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Sal mon

Oil in manifold????

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Chaps, forgive my ignorance but I'm fairly new to working on cars in general let alone rados. I do have a good background knowledge with engines from working on aircraft, but they stick a few different things in cars. Anyway my question is.......is it normal to find oil in the intake manifold? I found the overrun shut off valve hanging off the air box so decided to take it all apart and have a look inside for any crud....and found a fair amount of oil. Normally I would take this as a problem but in this case I'm not sure. The car was experiencing loss of power and stalling, which I think is to do with the valve, but upon reassembly it still intermittently loses power and idles like a sack of s...

 

Any info would be greatly appreciated

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It is caused by the breather pipe from the block.

 

As the engine wears the bores the engine begins to breathe more oil vapours. Chances are the intake has never been cleaned so you should probably clean the throttle body out to.

 

This is the reason why people run oil catch tanks.

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Cool nice one. So does the breather feed back into the manifold? I.e. the pipe attached to the side of the main manifold or the pipe at the side of the airbox? There was oil from the airflow sensor plate to the throttle body so I spent some time on that. The overrun (or at least that's what I think it is) valve was pretty full of it too, can these be cleaned out or is it best to bosh a new one in?

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^ If you confirm which engine you have it will be easier to explain.

 

On 16v there is a breather from the front of the block which has an additional pipe from the head which then goes into the side of the air box - this is often what causes the air filter to be caked in oil on one side. This pipe can be removed and the hole in the air box plugged. On my 16v golfs I then run the pipe into a catch tank (a pikey method was a 500ml coke bottle with some holes in it as the top opening is nearly exactly the same diameter as the breather pipe) which i then attached to the side of the radiator. Being a clear bottle you could see how much oil was being blown out of the sump - baring in mind my engine had over 200k on it there was a fair amount!!

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Good point,I should have cleared that up. It's a 1990 1.8 16v.So it'll be the one that is below,hooked to the airbox? I had to make sure I got the right one as the other one connects to what I understand is an idle control valve. I'm hitting the ground running with this one,learning fast...so many questions so little time! I think the oil has got into the overrun valve and shagged it...just guessing though. Yea it's got about 120k on the clock so it should be blowing by now

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Cheers for clarifying.

 

The over run can be removed and soaked in petrol to clean it out prior to refitting, the same goes for all the rubber pipework around the air box. When you refit it make sure you get a good seal, if the over run is lose then it can cause all sorts of odd running problems.

 

If you look at the front of the block just above the oil filter housing you will see the breather pipe from the block , follow it up to the just under the inlet manifold and then it goes into the side of the air box - this pipe is the trouble maker!!!

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