[Bigringking]

Hello. My wife drives our 1999 S70 AWD with (I think) the 2.5l turbo five. For a while (but not always) the engine idle will vary from 500 to 8-900 about every other second. Any ideas what to check out on this before I take it to a shop? I am kindof handy with vehicles but am not sure what to check and what parameters should be. I do know that the hunting idle usually occurs when the car is warm (ie not first thing in the morning). Oh, and we garage the car all the time.

Thanks,

Ed

 

[Tech]

Check the throttle body and clean it.A dirty throttle body will cause an uneven idle.

 

[Bigringking]

QUOTE(Tech @ Feb 27 2005, 07:57 PM)Check the throttle body and clean it.A dirty throttle body will cause an uneven idle.

[snapback]4135[/snapback]​

Does that need any special cleaner? My old Expedition and the gas F250 required a special cleaner to get the varnish-type crud out of the TB. Actually I just used WD-40. I will have a look. Thanks for the tip.

Ed

 

[Bigringking]

Forgive me but where is the Throttle Body? I have the 2.4l Turbo.

Is it under the manifold? It must be. Is there a way to get to it without taking off the intake manifold? Looks like you have to either take off the manifold or take off the front of the car.

Thanks

 

[Tech]

You take off the big black induction hose from the intercooler to the throttle body under the intake.Then there will be 4 10mm head screws you need to remove to get the throttle body loose.If you want to remove it all the way you will also have to remove the back starter bracket.The throttle body wires run behind the starter then into the front of it.

 

[BarmyArmy]

I had an old fiat which had a piece of grit which had got past the air filter, when the grit part blocked the air intake it caused improper combustion and the engine management then tried varying the fuel air mix to compensate causing an uneven idle.

Check the air filters and intake ( internal into the engine ), not the external "air scoop"

Hopefully the first last and only comparison I ever make between a volvo and a fiat.

Barmy