Help.... I have a 97 maxima with 155,000 miles on it. I did a compression check after the car was running and warm for a while and got a reading of 130 on the first two cylinders. I want to put NOS on my car if possible. What should I do ??? Any suggestions would be appreciated !!!

Thanks,

 

i believe 130 is really low.

did you see if it was the rings that were messed up or the head gasket.

if you have a haynes manual they will tell you in there how to see if the problem is a head gasket or the cylinder rings.

 

Standard Compression pressure is 185 psi, minimum is 142 and difference between cylinders is 14. My engine is actually between 190 and 200 on all cylinders.

I wouldn't consider nitrous with 130.

 

What would be the minimum you would suggest ???

Thanks

 

dude i would fix that motor off your first before worrying about nitrous. i can not believe a motor with compression test below factory specs with survive on nitrous.

 

First of all, you need to have all the spark plugs removed, and you need to test ALL of the cylinders. Make sure your engine is at operating temperature, and make sure you crank it over at least 7-8 times on each cylinder. Do you have a haynes or chiltons manual? If not, pick yourself up one of those first. Oh yeah, don't run nitrous if your at 130, like everyone else already said. Good luck.

 

Regarding plug reading and compression tests, isn't it generally a bad thing to pull plugs or thread anything while the engine is hot?
-hype

 

Well when the engine is warm, it does cause everything to expand, but this is the way it must be done to get an accurate reading. Same thing with checking your spark plugs after a nitrous run, the best way is to shut the car off, let it coast to the side, and then pull the plugs and check them for signs of detonation. I just put anti-sieze on the threads and Ive never had a problem...

 

OK i will check it on all cylinders. If it still is 130 what can i do to get it back up to spec.

Thanks

 

you have to find out what the problem is. haynes will tell you how to check if its the rings or a head gasket or a bad valve to give you an idea of where to begin. just get a haynes manual and read up on the compression check section.

 

OK I will do that.... I will post back when I find out some more info.

Thanks Again