my compression is low on my s5 turbo motor. the mazda dealership says i need a new motor. can i raise compression? or should i get it rebuilt?

 

You will need to get the engine rebuilt or find a good used motor with low miles on it & install it. There are deals to be had but you will need to look around.
Good luck with your project!

 

Did they give you the compression numbers? If so post them here.

I would suggest that you do yourself a favor and have an independent rotary shop do another compression test. It will cost you a few bucks but you want to make sure you need an engine rebuild or replacement before spending the several thousand dollars that will cost.

Or you can do a basic compression test yourself. Go to Aaron Cakes site for instructions on how to do a simple test:
http://www.aaroncake.net/rx-7/blown.htm

 

Low compression could be caused by carbon buildup on the apex seals. Try running a can of Seafoam through the gas tank, then get a second opinion on the compression. Good luck...



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here are the numbers: R-1: 5.8, 6.1, 5.6 at 260rpms. R-2: 5.9, 6.1, 6.2 at 261rpms. i also tried sea foam, the car wouldnt start back up after i put it in the gas, i had about 10 gallons of gas in the tank and while it was turning over white smoke was coming from the exhaust.

 

Those numbers indicate that your engine is a bit tired but it should still run fairly well. No obvious indication of a seal problem, just general wear and tear. You might want to start saving for a rebuild or replacement, however, but it won't hurt to keep driving the car. Apparently, the dealer is looking for work.

Perhaps you put too much sea foam in the tank? Try filling the tank and cleaning or replacing the plugs before attempting to start again. Then do a deflooding routine. With those compression numbers, you need to ensure that you don't shut the engine down cold to avoid flooding.