924Board.org

[TajMan]

Hey guys. I used my '87 924 S as a daily for some time this year, it always ran pretty awesome like a *race motor! I believe I've put about 9K miles on it myself, Its got 137K miles on it now.

The car has an aftermarket exhaust from the header back, NO cat-converter, and a bad exhaust leak before the race muffler.. because of poor exhaust design and contact with the driver's side rear axle when the suspension compresses completely! Axle wore a hole right through the 3" exhaust pipe! Yes, its always been loud.

I've run synthetic oil, even some zinc additive to oil sometimes, premium gas.


More recently, I had the car parked in my new shop for a few weeks. When I went and started it, it ran like crap! Totally rough/missing/not smooth anymore.
I've been distraught for literally months now.

Finally got to some work on it, pulled the plugs and did a cold compression check. Plugs all looked ok. At this point I started to be suspicious.. maybe just old bad plug wires caused this issue, that would be great.

Compression numbers:
#1: 120
#2: 120
#3: 115
#4: 150 !!

Well shoot.... what do you 2.5 engine experts have to say about these results?

At this point I have Bosch spark plug wires coming, I will install and see how the motor runs. If it fixes issue great, I'll do another proper warmed-up compression check later.

I also have a new universal hi-flow cat-converter I need to get welded in, and somehow I will get exhaust modified and hole patched up above the rear axle before muffler.

basically one way or the other, I need to sell this car now unfortunately! New shop space, too many cars and this is one that has to go.
Its a pretty clean and original 924 S example.
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'87 924 S

[TajMan]

I'd just like to know more what 'average' used compression numbers do on these engines.
Is #4 being high normal?
Is it normal to show these tendencies cold, but maybe a later warmed-up check will bring the other three up higher so all 4 are in a closer range without as much deviation?
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'87 924 S

[Rasta Monsta]

Should be 150-160.

Squirt oil in and re-test. If numbers come up, you have worn rings.
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Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3