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compression test


N9TE

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OK. Just did a compression test.

1. 135

2. 110

3. 140

4. 125

The variance is 22% and not the ideal <10% as is the accepted norm.

Engine ran great before and I'm assuming after.

Your thoughts?

If the engine wasn't fully warmed up before you did the check, I wouldn't worry at all.

However, a Peugeot mechanic told me that cylinder #2 is the one that usually blows after an overboost. :( I think if it was my car I would just drive it another 100k and not worry about it. :D

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If the engine wasn't fully warmed up before you did the check, I wouldn't worry at all.

However, a Peugeot mechanic told me that cylinder #2 is the one that usually blows after an overboost. :blink: I think if it was my car I would just drive it another 100k and not worry about it. :)

The engine hasn't been running in 5 months, so I'm pretty sure all the oil is off the control rings. I'm not going to sweat it. I've never run it into the red and I don't whup on the car that much.

Plus, I'm planning on getting a MotorVac done on it to try to deal with the carbon that surely is there.

I've had good running cars with worse numbers. Still, looks like I'll have to do a head if nothing else at some point.

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Hey Koll,

Doing compression tests on engines that haven't run is often just a guidline to make sure the engine isn't toast (IE when you're in a junk yard), so once you get it fired up do another test when fully warm, and if they're still low, drop a bit of oil into the cylinders and retake the compression test - and make sure the throttle plate is at WOT. With the oil then you know it's the head if the numbers stay the same, and if the numbers pick up then you know you're getting some leakage past the piston.

Hopefully after it's warm and you get the carbon treatment it'll all come back to within 10%.

As long as it's fairly close and they're over 100 psi the engine should still run quite well.

Rabin

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