I have searched and read a bunch of threads on oil leaks on the 3vze. I bought a 94 extended cab 4x4 for my daughter recently and have been chasing oil leaks ever since. I replaced the three gaskets on the oil cooler which I could see leaking so that is not the problem.


The oil is coming from the top of engine and coming down the bell housing on the passenger side. I have felt the back of the heads which seem dry, and see no obvious leaks from the valve covers or cam caps on the back of the head.


I just bought valve covers and will attempt to change them out tomorrow. Any ideas where else to look? since the exhaust crossover is in place it is really not possible to see the backside of the engine. Any suggestions would help as I am new to Toyota v6 engines.

 

I have the same engine and it burns oil a little faster than i would like but it's old and i just make sure to stay on top of it
Does it have the original head gasket? They seem to need to be replaced more than other toy engines but it's not a bad engine contrary to popular belief
Also, check that the oil filter is screwed on properly but If it's leaking from the top, could be head gasket but it sounds like you are changing the valve cover gaskets so that could help

 

Thanks for the reply, I changed out the valve cover gaskets yesterday, no sign of an obvious leak. This was kind of a pain but I got through it. I drove the truck tonight and the leak is still running off the passenger side of the bell housing and transmission.


I had cleaned everything up as best I could before working in it. I have it traced back to a rubber vent on the top of bell housing. Do you think my rear main in bad and throwing it off of the flywheel through the vent? This is the only possibility I can think of. The oil is definitely motor oil as it is relatively thin and does not smell like 90 wt. gear oil.


Anyone ever seen this happen on these V6 engines?

 

Thought I would take the time to update this thread in the event it can help someone out. Replacing the Valve cover gaskets did not help so they were not the cause of the oil leak. I really looked everything over well, using a mirror to determine no leaks behind the cam plugs and back of the intake.


I pulled the rubber boot back from the clutch fork and confirmed there was oil inside of the bell housing. This led me to believe the rear main was leaking. I ordered up the seal and went ahead with a new clutch as well.


After I got in and looked everything over, the rear main was not the culprit. There was oil sitting on top of the block and running inside of the bell housing through a bolt hole under the coolant sensor manifold.


The good news is that the new clutch is great, the bad news is that the oil leak is still there. I found a thread the suggested the head gasket may be the problem, although I cant seem to find it again. To the best of my knowledge there is no oil as art of the intake manifold, so I am reasonably sure the back side of the passenger side head is the culprit.


I may put this off for a while, the truck runs well and I can park where the mess from the leak isn't a problem.