Hi, I am not very active on this forum (I am however on the bimmer forums). Just once in awhile lurker.

This is concerning my wife's car; a 2001 S40. While in Park the car idles with no problem, but while in drive and stopped there is trouble with the idle. Every few seconds it drops only about 100rpm, but you can feel a vibration and it pops back up 100rpm to normal. Sort of a kind of pulsing. When you press the gas is hesitates with the pulse and then goes and drives with no problem. I know there can be numerous problems that cause an irregular idle, but does this situation lead to any thoughts? The car has 85,000 miles on it. Thanks!

 

Any codes stored?
If not try cleaning the idle motor and see if it helps.

 

No codes that I am aware of because I don't have a CEL on. Can you give me more details on the idle motor or where I can get info on it here? I appreciate it. Sorry for being a newbie here.

 

First make sure the Check Engine light works turn the key on and make sure it lights up.

I have to get some pics soon but under the hood on the front of the motor there is an idle motor it is bolted to the front of the intake manifold. It should also have ford written on it. It will either have t-25 screws or 8MM screws holding it on.

 

Thanks for the info. I took it to my local euro mechanic and he stated spark plugs and fuel filter are the culprit. While in there I having him doing timing belt and new water pump given the miles.

 

Keep us posted on how it goes.

 

i havent got time for a full maint..the mechanic told me its gotta be the fuel filter and some fuel inyectors should be cleaned up with some special liquid, he said the sparks were doing fine..air filter is clean, the timing is just a matter of must, running 100,000 is a thing of must, i dont think 85,000 or close but shouldnt be left away...also...the water pump, maybe since its close to the timebelt and its basically the only chance u can get to chance, but the pump is japanese made and very few cases i heard it gets bad on this volvos...now my left light..goes on about 2-3 sec after i turn the switch on, what the hell?