Rough idle and poor acceleration when hot

Spags · Post by **Spags** » 06 Jun 2010, 03:07

Hi,
I have a 2001 S60 2.0t. When the engine is cold it idles perfect and has full power on acceleration. However, after it gets up to full temperature it begins to idle rough(tach needle seems ok) and has a loss of power and a slightly different exhaust note. If you have the window down you can here a nocking sound coming from the engine. I plan on changing the plugs today if it stops raining. I bought the car with 83,000 mi and I'm not sure when they were done. Does anyone have any other ideas or thoughts here?

Post by **matthew1** » 06 Jun 2010, 08:44

New plugs will rule out plugs, so yes do them.

These temperature-related performance cases are a bit tough because they bring in the possibility of electrical issues. Because metal expands as it gets hot, electrical connections that are ok cold can become intermittent hot, or vice-versa.

The way you want to work this is from simple/cheap to complex/expensive, both mechanical and electric.

_ Look at your battery - does it have a date? Is it old?
_ Battery cables - corroded? Loose? Broken? Crimped?
_ Fuel line looks ok?
_ Engine bay looks ok? Things going somewhere get there?

Those are Simple. There are probably more I'm not thinking of. Get back to us after checking that stuff.

Spags · Post by **Spags** » 06 Jun 2010, 14:37

Did plugs today, idle seems better, acceleration is still becoming sluggish when car is running hot. I'll work on other suggestions. Thanks