Leak down tester

[cmvasquez]

Hey guys, been a while since I made a post so I apologize if this is in the wrong section. Anyone out there willing to help a fellow petrohead do a leak down test on my 1988 911 cab. I am going through about 3 Qts a month and I would like to have a better idea on what's going on. I checked the car for leaks both while cool and hot and I cannot see any visual leaks besides what I believe to be a small leak coming out of the valve cover gasket. I am replacing the gasket seals and adjusting the valves while in there but if anyone is around to help out/lend me a leak down tester it would be greatly appreciated since I really doubt 3 or 4 qts are coming out a month of solely the valve cover gasket. Also while I have the covers off is there anything else I should be checking while I am in there that could contribute to this oil loss.

I should mention the car has 188,000 miles on the engine but seems to run great. I have never had a problem with the performance of the engine and have not noticed any change in the way it drives since I got the vehicle about 8 years ago. It has always has a slight engine consumption problem but at first it was about 1 to 2 qts a month. Now it's doubled

As always any suggestions would be appreciated.

Cheers gents.

[pete3799]

Perhaps if you mention where you are you might have an easier time finding someone local to help you.
3 qts. a month? How many miles? Does it smoke on deceleration?

[cmvasquez]

Sorry about that guys. I am in the la region in the woodland hills valley. 188,000 miles are on the engine and it will occasionally blow smoke but it's mainly when the car is warming up and at idle at a stop light. I drive the car through the canyons a few times a week and I haven't seen any smoke at higher rpms but my buddy said he can see my car smoke a little when I downshifting hard every once in a while. The smoke is never a really heavy set of smoke but rather very faint. Like I said I notice it most when I'm idling at a stop light or in the garage before taking off but that could very well be because I have not really payed a lot of attention upon deceleration. I will check it out today and post what I notice.

Thx, cheers

[911pcars]

Two main areas that allow excessive oil consumption:
Worn valve guides/valve stem seals
Worn/stuck/broken oil control rings (piston)

A common reference point is the no. of quarts consumed/1000 miles or thereabouts. 1 qt in a Porsche is normal. More than that indicates something else.

A leak down test verifies adequate compression seal in each cylinder. It won't pinpoint oil leakage in these two areas.

Pull the spark plugs and inspect. Excess oil consumption will show up with excess oil/carbon deposits on the tip.

Have a helper follow you and observe the exhaust as you drive. If excess oil is being burned, it will show up as blueish smoke from the exhaust system, especially during acceleration and deceleration.

Hope this helps,
Sherwood

[2.70Racer]

Run a compression check on your engine first. A leakdown test is done to determine where an engine is losing compression. (rings or valves)
A leakdown test further will not show the condition of the valve guides or seals.