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MG MGA - Oil leak

I've started to restore a 1960 MGA and it's a learning process. I'm not familiar with the car but managed to get it back into running condition and back on the road. Unfortunately, the engine is now leaking oil quite badly when it is running. The leak seems to be coming out of a small valve or plug that's screwed into the block on the right side of the engine, just above the starter and just behind the distributor. The plug appears to have a little lever valve on it but it's not connected to a hose or anything. The valve/plug is very corroded (looks like blue oxidized copper) and I believe it's just falling apart and causing the leak. What is this valve/plug for and is it common for it to rust out? I haven't tried to remove it yet until I understand its purpose and know if I can get a replacement.
R Lewis

It sounds like that is where the feed line to your oil pressure gauge connects. Are you getting a reading for oil pressure on your gauge?
S E Bryan

Coolat drain petcock? Look here. There are 3 things, from the rear, Oil line to filter oil line to gauge and coolant drain.
http://www.mgaguru.com/mgtech/care/csm/mg291.pdf
R J Brown

Yes, I'm getting pressure at the oil gauge (50-70 lbs when driving). This little plug/valve is just below where the feed line for the oil pressure guage connects into the block. The feed line for the oil cooler comes into the block in this same area as well. I'll see if I can get a picture.
R Lewis

That's it! It's the cylinder block drain tap. Thanks! Now I need to figure out where to find a replacement.
R Lewis

A pipe thread plug would make non stock repair that would allow you to drive the car.
R J Brown

You would not get oil leaking from the coolant drain tap. It still sounds like the fitting for the oil pressure gauge is leaking. The oil then runs down and drips off the coolant tap.


Mick
M F Anderson

I was curious about oil coming from the coolant tap as well. Didn't quite make sense so I had to check it closer. You're right, it's the fitting for the oil pressure gauge that's leaking. I wrapped a paper towel around the base of the oil gauge fitting and that's where the oil's coming from. It's running around the coolant tap which makes it appear to come from there. I should have done a bit more detective work to begin with.
Thanks for the feedback!
R Lewis

There are two parts to the oil pressure gauge take-off, both of which could leak. There is an adaptor that screws into the block and has a washer then there is the oil pipe itself with its gland nut and an olive on the pipe. Make sure that the adaptor is tight in the block, there is a tendency for the adaptor to screw out of the block when trying to undo the pipe gland nut. Not easy to get to, but try to hold the adaptor with an open end spanner while you undo the gland.
Lindsay Sampford

This thread was discussed on 07/09/2009

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This thread is from the archive. The Live MG MGA BBS is active now.