToyYoda

Make sure all the plugs are pulled and crank the engine over for about 6 seconds. What type of compression tester do you have? The best one is one that will screw into the plug hole and seal with a rubber o-ring, the o-ring will need oil on it to make a good seal.

rdharper

I do have the screw type... didn't add oil to the o-ring... doubt that would make a difference for the design I have (fairly deep), but it can't hurt so I'll try it next time.. thanks.

ToyYoda

rdharper, what were your compression numbers?

rdharper

137,129,134,132