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I've had a fairly persistent leak which I'm thinking is a somewhat common one, but I can't really see where the leak would be coming from. But I've got a fair amount of oil pooling to the side of the oil filler tube. Initailly I had thought it was coming from there or from where the dipstick goes into the block, so I had replaced the o-rings on both where the dipstick goes in and two on the oil filler tube itself and they are nice and tight now. Is there a tube somewhere underneath the intake manifold that sends oil that could be cracked and leaking? This car likes to ping under load once it gets warm too, going up a slight hill at low RPM, could there be a break in an oil line which is letting excess air get into the system and cause the car to run lean? Or am I combining two different issues?
AOS seals or rear balance shaft seal, or balance shaft housing seal itself.
AOS (air oil separator) is combined with what you call "oil filler tube" - there are two seals, an upper and lower (the lower is shown in your photo). Its like a very basic PCV system. Requires removal of intake manifold, then should be very easy to access.
Last edited by walfreyydo; 07-26-2023 at 10:36 AM.
Thanks mate! Yeah I knew I wasn't referring to the AOS by it's correct name, had a lapse of memory hah. I've already replaced the two O-rings that are where the unit connects to the engine, the upper and lower one (the one I circled in my pic), are there other seals in this system that can become deteriorated?
Check the larger vacuum nipple coming from the bottom of the intake manifold plenum area. The hose to it may be cracked, loose or detached. Also the steel tube nipple can come loose from the aluminum manifold.
I have the intake manifold off of my ‘83. I was appalled when I discovered BOTH of the steel nipples were able to be very easily removed from the manifold casting. I think that some high temp epoxy is in order here, combined with a bit of RTV on the outside of the insertion point for additional sealing. Just saying.
07-26-2023, 06:23 AM
Leak Coming from Somewhere Under Intake Manifold
