1998 Chevrolet Monte Carlo Oil Leaks

NATEANDCHASE2007

MEMBER
1998 CHEVROLET MONTE CARLO
265,000 MILES

Hello,

After taking my Monte Carlo Z34 (3800 Series II engine) to the shop to be checked for where the oil leaks are coming from they informed me that the front and rear main seals, the oil pan gasket, and rear valve cover gasket were leaking. They told me they didn't think it would be worth fixing because it would probably start leaking again down the road. He had said I could possibly be getting blow by which is causing the leaks that I have. The engine was overhauled in January of last year where they replaced the rod end bearings, the heads rebuilt and all of the gaskets associated with getting to them. What is the best way to check if I am getting blow by or what is actually causing the leaks I have? I would like to confirm that I am getting blow by if that is in fact the problem. If I'm not I would like to be able to figure out what is causing the leaks.

Thanks in advance,

Nathaniel Barnes

1 Reply

CARADIODOC

MECHANIC
33,864 POSTS

The test that would be most informative is called a cylinder leakage test. You pump compressed air into each cylinder through the tester and it measures the percent of leakage. You also listen in four places to identify the cause of the leakage. For excessive blowby you will hear the air escaping from the oil fill cap or dip stick tube.

You can also inject white, non-toxic smoke under two pounds of pressure from a smoke machine into the dip stick tube, then watch for where it sneaks out. If the leak is related to something where the oil is not under pressure, like the oil pan and valve covers, you'll be able to see the smoke escaping.