Mazda CX-7 Stutter

mazda
cx-7

#1

In neutral/park the engine is smooth. In gear it stutters/fluctautes up and down significantly. Thought it could be fuel but it carried over to a new tank, plus, it is only in gear. Sensor? Turbo? Trans? Where do I even begin? Not ready to drop it off at a shop without some sort of clue what to expect.


#2

What year CX-7, how many miles? Any CEL’s (check engine lights)? When was the last time the plugs/wires were replaced? Any other history of possibly related problems?


#3

45,000 miles. 2nd owner, we’ve put about 4k on it. I haven’t done the plugs or wires, wondering if it was bad gas that only acts up when the turbo is engaged. Put in dry gas (in case there was moisture) and topped off w/ 94 octane to try to offset what I think was NOT 92 octane like advertised from another station. Keeping my fingers crossed for now.

No CEL’s, no other symptoms. Noticeable shift in certain situations, but consistent with what I’ve read about this car.


#4

If it’s an early build of the 07 model, then there were problems with the turbos in some of them. Other known problems are timing chain failure and a/c compressor. There’s also a reflash for the ECM I believe for the earlier models from the dealership as well, can’t remember though

http://finishlineperformance.com/store/pages.php?pageid=14
http://www.mcx7.com/showthread.php?t=396&highlight=2007+problems