2002 996 leak down test cold????

72_wagon · 06-17-2012, 06:36 AM

Long story short i have a 2002 996 with a blown engine and have a another that is on a engine stand and need to test it to see if has a problem. I know that it is recommended that you preform this test warm but that is not a option. I will also be doing a compression test..

As i have no history on the engine and it has a heavy intermix.... like so heavy that i dont think it can be a cracked head...also the crank case didn't intermix.. I tested the oil cooler and it didn't leak when tested with pressure on the coolant side.(tested at 60 psi) but i tested the oil side with 90 psi it leaked to the coolant side.. also when i removed the cooler from the engine the rear coolant port the large one closest the flywheel was full of non mixed oil and underneath it was intermixed oil..

So before i change the oil cooler and install engine i would like to verify that the engine doesn't have a bigger problem.. or before i tear into it and rebuild a top-end for no reason..

So the question is will a cracked head show up on a cold compression test and leak down test?

Thanx for any input if you have preformed these tests before

Marv,

Travis84 · 08:08 AM

Marv, when these heads crack, it is usually around the spark plug tube hole. If you can, pressure test the cooling system of the engine. This may be difficult as there would be quite alot of places that need to seal, but you can see the leak with the cam covers off. I recently did one that the passenger side head was cracked, but more often than not, its the drivers side. Another option is to pull the head and have your machine shop pressure test it. Good luck. Let us know what you find.

Travis84 · 06-18-2012, 06:14 AM

72_wagon · 06-18-2012, 06:31 AM

Thanx for the reply Travis... I'm really don't want to tear into the engine unless I found out that I need to. I will try to cap off the outlet and pressure each cyl. And see what happens.. I'm hopping that the leak down test will tell me what's going on....

alfa11 · alfa11's Garage

Quote:

Originally Posted by 72_wagon

Thanx for the reply Travis... I'm really don't want to tear into the engine unless I found out that I need to. I will try to cap off the outlet and pressure each cyl. And see what happens.. I'm hopping that the leak down test will tell me what's going on....

You might pull the valve covers off and spray the suspect areas on the heads with soapy water to check for bubble formations when you do the pressure test.

BYprodriver · BYprodriver's Garage

Quote:

Originally Posted by alfa11

You might pull the valve covers off and spray the suspect areas on the heads with soapy water to check for bubble formations when you do the pressure test.

After locking engine at TDC, (should be at TDC already to relieve pressure on valvesprings) & installing camshaft locking tools.

72_wagon · 06-19-2012, 05:42 PM

I'm not going to open engine..I did a compression check and all cylinders were with in 5 psi of each other. I didn't get to do a leak down but pressured the cylinders and they all were holding good and one hissed slightly from intake valves... Poured in some mystery oil and one valve held all the oil and the other leaked half way... Just a little dirty. Cleaned all runner's and it looks like the oil cooler has to be the culprit of all the oil in the coolant system...