86 intake manifold oily
Thread Starter
Racer
Joined: Sep 2002
Posts: 420
Likes: 1
From: SAN DIEGO CA
86 intake manifold oily
I took off the intake manifold because of a leak in the front and noticed that the intakes for heads and inside the manifold had a thin light layer of oil on them, every cylinder. I just had the heads rebuilt and the engine cant have more than 1000 miles on it since the rebuild. I don't remember seeing this the last time I did the intake. I do have compression of about 190 in each compression test I did about a month ago. Could that cause the oil? is that normal? I didn't see any white smoke coming out the tailpipe
383 stroker
200 cc dart pro heads ported
lingenfelter intake and tpis base
58mm throttle
383 stroker
200 cc dart pro heads ported
lingenfelter intake and tpis base
58mm throttle
Thread Starter
Racer
Joined: Sep 2002
Posts: 420
Likes: 1
From: SAN DIEGO CA
I just took a look at the superram box and the throttle body blades are like new. I did add some dye to the engine to diagnose an oil leak but that's all. blow by? I really hope I don't have to pull the engine. anything else I should check for?
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
It is your intake gaskets. add extra sealant on the gasket when you put it back together.
Remember, if you use sealant that smells like vinegar, it will eat holes in your intake manifold.
What not to use? the blue sealant, the gray that smells like vinegar and the black that has the same smell.
Remember, if you use sealant that smells like vinegar, it will eat holes in your intake manifold.
What not to use? the blue sealant, the gray that smells like vinegar and the black that has the same smell.
Thread Starter
Racer
Joined: Sep 2002
Posts: 420
Likes: 1
From: SAN DIEGO CA
im hoping its the intake gaskets that were leaking. When I put the coolant dye in it should it was coming out of the cork gasket that was in the intake seal kit. These are the gaskets that go in the front and back. Im thinking it was leaking out of the front water jacket on the passenger side. At least im hoping. I was thinking of using Toyota black sealant. Ive used it before and it sealed nicely. I didn't use much sealant and was relying on the thin blue sealant that was manufactured on the intake gasket itself
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
Remember, the intake passages on the manifold are oil on one side and vacuum on the other. if there is a slight mis match in machining, the intake gasket gets pinched on one side, and the other side is a little loose. With hot and cold cycling of the engine, the gaskets squeeze and then get unsqueezed, and the looser side of the gasket will eventually compress, and the oil will find a way into the intake. Since oil creeps, it will find it's way up a little ways, but most always be heavier in the head port.
Last edited by coupeguy2001; Aug 15, 2013 at 10:00 AM.
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Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
I bought a Fel-Pro intake gasket set and it did not come with end gaskets. There was a tube of RTV sealer in the box.
The "vinegar smell" is acetic acid. It is used as an inhibitor to keep the RTV from curing. The RTV cures when the acetic acid evaporates. That was old technology and the newer versions of RTV use a different inhibitor that doesn't smell so bad. Look for "oxygen sensor safe" RTV, as the wrong kind can poison your O2 sensor.
The "vinegar smell" is acetic acid. It is used as an inhibitor to keep the RTV from curing. The RTV cures when the acetic acid evaporates. That was old technology and the newer versions of RTV use a different inhibitor that doesn't smell so bad. Look for "oxygen sensor safe" RTV, as the wrong kind can poison your O2 sensor.
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
When I was running a SuperRam (10+ years), I did not run a pcv. Still there was oil in the runners. The reversion from these long runner intake systems is pretty amazing. Depending on camshaft overlap, combustion poo is pulled into the runners resulting in an oily film. My motors did not burn oil, but still upon disassembly of the intakes, there was always a puddle of oil in each runner. This happened on different motors with different rebuilds every time. I wouldn't worry about it.
Advanced
Joined: Apr 2012
Posts: 52
Likes: 0
From: Salt Lake City Utah
I agree 100% with 383 Vett. He knows exactly what the issue is, reversion. On the silicone Honda Bond is the best but expensive. The grey permatex works almost as well. I have had leaks with the blue I would never use it. The grey beats the black.