mr flibble

Ok guys,

MY00 had idling problem, idling just wouldn't settle. Took it to dealers, they diagnosed air flow sensor after running diags. They replaced the sensor, and tested, said everything was fine. I got the car back and at the first junction i stopped at once the engine had warmed up, I noticed how the car idle was now constant but felt rather lumpy and engine note slightly deeper. Car runs fine on and off boost.

Is lumpy idle normal, certainly more movement inside the car when sat in traffic?

M.

Bob Rawle

did they do an ecu reset if not the disconnect battery for 20mins, as the easy way.

if the maf was on the way out it would run the car leaner now it will be fueling differntly and the learning will have to adjust. its not normal for the engine to run like that, assume you mean the engine is shaking on its mounts, check that all the plug leads are in the coil pack properly.

bob

mr flibble

bob,

Its not a big shake, i am just aware more that i have a flat four under the bonnet if you know what i mean. I'll check above tomorrow.

Interesting that you say it should be running leaner with a MAF fault. They told me the car was running too rich, and showed me a print out from the diags. I had noticed an increase in fuel consumption since the erratic idling started, and even though the rpm needle sits in the exact same place (2 notches below 1000rpm), previous to the MAF replacement, the car always sounded as though it was running too fast.

M

mr flibble

...........oh yeah forgot to say, exhaust seems to pop a bit more now when coming off the gas to change up or down.

Bob Rawle

right, so taking that on board the scenario could be "was too rich" therefore smoother idle as the ecu was not having to alternate the fueling so much, either way. If it was rich then the maf was probably virtually stuffed so hopefully it was not like that for too long ?

bob

mr flibble

car was never lumpy from day 1 of ownership, although it did have usual flat spot between 2 - 3,000 rpm. 46000 miles later idling went up the spout, i noticed it happened within 2 weeks of waiting for its service. I backed off driving it hard, and the dealer was certainly keen to get the car back in asap once they diagnosed the problem.

Dealer in question is fairly local to yourself Bob, just down the road in cirencester. I have had no problems in the past with these guys always get good service. Just checking that lumpy idle is normal\incorrect before i contact them.

thanks

M.

Dark Blue Mark

Sounds like they reset the ECU when they changed the MAF and revealed another fault, which the ECU had learned around. It may be the lambda which was at fault and resetting the ECU has cancelled the learning...

MB