tmueller007

I am in need of some help. I was having my clutch replaced today at Kelly-Moss and they said that my oil pan gasket was leaking and needed to be replaced. Before they replace the gasket and rod bearings they wanted to do a leakdown test to see if the gasket failed due to blow-by. The leak down test yielded the following results:

2 cylinders = 8% each

2 cylinders = 10% each

My questions; should I replace the oil pan gasket (with the MySwiss retainers) and rod bearings (not worry about the top end for now)? Or, per these results, should I start looking into rings right now.

The car has 70k on it and I would like to add a fast951 kit on it but it will not be in the budget if I have to rebuild the top end now.

Finally, Kelly Moss did not give me a clear interpretation of the numbers. They said the engine appeared worn and close to the edge of necessary replacement. They also said the oil pan gasket may be a problem in future with this kind of blow by. Anyone else's experience/insight would be greatly appreciated.

Thanks,
Tyler Mueller

hosrom_951

8%+ does seem a bit high, the average leak should be in the 2%-4% range (more or less).

You can replace the ring, if the oil pan is off, but you would need to remove the cylinder head. There was a thread on this a few days ago, that describes just what is involved in replacing the rings.

A compression test would also tell you how healthy is the engine, on a fully warmed up engine and the throttle opened to max, the compression numbers should be 145psi-150psi across all cylinders.

tmueller007

Just spoke with Kelly-Moss and they are saying that they did the leak down test cold. But, they also said the results should be similar cold or hot. I need help; is it time to rebuild my top end?

Thanks,
Tyler

hosrom_951

Okay, i am not familiar with leak tests, nor have i carried one out. But what i do know and did actually do, is the compression test. This is where the engine must be warmed up, i would only logically makes sense to me for the engine to be warmed up when a leak test is carried out, due to the different tolerences between warm and cold engine.

Then again, i am not sure on that one.........

Flight_951

If you are going to add the Vitesse package in the future and run high boost and track the car, I would probably have the engine refreshed. If your car is consuming oil at a high rate and leaking from every gasket, I'd probably have the engine refreshed. If you plan to run moderate boost (16 or less) and it's a street car, I would personally do the pan gasket and bearings only right now. I had my engine rebuilt last year with leakdown between 10% and 60%, and it still drove pretty good although it consumed lots of oil. HTH

Toolmaster

Hang on here....

A compression test and a leakdown test differ in that the leak down test uses usually compressed air blown into the cyl... USUALLY you can tell where the leak is - by listening to the intake or exhaust sides of the equation (meaning valves and/or seats) or if it's going into the pan itself (meaning you hear NOTHING vale wise).

I'd ask Kelly-Moss where they heard the leak... If it's top end - do that. If it's bottom end - a ring job would be in order.

Hope that helps!