Engine Rev on start up

[digitalputty]

Hiddy Ho Folks! :P

Zoomer, a 2003.5 1.8T Manual tranny, acted up today. Once I started him up (foot on brake other foot on clutch in nuetral) his engine revved to 2,000 RPM and dropped down to normal after 2 seconds. It sounded like I had hit the gas! 0_o ...

I have noticed that his tachometer (the RPM guage) has been crazy lately. Bouncing between 750 RPM and 900ish RPM while at rest. Cold and warmed up.

No lights. I did have the O2 sensor replaced about a month ago. But, the tachometer was bouncy before that.

What could be up? I did a search on here since I remember someone with the same/similar problem before but, I couldnt find the thread.

Thanks in advance!

Larissa

[mezonesxbox]

There's been some talk about the throttle body.

[Smileybug]

My car had the exact same issue. At first I thought maybe I was hitting the gas by accident but I would make sure my foot was far from the gas when I started the car and it would still do it. It wasn't all the time but it did it enough that I thought something was up. It got to about 2000 rpms and then dropped, just as yours is doing.

What fixed mine: replacing the coolant temperature sensor. I threw a code on that and my bf did some reading up on it. Apparently because it deals with the temp of your coolant, it will rev the engine if it thinks its too cold. I put a new sensor in it, no problems since.

[digitalputty]

I didn't mean to say O2 sensor in my initial post. I actually did mean the coolant temp sensor - and I just realized it after reading your post. Sorry for my lameness ... heh. Guess I cannot think straight.

My fiance said that maybe it is a vacuum hose leak? I am having a loss of power at times around 3,000 RPM in second gear ... which is sad since that is my favorite gear. It kinda bogs down like I let off the gas and then hit it again. I had my boost read and they said it was normal.

[SilverSportNOLA]

Third gear is my new favorite .... 2nd was before chip.

No sounds of boost loss? Check that the temp sensor is plugged in all the way, heck check that all of them are plugged in all the way, plugs and MAF also. Also check your Diverter Valve, probably about time for the OEM one to give out. The springs get weaker and let boost bypass them.

I have not experienced what you are, but I have been having a VAC leak for 2 weeks now, 12in instead of 22in, and yesterday was the first time I really had a chance to get on it, still feels the same, but couldn't get more than 10PSI on the Gauge, usually spiked at 21-22PSI. On the plus side, I seem to be getting a little better MPG.

[digitalputty]

I would imaging a vacuum leak isn't fun. Bleh.

I believe my Diverter Valve was replaced by the dealer about 2 years ago ... for weird fluttering. That and the BOV.

Zoomer didn't do this today. But ... I will let ya know when it does it again.

BTW - something Ive been meaning to ask but didn't want to start a new thread for something so ... silly. If the car isn't showing a CEL (or any other light) ... does it still carry codes? If I were to vag-com the car even though there arent any CEL's ... would it have codes if there were any?

See ... silly isn't it?

[Smileybug]

Even though a CEL may not be on, codes may still be thrown. So scanning the car might be a good way to go on this one.

[digitalputty]

That is probably what I will do. It will have to wait until next week around Tuesday though. No money and no time. ARGH!

Thanks for the help