I bought a 92 Toyota extra-cab V6 4 wheel drive pick up last April. Ever sense I've drove it away, there was no compression in the #4 cylinder. I have just tore down the engine and found that the exhaust valve was not seating. That explains the no compression but there are no signs of why. I am pulling my hair out on this one! The spring is in the right spec and the cam specs out right too. The lifter was fine and the valve itself is not bent. The valve guide seems fine and the valve moves freely in the guide. The only thing that comes to mind is a warped head, but the head gasket was not compromised. Someone please help me before I go crazy!!! If there are any ideas it would be much appreciated. I love the truck it is beautiful, has no rust and the trany and 4 wheel drive are flawless.

 

Have you checked the valve adjustment, could be shimmed too tight holding the valve open, also check the valve seat that its not being hammered into the head or the valve face is not tuliped dropping the valve too far into the seat.

 

I did check the gap and it was within the spec and the seat was full of carbon as if the valve hasn't touched it in a while. I will check to see if the seat had been hammered into the head, didn't think of that. Thanks!

 

a 5vzfe would fix all of the 3vz-e's problems and isnt hard to swap

check it out on yotatech.com

 

Its a 3VZ

 

I agree! I love mine! Mine really gets up and goes and impresses me everytime I hit the throttle. As much as I love the indestructibility of the 22r's, anyone I've ever owned doesn't even compare to the power of my 3VZ.

My92pickup: Hope you get it figured out man, wish I could help you.

 

Well I have tested the length of the valve stem, no stretching. But I did find a lot of play left and right in the valve stem guides. The intake valves have very little play left and right in their guides. I,m not sure why there is so much in the exhaust valves. I am sending the heads out to get new exhaust valve guides put in and the seats re-milled. I'm also getting new exhaust valves as well. Got my fingers crossed that that does the trick!

 

Thats a strange one, you didn't say how well the engine ran before even with no compression, did it smoke, use oil, lots of blow-by? possible sloppy piston to wall clearance, broken ring, even excessive ring gap and or gaps aligned on the rings. If the gasket was good, no signs of anything holding the valves open, like carbon, or adjustment, camshaft specs out good, how about a cracked head? gotta be somewhere between the valve and the sealing of the rings thats letting the pressure out. Good luck.

ps. the exhaust guides normally run a little looser than the intakes, they run hotter, but not excessive amounts.

 

Trade you mine... Its torn apart cuz the head gaskets blew... Still wana trade...?

 

The truck ran OK even without #4. It had a loss in power but didn't smoke or use oil. There was quite a bit of carbon on #4 exhaust seat and the timing belt was stretched. I didn't mention it because I didn't think that it wouldn't let only one cylinder seal. But now that I think of it, it would allow the carbon to build up.

Nook, now that you mentioned that the exhaust guides are always larger for the expansion of heat makes me wonder if new guides are really needed? I'll have to talk to the machinist on Mon.

P.S. I also thought of bad rings in that cylinder, but if that was the case the spark plug would be all wet with oil. The spark plug is dry only a little but of carbon build up.