ARGH.. weird idle

Okay… for a few days I’ve had a weird idle. It almost feels like one cylinder is weak. The car used to idle smooth, 3 days ago it started shaking and the exhaust makes kind of a “putt putt putt putt putt” sound (no leaks, this is from the muffler). If I hold the throttle around ~1500 or so it fluctuates by about 100-200 rpm even though my foot isn’t moving. Any higher and it runs strong. It nearly stalls when the a/c compressor engages too - never did this before.
Changed the plugs yesterday, and it had been running /really/ lean - 1 plug was pretty heavily damaged. I was thinking burnt valve, but I swung it by my mechanic’s today and he blames it on engine mounts of all things (he didn’t do a compression test though), and my throttle cable being too tight.

I’ve changed O2, cap, rotor, plugs, fuel filter, wires…

Think valves being out of adjustment could cause this?

I would check to make sure that you do not have any vaccum leaks. Sounds like something has come loose or a hose has a leak. You can try to find it by spraying throttle cleaner around vac. hose connections. If the idle goes up, you found the leak.

It sounds like maybe one cylender is dead or maybe weak…maybe a compression test??

sears was kind enough to “rent” me a compression tester. lol i love return policies. even though i work in retail

1 cylinder was indeed weak… compression test showed something like 183/90/182/183

… stuck exhaust valve =/

oddly… after I changed the oil it cleared up the next day :shrug:

I’m lucky :stuck_out_tongue:

Same exact thing with my car, and I need an oil change real bad. So maybe that is the problem?