My car has been shootin out alot of whitish grey smoke whenever I start it up, and on ocasion when I punch it. One of my buddies said it could be the piston rings? So how can I tell if they are bad are not, and will it hurt performance at all?

 

If it's whitish smoke its probably antifreeze, which means head gasket. But to check the rings you need to do a leak down test. It's not hat hard, you just need a leak down gauge and a compressor.

 

you can also pull the oil dipstick out while engine is running,if air is puffing out you have blowby.
pull the oil fill cap off with engine running it will do the same as above..
generally if rings are bad you will experience more smoke out the pipes than just start up.you can do a compression test as well.....

 

Yeah, sorry. I meant compression test, but leak down was on my mind for some reason. A leak down test is really to check the valves.

 

You'll also notice that youre having to add oil to the motor alot.

 

A leakdown test would actually be the best test to do.

 

Well if it buring coolent, would that be a head gasket? And where can I get one of those tests done at?

 

You can do a compression test with a simple compression testing gauge set from autozone or advance. Just take out a spark plug, screw the test gauge fitting in, pull your fuel injector fuses and crank the engine. All of the cyls should be well above 100 psi, I think, and they should all be within about 10psi of each other.

I think you can do the leakdown test almost the same way.. you just hook up an air compressor (somewhere near 100psi) to the fitting thats already in the spark plug hole. I haven't done this yet (I've gotta do it this week), but I think you have to have the cyl you're testing at TDC on the compression stroke (so that both valves are closed).. You'll probably also want to have your tranny in 6th if you have a manual, so that the engine won't spin (And, keep the injector fuses out so that it won't start if you forget to put it in 6th and it starts to spin!) Then, I think you just listen to see if you hear too mcuh pressure leaking out of the cyl or not. I think there will always be a little bit leaking, even on good engines. I think you can test for head gasket leak by opening the radiator cap and seeing if coolant sprays out. You should be able to hear through the valve covers if its the valves leaking (If so, should be an indication of valve seals.) I think there are probably other things you can listen for too, but I'm not that experienced with the whole thing.

Good luck with this, and let us know what you find out! I hope its valve seals and not head gasket or worse, piston rings!