dannewvillage

I have a 05 xB that has a very rough idle that rattles my hood originally when idling in drive or reverse, now it will do this on occasion in drive too.
My dealer stated that I need a valve adjustment since the car is at 50,000 miles.

I did the repair at a cost of 300 dollars. It took care of the issue the first day and slowly over the week has gone back to the original issue.

Help!

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adamisbomb

my 05 has about 55k and has been exp a rough idle as well. not enough to rattle the hood, but i can see the rpm gauge changing by about 300rpm up and down. this is only when its really cold outside, and the times i notice it has been in the middle of a 500 mile plus trip......sorry im not more help

Bossman

mine only gets rough right at the time for regular service on the car....once the oil is changed, my rough idles seem to go away.

adamisbomb

oil was just changed on mine. im not sure what it could be, awhile back i bought some of the fuel system cleaner and it ran alot better after i put that in.

stew32

Mine has also done this too a few times. RPMs will bounce up and down by a few hundred at idle.
The times it's happened, it's been cold and I'd been messing the the ventilation controls immediately before stopping- changing between dash vents, floor or defog.

I assume the vent setting was triggering the A/C compressor and the computer wasn't able to compensate correctly for some reason.

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sprslug_182

The xB, just like other economy cars, have a slight roughness to the idle due to such a drain on the motor from accessories and such. Though, I did end up rerouting my crankcase gases from my intake to a small filter that vents into the engine compartment. I wouldn't recommend doing it where you have inspections unless you can change it out fairly easily. I noticed my rough idle go away almost immediately after doing so. This is because the emissions controls that run the crankcase fumes into the intake actually drop your octane rating a lil, which could and will cause a change in idle.

Hope this helps.

Jan06xB

Any chance you have not checked your spark plugs in a lot while? Check the vacuum hoses leading to the intake manifold for air leaks since that will cause lean mixtures and idle problems. While idling grab and move hoses around to see if any movement will change the idle making it worse or smoother. Cleaning the PCV valve is also a good idea.

OttoMoto

I noticed a rough idle also and i got my battery checked and it was shot so i think the rough idle might be due to the strain on the alternator from charging the battery and running the electronics on the car

Jan06xB

Test that by turning on the headlights and the heater fan on high and see what happens.

CBSIMONSEZ

Clean your MAF sensor.

Jan06xB

Usually a rough idle is caused by irregular air flow or fuel flow and not a MAF sensor which would affect all cylinder A/F mixtures not just a couple to make it idle rough unless it is so far off that it doesn't run well.
My xB idles so smooth that there is no vibration at all in fact I drove up a steep driveway in 1st gear at about 500rpm without it even bucking.

CBSIMONSEZ

Well ill be ... then me cleaning both mine and the GFs must be a figment of my imagination then. Both idled like crap ... bath automatics .. .both RS1s .. .both cleaned with MAF cleaner .... both idle much much better now.

Jan06xB

Did you find the intake connections to the MAF loose causing an air leak? Could be you fixed an air leak when you cleaned the MAF or the MAF was really dirty affecting the ability to measure small variations in air flow. You would think if the MAF getting dirty was going to happen so often they would have a cleaning hole to spray some cleaner on the sensor without opening it up.

vintage42

And mine idled for a 1/2 mile in a traffic tie up, doing about 10 mph at 700 rpm in 2nd gear with foot off the gas.

Jan06xB

It will do about 2-3 mph in 1st!

Ya gotta love the VVTi to keep the engine turning over at such a low speed so smoothly.

adamisbomb

mines still idling rough....its better in N but in D it is still rough. ill try to clean the MAF

Jan06xB

Listen to the exhaust in Drive - is it steady or has a regular skip or random skip.

bbszero

iTrader: (6)

Same on mine, it idles perfect in N, but in D, it's getting even rougher. i've cleaned the MAF, checked everything like hoses and nothing. I'm gonna try some new plugs.

B2FiNiTY

I believe there was a how to on cleaning the sensor. Does anybody have a link? Thanks.

adamisbomb

yeah a link would help on how to clean the MAF.