Idle surges during warm up, dealer wants $600?
 

Hi all, I've been having some trouble with my 2004 6-speed. A few months ago it started doing a strange idle surge when cold. It fires right up and does the normal fast idle for a few seconds, then when it switches to the medium idle it will surge between around 1500 RPM and 2500 RPM back and forth for 10 or so seconds. Then it goes down to normal idle and all is well. Only happens when starting and when cold. Aside from that it seems to run perfectly fine.

I took it to the dealer a few weeks ago and they said I had carbon build up on the rotors and the seals. They recommended a cleaning and new plugs, which I let them do. Cost me $600. That didn't fix the problem. I took it back and now they say they found the throttle body is bad and needs to be replaced. They said there's a sensor in it that's failing but the whole throttle body needs to be replaced. This is going to be another $600.

So, I want to ask if this sounds like BS or what? If it's legit and will fix the problem I have no problem ponying up but if I am being jerked around I'd like to know.

Thanks!

Jason

Update: Here's a video of what it's doing. This is right after start up on a 40ish degree day after sitting all night in the garage.
http://www.youtube.com/watch?v=dQl37zvVg7s

bs get your 600 back

Which part is BS? All of it? Any idea what the problem is?

if you push the clutch in, does it stop doing that?

neutral switch on the tranny is my suggestion... if that's the case you're getting super ripped off

Spray a cleaner in the TB, also put a cleaner in your gas.

That is such a minor issue....... I wouldn't pay 600 bucks

Thanks for the suggestion! I will go out and try that in a bit and report back.

Jason

1 - tune up ????
2- maf sensor clean up ???

yeah. pretty sure our throttle body has a redundant [sensor] setup, so unless they both failed in a very specific way I would think you'd get a code for that. So I'm skeptical about that too...

think there is any chance of getting your first 600 back for the 'cleaning'?

I doubt I can get it back. One of the things they did was install new plugs too.

Okay, looking at the paperwork here is what all I got done. I guess it wasn't as bad as I said really.

Oil change: 34.95
Diagnose idle problem: 49.50
Combination intake cleaning and fuel injector service
Installed F-I/FLUSH
Installed TBB FUEL KIT
Completed F I service, de-carboned complete system
All above was 219.95
Installed n3y3-18-s30a-9u spark plug set 222.70

Grand total was 583.92

I don't really care too much about that $600. I feel like I got work that needed to be done. It's the next $600 I don't wanna pay unless it's going to fix the idle problem.

On the paperwork for the idle problem they said:
Caused by: DUPLICATED IDLE FLUCTUATION, FOUND ERRANT SIGNAL FROM THROTTLE BODY, NEED TO REPLACE THROTTLE ASSEMBLY

Yep, that did the trick. Pushing in the clutch stopped it instantly. I tried it three times and it clearly worked.

So, that's the neutral position switch? Can you give me a real quick explanation of what exactly is happening?

I looked at my service manual and it looks like this is a pretty easy DIY fix, assuming I can get to it.