Oily substance in intake manifold
 

Hello guys,


today I changed the old, warped manifolds for new ones. While doing so I noticed an oily substance trapped below the valves in block and intake manifold. It's only on the intake-side, the exhaust-side is clean without any traces of oil or other residues.



I do not have any steam from the exhaust (neither blue nor white) so I don't think it's from the piston rings / cylinders. I do however add special oil (probably similar to your MMO) to the fuel. Is it possible that a mixture of around 1:150 - 1:200 can cause this?
If so I will drive a tank without the oil and then significantly reduce the amount of oil I'm adding to the fuel.


Thanks and have a nice day,


Daniel

Re: Oily substance in intake manifold
 

What do your plugs look like?

Re: Oily substance in intake manifold
 

Yes, certain types of gas additives can do that. If it is not fouling the plugs or causing excess exhaust smoke, ignore it.
Some people use MMO just for the exhaust smell.
Some people use castor oil just fo the smell.

Re: Oily substance in intake manifold
 

Gutentag Daniel,

What you have is normal, you will find that on all pre fuel injected cars that have a lot of miles on them. It probably builds up faster on our A's because we normally don't drive them as far or as fast as we do modern cars, nor do we ran them as hot.

Re: Oily substance in intake manifold
 

Could also be a little oil passing thru the valve guides. I would not worry about it if your plugs all look good.

My opinion,

Chris W.

Re: Oily substance in intake manifold
 

Hi guys,


sorry for the late replay.
The plugs look fine, they all did have a very thin layer of carbon, but I still have some trouble with the carb (idle jets keep being clogged due to very small particles, most likely grit from not being used for a long time) so I had to balance that out with the GAV. Cleaned up the idle jet this weekend and will keep an eye on the plugs.


Thanks everyone!


Greetings,


Daniel