Lumpy idle

[developer215]

Hello again,


Any views on a lumpy idle that you can feel as a vibe thru the seat?
I recently had to replace the DI unit as my engine malfunction light came on and my specialist told me that the idle would get better with a new DI unit but to be honest it's still not very smooth for an expensive sophisticated car.The rev needle is rock solid but the idle feels rough. Other 4 cylinder cars of a lesser pedigree (for example Peugeot 406 and various Rover's) have been better than this.

Any ideas?

John

[Chris 9-5]

You might get a better response to your questions if you posted them in the workshop rather than the performance section.

[Kermit]

John, this vibration problem seems to affect some auto's but not others. We've never got to the bottom of why its like this either. I've noticed mine is worse after an oil change/service but smooths out over the next few months... The next thing on my list to be changed is the torque rod between engine and gearbox, hopefully this might work but i'm not gonna hold my breath.

[developer215]

Thanks guys - reposted. Sorry for the duplicity on the system.

[Chris 9-5]

When I changed the CPS to cure stalling it also smoothed the idle too

[developer215]

What's the CPS?

I also notice that the engine struggles like buggery and produces a knock knock knock when at idle with the steering wheel on full lock - when pulling out for example.

Should have said, it's done 77K

[Chris 9-5]

Crankshaft Position Sensor - try a search


PS...... all these 9-5's struggle at low speed on full lock, infact you should always back off a couple of inches off full lock due to the extreme pressure within the power steering system.