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SVCamelot 08-06-2022 12:10 PM

Diagnosing a slow oil leak
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Hi all!

I'm new to the forum and very grateful for the community.

I have an A4 in my 1972 Morgan 30' that I have owned for two years. Recently I have found small amounts of oil in my bilge and I believe it is coming from somewhere on the port side of the engine.

I have identified two places that I suspect. One area is a bolt (one of two) that holds a flat panel that is inboard of the throttle lever (picture provided). It looks like oil has been coming out past that bolt and dripping down the side.

The other place is, when I place my finger below the throttle lever (forward of the electronic fuel pump), there is a long skinny tube running from top to bottom that seems to have oil running down it.

Two seasons ago I had to pull the engine and replace the oil seal at the thrust bearing. I have since checked below that bearing and do not feel or see any oil escaping there. So I think that is ruled out.

I would appreciate any tips you may have!

SVCamelot 08-06-2022 12:13 PM

One more photo
1 Attachment(s)
One more photo showing oil collecting on port side. Photo is from an overhead view looking down. This is from winter storage (I know I should have replaced the oil prior to storage, but have changed it since this photo was taken).

Dave Neptune 08-06-2022 01:27 PM

First welcome to the MMI Forum.

The plate under the manifold is the cover for the valve train. First check to see if there is a lock washer on the bolt, if so replace with a washer or a "star lock" washer. If that does not stop the leak it is time for a new gasket probably.

The small tube is called a scavenge tube a safety devise. just tighten the fittings. It is just a pieces of 1/8" copper tubing with compression fittings. It collects fuel droplets that collect in the carb and allows them to be sucked into the intake manifold so they don't leak out of the carb.

Dave Neptune :cool:

SVCamelot 08-07-2022 08:02 AM

Hi Dave,

Thanks for your reply! I don’t think there is a washer of any kind on the bolts that hold on the valve cover. If I am to replace the gasket, should I remove those bolts to take off the cover and then replace the gasket inside?

Dave Neptune 08-07-2022 09:30 AM

Yes, those bolts hold the plate on that the gasket seals.

Dave Neptune :cool:

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