Engine – Oil Leaks – Rear Main Seal
Engine – Oil Leaks – Rear Main Seal
PURPOSE
The rear main seal is at the rear of the crankshaft, sealing the oil inside the engine and preventing it from leaking outside the rear of the crankshaft. The rear main seal is designed to last at least 100,000kms. Unfortunately, with a longitudinal motor, rear main seals may only last 60,000-80,000kms.
THINGS TO LOOK FOR
When checking for oil leaks it’s always good to check underneath the vehicle around the rear of the engine, making sure it is around the rear main seal and not around the top of the head. Sometimes a leaking rocket cover gasket may be the cause, if after replacing the rear main seal, there is still oil leaking. The best way to check any seal is to give the engine a complete steam clean but be very careful not to spray the steam around any ignition componentry or carburettor as this will affect the ignition system and also may cause a non start.
IS IT EXPENSIVE TO REPAIR?
The rear main seal itself costs around $15.00 but the labour can cost around $350.00 as it can be a full day’s job with some vehicles, because either the engine or the transmission has to come out, to replace the seal. Some rear main seals may cost $700.00 depending on the type of seal fitted. It may be a sealed unit or a wick seal. A wick seal is the worst seal because it is very difficult to fit and to ensure that there is no leaking.
Hi there,
I drive a 94 Hyundai Excel and had the head gasket replaced about a month ago. I’ve recently noticed that there appears to be an oil leak and am wondering if this could be a result of the work that was done? I don’t know much about that part of the car, evidently.
I had a lot of trouble getting the repairs done properly and if the oil leak is unrelated I’d rather go to a different mechanic, but if it’s the fault of the guys who did the head, I want them to fix it!
Also, I know it’s a tricky one given that I don’t know where the leak is coming from, but any idea what it would cost to repair, best/worst case scenario? Given the recent cost with the head I’m dreading another pricey job.
Thanks,
Kat, South Australia.
Kat,
To be sure if the leak is related, check the following
Take a look around the rocker cover gasket and around the head gasket, if you can see where the oil is leaking then that’s a start.
Now if its the rocker cover gasket then you will be happy to know it may just need the bolts retention.
If however this repair is unrelated then it maybe a rear main seal if this is so then it sounds expensive
Go to <a href="http://www.virtualmechanic.com.au/2009/09/general-inspection-rear-main-seal/"
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