'85 GSL 302

What would cause low compression in a 13B-T other than worn apex seals?

I'm thinking about getting a car but It may have compression problems and I really don't want to buy a car that's going to crap out on me soon after. Are there things that could cause low compression that aren't serious enough to worry in a rotory?

Project84

The apex seals, side seals, and corner seals (all of which are on the rotor) are what form the compression. To replace the seals, you have to take the motor out, open it up, take the rotor out and replace the seal. It can't be done with the motor in the car.

Fingers

Low compression? almost dead motor? Has it been sitting for a while? High/low mileage?

If it's on its last leg anyway, try the ATF trick to clean up the carbon. do NOT do it on a perfectly working motor because you may very well kill it.

MURX

Do you know what the numbers are? Another possibility is if you live in a higher altitude region, you # will be lower.

hypntyz7

Since compression measures the ability of the engine to seal and compress air, by definition low compression is equivalent to internal wear. Since the rotary uses apex seals and a rotorhousing surface as it's *primary* compression source, then yes, low compression means worn rotorhousings and apex seals. Plain and simple.