madsedan

Just did my own compression check for a guy coming to buy my car and got the above numbers, and I took a picture with my digicam of each one in case he wanted to see them.
I was happy with those numbers, are those good for a cheapish compression check device?
I guess the important thing is that they are all about the same, right?

This guy's getting a wicked deal for $4k...

madsedan

I just downloaded the pics I took after cranking each cylinder with the gas pedal floored and they are all right at or above 130, maybe 130-132, awesome!

Sam Lin

This is cold or hot?

Sam

madsedan

Car was warm, about 10 minutes after I drove home from work.
Is that the right answer?

awilson40

seems a little low on warm car. But as long as it was even. How did you do the test??
You should have the throttle wide open and let the engine crank until the gauge maxs out.
It should max out in 3 -4 revolutions.

madsedan

Thats exactly what I did, floored the gas pedal and cranked it till max, it was a cheapo $50 kit, may be why the numbers were a little low but others on here have gotten numbers around 130-135 on their cars as well so it must not be too bad.
The car just left with its new owner so I'm back to BMW M3s.

hosrom_951

I got 150 on all 4 My specialist did the whole process infront of me, took few mins and car was warm......

User 41221

hosrom, why are you not smiling? 150 on all four is a good number, and a good bit better than madsedans. Madsedan, having them register evenly across the board is more important than getting higher numbers, could be that your cheap tester is just reading low.

Regards,

RPG951S

I agree, consistant numbers are more important than the actual values.
I think that there is too much variation in the 'inexpensive' compression gauges to say that 130 is too low - it's most likely the gauge.

BTW - my turboS was ~150 across all four, cold, with throttle cracked open with a cheapo $30 compression gauge.

hosrom_951

sh944: I have this thing when i type, i usually mean another smiling now just for you

I gave a 'confused' face because his readings were pretty low for what i got (and most of everyone else's)