car revs while in park and at idle

[pwnzer]

When I turn my car on in the morning to defrost it before school it revs on its own for a while. It will be at idle and rev up to about 2000 or so every 15 seconds or so. Is this normal? I havent noticed it before.

 

[crusher966]

I had this happen to me before. Check your pcv valve thats what it was for me.

 

[pwnzer]

Dumb question, but how would I go about doing that.

 

[BigSorn]

its the little valve thingy on the back on the valve cover. just go buy a new one from a dealer, not a parts house(they leak right out of the box)

 

[pwnzer]

Thank you. And as far as replacing it? How much time do I need, and how difficult is it, and what must I do?

So my pcv valve is good, I didn't check for vacuum though. I don't think any hoses could be clogged cause I don't have any other problems. Any ideas?

 

[crusher966]

The PCV should only take at most 5 minutes. You can easily check it by removing it and shacking it. If you hear a ping type nois its good if you dont its bad. Well vaccum lines dont usally get clogged usally they have small holes that release the pressure vital for your PCM or ECU to know. If your PCV is good then you will need to check the vacuum hoses. The easiet way is to start the engine put your head in the engine bay and listen for a pshh type of sound if you cant find where its leaking then you have to do it the hard way which is taking a pressure gauge hooking it up to each vaccum line and look for a pressure drop. You can find these at almost any store like walmart, kmart, pepboys etc. Try doing these checks before you buy anything. Always test the part in question before buying it. Theres no reason to replace a good part. =)

 

[LiquidX]

Let me ask you this, is your car manual or auto? Manual could be the TPS Adjustment or DmTaLoN's Idle Speed Control Test/Fix Page! and the auto could be the auto tranny brain.

 

[pwnzer]

Its an automatic, and thank you I will check the hoses.

 

[GSXSixteenG]

Does it still do it once your car warms up? I'm thinking along the line of a vacuum leak..

 

[pwnzer]

Once it warms up no. and I actually think I noticed an odd hissing noise while working on my car in the shop the other day, I thought it was just the compresser next to me. So I take it I should start checking all my hoses?

 

[95gst16g]

Once it warms up no. and I actually think I noticed an odd hissing noise while working on my car in the shop the other day, I thought it was just the compresser next to me. So I take it I should start checking all my hoses?

My car just started doing the excact same thing it is annoying.If I find anything out I will let you know.

 

[pwnzer]

It is and its only when I first start it up. Once I get going everything seems fine. I have to check it out on thursday. Ill be sure to post up my findings too.

 

[doubleclutch99]

The fast idle air valve can cause the same issue if it is not working correctly.

 

[Here4u2hate]

Your cars computer is made to idle a little higher at start up, made to warm the car up faster... if its surging at idle check your vacuum lines or your bliss screw...

 

[xtr3me]

My car does the pretty much the same thing. It idles at 2000rpm then every 5 or so seconds it drops down to 1400, untill it fully warms up.