poppy

Thi is my first post here, be gentle. 93 truck 3sve My adventure started with a simple valve cover gasket replacement but has turned ugly fast. Right now I'm changing the front cam seals. Found a puddle of oil on the ground then tracked it to the seal. Compression test found 160 to 175 on all except #5 only 140 there. I put a new PCV when I did the gaskets. Every seal was leaking so I'm looking into why. the cam seal was pushed out from the pressure. When I checked the new PCV I was sucking air through it when it felt it closing off. I'm thinking the hose is old and collapsing when vacuum is applied. Anyone had similer symptoms. Rings maybe?? Valves?? Where could this pressure be coming from????

yayfortrees

The best way to find out exactly what is going on is a leakdown test. That will tell you (or a mechanic) what's going on with your #5 cylinder.

As for the PCV, there's not a vacuum there, at least not like a vacuum port on an intake. You could think of the crankcase pressure as an A/C electrical current, positive - negative - positive - negative. Basically, the PCV has to release that pressure, but shouldn't allow air to be sucked in under the vacuum. It probably can only be installed one way, but make sure it's installed correctly. And most likely, the hose is not collapsing due to vacuum.

As for the leaks, a valve cover gasket can be tricky, especially the first time you install one. That is probably the most difficult gasket to install without it leaking. When you said "every seal was leaking", was that only the valve cover gaskets? Did you use any gasket sealer like FIPG? Were all the surfaces perfectly clean and free of oil?

Hope this helps some. Welcome to YT!

thook

Crankcase pressure....

http://www.tpub.com/content/construc...14-P-30119.htm

http://wiki.answers.com/Q/What_can_c...gine_crankcase

My favorite site....

http://www.autoshop101.com/forms/h63.pdf

Just some info to digest on a google search. Uneven compression like that leans towards a ring or valve issue.

poppy

Thanx ytrees, thook Have been to many other sites but YT is probably the most extensive, with lots of great brains to pick. When I started my first search it seemed to me the 3.0 has more problems with gaskets, seals, odd oil leaks. I know the 22R is a tough act to follow ( have had 2 trucks, 2 Celicas ) But these 3SVE motors seem to be unusually leaky. The Toyota eggheads can't have made practically every gasket and seal to leak. I'm working on the theory that a lot of the leaks people are having are at least partly due to crankcase pressure, or I could just be full of s**t. With the built-in head gasket, valve issues they're bound to be leaky. I have no EGR or CAT problems that much is sure. I watched the oil shooting out of the cam seal which is how I ended up sitting in the corner with a timing belt wrapped around my neck. The doctors say it is not in fact Tourettes, but is due to an angry little man putting white marks on timing belts. I'm back. Anyway the PCV hose has a sharp bend that I think because of it's age is sort of fluttering with the rapid airflow fluctuations ( better ease up on the F key ) I have glommed a lot of great info here. I have a few mods and ideas to post ( used a nylon 1 1/4 P-trap seal to fix a sloppy shifter about 5 months ago , still nice and tight. just like me. ) Sorry I Hijacked my own thread but Thanx again, That crank pressure info had to be hard to find WHAT?

thook

Yeah, it took me hours....