Oil Leak 1995 STS

[RonDav]

My 1995 STS with 107,000 has had a crank case gasket leak for sometime now. It becoming a little worse over time. The dealer states that they are reluctant to work this problem in older cars. Sometimes about aluminum engine and the bolts not fiiting properly and futher problems with the water pump whcih has been replace a few years back. I have tried an STP oil additive to stop engine oil leaks and to rejuvenate worn gaskets. So far nothing has improved. It has only been a few hundred miles since adding the additive.

Does anyone out there have any advice or know of a good reasonable mechanic in the Washington, DC metro area that can address this problem.

Thanking you in advance for your help.

RonDav

[TDK]

RonDav,

1. Are you (or someone else who got under the car recently) certain it is a crankcase leak? There can be a number of other causes (and of course, most of them drip down...)

2. Search on "half case" oil leak, there is a lot available.

If it is the "half case" leak, then (at least from what I understand) it will not become a gusher. It is not on a oil-pressurized portion of the engine, but rather "splashes out" a few drops now and then when operating. <_<

The seal replacement is not cheap, but was documented recently with pics. There is a new seal design that has greatly alleviated the problem.

Sorry, don't know about shops in the DC area.

Good Luck

[jhall]

RonDav

I don't think the stop leak additives will have much impact since these seals are silicone-based and quite resistant to additional swelling beyond what normally occurs from engine oil exposure.

If possible, try to clean the engine at the valve cover and split case areas (yes, this will be a tough job, but may pay off!). Run the engine for a while and see if the leak area(s) show up.

If it's hard to tell where the leaks are occuring, clean again as needed and apply some spray-on foot powder to the suspected areas. Run the engine again and watch for color change as the oil contacts the powder.

Good luck!

[JimD]

Are you 100% certain you are seeing an engine oil leak? It "could be / might be" power steering fluid that is adding to and compounding a very slight half case leak.

Have you been adding PS fluid? I had a pin hole in the high pressure PS hose that spayed fluid on the front crankshaft cover which dripped down and was blown all over the RH bottom of the engine. Leaks only with steering input; hard to locate.

Also, the crankshaft position sensor O rings can very slowly leak and drip down to be moved to other places by road draft.

Do not assume a worse case situation; eliminate the easy-to-fix items first.

[KenD]

I had a small leak also and it came from using an aftermarket oil filter. I changed it to AC Delco and the leak went away.

Probably won't help your situation, but I thought I had a half case seal leak also until I changed the filter.

[Scotty]

Someone recently commented on being able to get a full turn on his pan bolts, don't over torque them but try retorquing your pan bolts to the proper spec, I plan too...