View Full Version : 2001 Mitsubishi Diamante runs rough

11-12-2009, 09:24 PM
Hello, my car is running real rough while in neutral and while driving. Its rough when I put in into park and reverse. Just wondering if anyone knows about this car. Car has 68k on it. Thanks

11-12-2009, 11:18 PM
Last time you replaced your plugs/wires/coils?

11-13-2009, 02:56 PM
Im not sure I never have only had car few months... But this thing runs real rough you know think its something more serious

11-13-2009, 03:26 PM
Basic tune-up would be the place to start. If it doesn't help any, atleast you know where you stand in your routine maintenance.

11-23-2009, 11:18 PM
Is the check engine light on if so have someone scan it and get the codes. I would start with a tune up as well or could possibly be a vacuum leak. Open the hood listen to see if you hear hissing. You would be surprised how much a small vacuum leak can effect the idling.

I Like Waffle
11-25-2009, 12:10 PM
Vacuum leak. On those small import **** motors it can really hurt them as alot of **** is controlled through vacuum pressure.

11-25-2009, 07:44 PM
I would have to agree with the two gentlemen above. Good luck.

Rich B
11-25-2009, 07:50 PM
I had a rough idle on my 01 Eclipse for a year after I bought used in 2007, checked the vac lines, replaced spark plugs (with Iridium), cleaned the MAS, cleaned the throttle body, and nothing seemed to help.

I finally gave up and was considering new coil packs when I looked at the plug wires real closely and I saw a tiny hairline cracks on two plug boots.

Replaced those two wires (at $18 ea...what a ripoff!) and the rough idle is gone.