Compression Test...Leak-Down Test

[hgray14]

I just ran a compression test on my GF's '93 850 GLT.

It read like this: 195, 205, 215, 195, 205

(the number 3 got oil in so I am guessing that is what gave the high reading.)

With numbers so consistant is there any point in doing a leak-down test? I know that a leak-down gives you further info that you don't get from a compression test but it is also a much bigger hassle and at 140K it seems to be running great.

[mojojo]

For good numbers, allow 10% between cylinders.

From what it sounds, the leak down is not needed... but neither was the compression test?

Your call.

[hgray14]

For good numbers, allow 10% between cylinders.

From what it sounds, the leak down is not needed... but neither was the compression test?

Your call.

I usually run a compression test if I have the plugs out since it only adds a few minutes to the tune-up. But with such good numbers I figured a leak-down wasn't necessary but wanted to double check.

Now, on the T-5R with 200K that has sat in my driveway for 2 years after sitting in the previous owner's yard for 3 years I am going to run both tests prior to deciding if I want to pay the DMV fees, replace the steering rack, tune the engine, change the oil, get new tires, brakes and probably struts and pay for SMOG and start driving the thing. When I checked the compression two years ago it was in good shape but I want to do everything I can to reduce the risk that I spend on this money and still end up with a lemon on my hands.

[TRACStar]

Not a bad idea when the plugs are out. And great numbers for the mileage.

I wouldn't bother with a leakdown test.

[hgray14]

Not a bad idea when the plugs are out. And great numbers for the mileage.

I wouldn't bother with a leakdown test.

Yes, that is what I thought too. I have never done one on a N/A engine so the first number really threw me. I was used to the lower Turbo compression numbers but once I looked it up it made more sense.

The amazing thing was the shape of the plugs. I am surprised they still worked. They were burned/corroded/etc down to a gap of somewhere around .060 instead of the .028 they should be. It was amazing and the car is running great now. I know what a turbo is suppose to run like but since I rarely drive her N/A car I just assumed it was super guttless and that was the norm. It is still guttless but at least it runs nice an smooth now. Once I fix the exhaust leak and get a new O2 sensor I bet things will get even better.