I have looked around the site, but haven't found exactly what I'm looking for.  My 96' Tracker has lost power and when it starts getting warmed up the engine idles rough and starts sounding something like a mini air compressor near the firewall.  Last time I checked the oil it didn't look milky.  Any ideas of what this might be?  Head gasket, intake or maybe exhaust leak??

Thanks,

ERock

Have you done a compression test?

Do you see any fluids leaking from the block?

Make sure your EGR valve didn't fall apart. (there is a plug that is pressed into the body of it that if it fell out  would cause these sort of problems.  you can fine the egr on the passenger side of the motor (US) on the back towards the firewall. you may have to pull the battery to get to it.
it is held on by two bolts.  if it is loose that would cause this too.  check for vaccum leaks also

I haven't done a compression test, I don't see any fluids leaking.  How much is the guage for the compression test?  What is the right compression for the track/kick? 150psi?

I'll check the egr valve tonight.

What's the best way to check for vaccum leaks?

It was the EGR valve... Thanks for the help

One bolt was loose and the other one was gone
Should I use anything on the threads when I put the new bolts in?

I always use a high temperature grease on all bolts (except the head bolts). While the EGR is half off you might as well remove it and give everything a good clean out. If you look back over a few recent threads you will see that a bit of preventative maintenance could be well worth while.