been a long time since i've been on this board, but in an effort to resolve all of the issues with my car, this one has been ongoing - i am (literally) sucking down oil and apparently its source is thru the plenum. yesterday when i took it off to pop the injectors to verify whether or not they were leaking, the bolt under the egr port(?) on right side was a little wet when i removed it. when i took the plenum off, there was a path of oil leading down that passage to the ports at the front of the plenum, AND there was "standing oil" (pooled) near the rear end of the plenum, as well, namely around the IAT. i took the egr valve off, didn't see anything "wet" in there, but that port and the pcv port are all in line with each other and not knowing how all that works or is designed, i can't speculate if it's being drawn out of the valve cover area. i will add that at one time i just put in a breather cap in the valve cover to see if that were the issue, but didn't seem that it made any difference. on an average, it "burns" about 1 qt/500 miles... this is the main issue i need resolved now, so i hope you guys can help me out. obviously this creates a problem with fouling the plugs constantly and with it being a known issue, the car has been parked for some time... thanks in advance...

keith

 

How many miles on engine?
Is PCV valve working?

Under normal conds , CCV air goes from the port on the TB to pass side cover , through engine,out of PCV valve on drv side cover to the plenum ( under vac ).




At WOT when little vac in the intake , the fumes (w/ oil ) go out pass side cover back to the plenum ; your most likely source of oil in the intake
Commonly found when engine is worn and has lots of blow by
( or PCV not working ,meaning all engine fumes go back to the TB)

 

i have had this same issue with 4 differant engines and 2 differant cars
changing the pcv has never solved it
its always sucked pil in the ccv
one engine had 85k another has 20k another had 130k another had 4k
its like the pcv system just isnt as strong as it should be
my zz3 had 4k on it when installed maybe less there was no oil in the carb intake that i took off and the intake and exhaust ports showed no signs of valve stem leakage .
no oil leaks anywhere valve seals are not leaking , yet it still stucks oil in and even at 10k
now on the engine it used 2qts inbetween oil changes the plenum sucks so much oil in it just was not funny
the engine burns oil if the ccv is connected if i just use a open breather it stopped useing oil almost completely

 

Drain the oil and see if there is a bunch of 'gunk' in it. Like a build up of carbon. I had an engine doing the same thing, it drank oil and smoked.

The intake manifold gasket had burned through at the EGR port into the valley side of the intake. It was dumping exhaust into the inside of the engine (gunk in oil) along with pulling oil through the EGR system into the plenum (smoking and using oil).

RBob.

 

about 14k on a rebuild... never used oil this much when i had bad valve seals in the old motor... was just discussing same "most likely source" with a co-worker and that is going to be my next thing to check. when i had put the breather on the driver side in place of the pcv, the pass tubing was still connected to the t/b and still used the oil, so that all makes sense. only other thing i can think of that changed during the rebuild was milling the heads and i can't recall what size head gaskets i used, but all-in-all may have changed the geometry of the intake-to-head dimension and oil is being sucked in there, but that should go directly in to the pistons if that were the case... with all that being said, i'm not 100% sure the pass side valve cover has the baffles in it or not, or since i'm using different rockers, if the oiling is causing it to shoot up that tube, but when i get home today i hope to find out. thanks for the replies.

keith