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View Full Version : hesistation from a rough idle



rob101
01-10-2006, 06:17 AM
just a quick query, I have a rough idle, so rough it will shake the car, when it gets this bad it also seems to hesitate to rev from idle. but once it revs all is well, I assume this is the Oxygen sensor playing up and making it overly rich at idle, is it possible it could be an AFM problem. Apart from the rough idle when the car is warmed up, the car seems to rev etc. pretty well.

t_marat
01-10-2006, 02:47 PM
I have the same issue. People were saying to check the vacum by spraying carb cleaner.

dacoyote
01-10-2006, 03:05 PM
Way off the wall.. but quick to check....

Make sure you value cover gasket isn't leaking.....

the plugs will short out and make a miss... are you missing at high load... it can be hard to tell on the M50

rob101
01-10-2006, 04:19 PM
i replaced the valve cover gasket only recently, hmmm vacuum leaks, son of a b#$%$. Just to clarify, i meant Rough idle even after the engine has warmed up, and usually worse the warmer the engine is. which is why i suspect oxygen sensor. but apart from idling the engine runs fine it makes a bit of rattle etc. above 3k rpm but i think it is fuel injectors (sounds like e46 m3 apparently).