I've noticed that sometimes when I'm in traffic on the freeway, and I'm trying to let the car just ride along at idle (I have an automagic) the car will sometimes start reving up on it's own. It doesn't always do it, but I've seen it pick up to around 1500 rpms by itself. It doesn't surge, it will pick up and keep going until I slow it down with the breaks. It will even do it going uphill, (uphill in Miami means going uphill on the overpasses) it's not like it's picking up speed going downhill. Or sometimes if I'm cruising at a low speed, lightly on the gas, when I take my foot off the gas, it will just stay at around 1500 rpms.


Why doesn't my car like to idle at peace???????

 

Could be a number of reasons. How many miles are on the car? What kind of gas do you use? Have you used any engine cleaning agents such as seafoam? Any electrical issues that you have noticed? Dimming headlights, interior lights etc? Could be a grounding issue. Ever changed the fuel filter? I would start with the easy stuff and get your engine cleaned out. Use seafoam or some fuel system treatment. See if that helps. Then look at the electrical stuff.

 

167K miles
I think I use 89 octane, It's the middle one on the pumps.
No electrical problems
dimming headlights, only from the bass hitting on my system (getting a capacitor soon)
fuel filter was changed around summer of last year.

What else?

 

Oh, and yeah, I'd done the seafoam treatment already

 

Have you taken a good look at your throttle body? The throttle cable may need adjusting or replaceing. You could also try cleaning the outside of the throttle body. Mabye there is some grease and or dirt that is making things a little sticky.

 

I've cleaned out my entire engine bay, cleaned out the butterfly in the TB really good, done the seafoam treatment. So I don't think it would be anything sticking for that reason.The throttle cable seems to be fine. The car idles normal every other time, responce is alright on the throttle. I really have no idea what it could be.

 

THe same thing happened on my car and it was 2 things vaccum leak and a dirty TB sticking a little.

Hope that helps

Brian

 

How can I look for vacuum leaks?

 

you can use a propane torch (don't light it ) just move it around the suspected area,if the idle changes you know where the leak is.

 

ummm... no. There has to be a "nicer" way to find them.