Firefyter-Emt

Ok.. here is one for you.. This may not be what is wrong, but I hope and pray it is..

I dropped off my 4Runner off last night, and I talk to the guy, and he had a thought which takes a little to think through, but it is possiable.. He said that cam timing could do this.. If the cam is out of time the valves open at diffrent timeing than they should and there is too much room in the compression chamber to compress to a high PSI. Basicly before the piston has the stored cubic feet of air compressed fully the intake valve ehxaust valve open pushing the rest of the air out the exhaust (or intake??) Now he is not sure, and I am not sure and The timing was dead nuts on, and set with a light.. However, the belt was new, then R&I the next day a year ago.. Well I didn't want to get into the bottom half of the blet when I did the motor.. Could it have jumped time on a head?? It could of.. I just have never thought of this theroy in relation to having no compression (or very low compression) but it is possiable to happen... I should know by the end of the week..

FattyCBR

Yes messed up cam timing can potentially produce those symptoms. Your best bet if you have bad compressions numbers is a leakdown test though. You would be able to determine if your problem is your HG, rings, or valves, and if it's not any of those it may be your cam timing.

oly884

I think that that's very possible that you could have got off a tooth.

Also, really off topic, but is a little seepage from around the valve covers normal on a new engine?

Firefyter-Emt

Well 1st off.. I didn't "get" the timing a tooth off, it would of had to slip.. I marked the old belt and had set the timing afterwards.. Plus, it was good for 3k and it started quickly running rough ( I can not say if it was in one day or not) so it would of had to jump time.. Which, like I sad, I had R&I'd the T-Belt twice. I didn't have a compressor at home to do a leak down, but oil in the chamber had no effect, which points to the rings beeing good.. Plus I have no oil burning.. and I can hear the cmpression at the intake which would lead me to think the intake valve is open.. so if the piston was in the compression stroke while the intake was still open, I could get that same sound out of it.. and then it would shut while it "may" be close to being toped out and the valves could even show a vaccume while the piston was going back down if the valves are closed.. It makes sence to me... Now I wish I had checked the timing (But it is the right head, and the dist is on the left head.. so it could still be in time...

Firefyter-Emt

and no, a little seepage is not normal..