: Holding RPMs, any ideas?



Kadonny
08-30-06, 09:39 AM
So I took my 06 into the shop yesterday to look at 2 problems.

First was my holding rpms. I know the throttle response on the stock cars is not the best, so when you let off the accel and engage the clutch, it takes awhile for the rpms to get back down to idle. I have more of a problem than that. If I clutch at 3k or higher to slow down or even downshift sometimes, the rpms drop to 2k, then sit there for (I counted even) 2 seconds, then drop down to the regular idle level. This of course happens only periodically and it could not be duplicated in service. No codes throw etc.

What could be causing this? Sounds like a computer problem IMO. Anyone else see this ever?

I would love to tune it and see if it goes away, but 06 tunes are still hard to come by.


Second issue was of course the dripping rear diff. Service says overfill problem. How the hell can Getrag be overfilling these things so badly?


Other than that, the car has been running great.

keeksv
08-30-06, 04:53 PM
My idle wanders around a bit occasionally, but my car/tune is far from stock. IIRC it did it occasionally when it was stock, too--especially if I was slowing at relatively high RPM (i.e., after downshift) then depressed the clutch just as I was about to stop.

Make sure your air intake clamps are tight. Not sure I would worry too much, but hey, the car is under warranty, so if it does bug you, take it in.

I'll be watching this thread.

BBV
08-30-06, 11:27 PM
Interesting,
My ’06 just started doing the same thing at about 2600 miles.
Exactly as you described with the exception that I can reproduce it 100%.
Hangs at around 2200-2100 rpm for a couple of seconds before dropping to normal idle speed.
It has always, as my ’05 did, hang at about 1200 rpm for a second or two on it’s way down to 900.

Please post back here when you find the problem. I’ll bet if I take mine in they’ll say the headers and Corsa have affected the PCM program even though it started 2000 miles post header install.
For now I’m going to live with it in hope that StealthV’s LS2 will be available soon.

Edit: I checked the intake side and everything is tight.

04CTSVFLA
08-31-06, 09:10 AM
happens to me too, if Im going down a hill, traveling 40 I can take my foot off the gas, and the rpms hold at 2k forever.

50 4Ever
08-31-06, 02:04 PM
Mine hangs for a few seconds also, but I have never made a mental note or the RPM's. The guy that did the tune on mine is a GM Rep that has had two V's and said he thought this was a "feature" added by Cadillac for smoothness when shifting. When shifting up the RPM difference for the same speed is about 500 RPM. So if you shift up at 2500 RPM within the 2 second window the RPM's drop to 2000 and when you let the clutch you should feel little or nothing since the computer matched the engine speed and the wheel speed. Also when shifting down, if you don't blip the throttle and the RPM's hang at 2000 you won't feel as much of a jolt as if the engine returned to idle when you shift.

Just a thought.

:thumbsup:

Kadonny
08-31-06, 02:42 PM
Good thought 50 4Ever, but it does not happen to me anyway on a consistant basis therefore I would think it is something that is not meant to happen.

It does not affect the driving all that much and is more of a nuicance that anything else. I would love to see if a tune takes it out.

BBV, I would love to get the LS2 tuned. Its been a year now since the cars are out, I hope they get the software done soon.

keeksv
08-31-06, 02:48 PM
Tune didn't take it out of mine...

BBV
08-31-06, 06:33 PM
Just a guess but is the dual mass flywheel the cause?

I think your right 50 4Ever, it may be a design feature whether by hardware or software however it seems more pronounced lately with my car.

Whatever the cause I dislike it. That’s why I like manual transmissions, so I control the car rather than the other way around.

keeksv
08-31-06, 07:10 PM
Exedy clutch and flywheel here, still does it....

50 4Ever
08-31-06, 09:47 PM
Just a guess but is the dual mass flywheel the cause?

I think your right 50 4Ever, it may be a design feature whether by hardware or software however it seems more pronounced lately with my car.

Whatever the cause I dislike it. That’s why I like manual transmissions, so I control the car rather than the other way around.

This is a nuisance to me also, I always control the car with the transmission and gas. When I blip and downshift, the hanging of the RPM's are a bother, especially on the road course.

I have a tune and it could not be tuned out.

:confused:

thefly
09-01-06, 08:58 AM
could clutch slave master cylinder (may not be saying the part right). pre 02 ZO6 had a similar issue also. i think what is happening is when you disengage the clutch it (the pressure plate) moves too far over and kind of sticks there for a second. my 01 vette did the exact same thing sometimes, though i have noticed it happening more in the caddy...

Kadonny
09-01-06, 09:09 AM
Wow, so sounds like it is something that a lot of us are experiencing. Is it something that does not bother most people? Funny I just never saw it brought up before, at least not that I remember.

SBONES
09-01-06, 09:37 AM
mine does it too...and is tunned....so i assume they all do it, it doesnt bother me at all.

StealthV
09-01-06, 10:17 AM
Tuning won't fix it if the tuner doesn't touch it. Most don't because dyno tuning is typically focused on WOT performance and not much else.

What many are describing is completely adjustable. Last week I went back to the 100% factory settings and it sucks.

atdeneve
09-01-06, 10:24 AM
Okay StealthV, I'm going ... but ... um ... can you just tell me ... uh ... where do I go?

BBV
09-01-06, 11:42 AM
Tuning won't fix it if the tuner doesn't touch it. Most don't because dyno tuning is typically focused on WOT performance and not much else.

What many are describing is completely adjustable. Last week I went back to the 100% factory settings and it sucks.

I thought I remembered seeing that option on your worksheet.

I’ll have the option to remove that “feature” checked when you are ready to do my tune! :thumbsup:

Kadonny
09-01-06, 02:02 PM
Whoa! Rick/BBV are you tuning the LS2 yet?

Please tell my you are, please!!!!!!

BBV
09-02-06, 10:13 AM
Whoa! Rick/BBV are you tuning the LS2 yet?

Please tell my you are, please!!!!!!

Mine is not done yet. Soon come.

Dennisscars
09-02-06, 11:20 AM
This is an emission control strategy. Hard decel's makes birds fall from the sky.

paulsV06
09-02-06, 11:30 AM
Have an 06. No mods. Does the same thing occasionally..