Mechanics

RUNNING ROUGH

2004 Mazda MPV • 6 cylinder FWD Automatic • 125 miles

I have a 2004 Mazda mpv. The problem I'm having is that the car****** at times. Sometimes when driving and sometimes sitting still like at traffic lights. It has the resemblance of a vacuum problem. It gets worse when ac is turned on. Also when it"s changing gears the tach will rev higher. Has not had a check engine light come on. Any help would be great. Thanks, Chris
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Brake Light
June 22, 2011.



This engine is known for coil issues. And they are NOT cheap. Best way to diagnose is by part substitution. Ie; replace them with known good coils. Bench testing coils, and/or ignition leads is not a sure-fire way to tell if they are faulty.

Tiny
Sixpack Subaru
Jun 22, 2011.
Have the spark plugs checked as well.

As to the engine revving higher, check the transmission fluid level.

KHLow2008
Jun 22, 2011.
Great advice guys. I replaced the ignition coils and so far so good. Removing and replacing plenum assembly was tough but was managable. This seems to have corrected the tach revving higher as well. Thanks Again, Chris

Tiny
Brake Light
Jul 4, 2011.