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Classic Car Service
Classic Car Service, Dealership Svc. Mgr.
Category: Car
Satisfied Customers: 4848
Experience:  Over 30 years experience in the automotive field
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I have a persistent oil leak that the mechanic can't seem to

Customer Question

Hello. I have a persistent oil leak that the mechanic can't seem to fix. I am wondering if there are no visible oil leaks is it possible that the oil can get leaked into the exhaust system? Regards, Brook
Submitted: 2 years ago.
Category: Car
Expert:  Classic Car Service replied 2 years ago.

Hello. Welcome to Just Answer Please allow me to assist you. When you are speaking of an oil leak, are you seeing oil leaking onto the ground under the vehicle, or are you experiencing oil usage and have to add oil often? Please clarify Thanks

Customer: replied 1 year ago.
I am losing about one litre per month. Recently I looked under the engine and I can now see dripping points on the sump. I have taken it to the mechanic now 3 or 4 times and he keeps fixing it but then the oil still keeps leaking. This is why I was wondering if the mechanic maybe missing something?
Expert:  Classic Car Service replied 1 year ago.

It is possible that there is internal pressure inside the engine that is causing the oil to be forced out past the seals or gaskets. This is caused by a condition known as 'blow by', where the piston rings allow combustion pressure to be pushed into the crankcase/oil pan area. The recommendation here would be to have a compression test performed by your mechanic. If the compression is low, the blow by condition will exist. This would require a new set of piston rings.