Sorry for the newbie-type question but I couldn't find my answer by searching the archives. What is 'good' compression? I have found thread stating compression of 6.0-7.0 needs rebuilding, but I can't find anything stating what compression is acceptable on an original engine. The dealer selling the car says the compression is 8.3. Is this OK?

 

8.3 is awesome.


7.0s = good/ok

6.0s = start looking for a rebuild.

5.0s = ouchy

4.0's = pwned

3.0s = why do i own an fd

2.0s = i like cabbage

 

Make sure the dealer gives you a printout of the readings on each rotor face and readings in the front and rear housing. For instance, readings of 6.2, 6.3 and 6.6 in the front housing with 8.3, 8.5 and 8.8 in the rear could be a bad sign. Make sure they quote you both housings and their corresponding face readings.

Some disparity between housings is acceptable, for instance 7.0s in one housing and 8.0s in the other, but all three numbers should be fairly close and the difference from front to back or vice versa should NOT be drastic.

 

yep. dealer is just looking to sell the car. unless they do it in front of you and put it on paper, don't believe them. once you walk out and have the compression checked by an impartial party and find out they lied, it will be too late.