surging!? anyone experance this?

[wht95ext]

just bought new 05 ext tb 12 days ago and already back to dealer. for a few things most consered about surging the times it happens most is say you are turning into a parking spot and let off both acell and brake to coast in. about the time you go for the brake to make your stop the thing surges forward !! wtf . ti happen to my wife on test drive but i figured it was her (even though she said it wasn't) but happen to her repeatedly and to me twice( it her vechile primarliy ). also seperate problem backed out of driveway and put in drive, steering was tight for about an 1/8 of a turn( im a auto tech and other techs from cool climates will know what this means) it was similar to the grand ams and other gm fwd cars from late 80's to early 90's with bad racks they would do this while cold mostly but the tb was warm. sorry post is long but just wondering if any gm techs and or owners have experianced same. truck has only 700 mi. on it

[Jozuah]

just bought new 05 ext tb 12 days ago and already back to dealer. for a few things most consered about surging the times it happens most is say you are turning into a parking spot and let off both acell and brake to coast in. about the time you go for the brake to make your stop the thing surges forward !! wtf . ti happen to my wife on test drive but i figured it was her (even though she said it wasn't) but happen to her repeatedly and to me twice( it her vechile primarliy ). also seperate problem backed out of driveway and put in drive, steering was tight for about an 1/8 of a turn( im a auto tech and other techs from cool climates will know what this means) it was similar to the grand ams and other gm fwd cars from late 80's to early 90's with bad racks they would do this while cold mostly but the tb was warm. sorry post is long but just wondering if any gm techs and or owners have experianced same. truck has only 700 mi. on it

im no tech however i have had a surge before. it was due to changing fuels from ethonol to straight gas. it went away after a tank or so. if the thing has 700 miles on it from 05 you would think its been sitting a long time so possibly the battery was dead at the dealer when you bought it and the ECM lost its idle and throttle position, i my self would drive it for 50 miles then see if it still does it. if so then i would certainly request the dealer fix it free of charge (of course)
the rack issue is somthing i have not come across so i cannot comment on that. my 04 LT with 76K+ does this on occasion but not anything ike the grand ams did its lust a bit "thick " till it gets warm, yours was warm so i have not a clue.
more will chime in.
Welcome to trailvoy.
Josh

[rbarrios]

wow- a new 05....
wonder if a simple battery disconnect for 30 min will have it forget the stuff it learns-
same method as many of us do when we clean the throttle body and disconnect battery so that it relearns stuff with a clean throttle body.

Also if its an 05- I wonder how long it had gas sitting in it while it was waiting to be sold? Gas could have gone bad?

[wht95ext]

thanks josh, beleve it or not this only had 68 mi. when i bought it so the fuel should be ok have been running top teir 87. it sat at the stealer for a while though but maybe relearn isn't complete.

[wht95ext]

info i forgot 4.2l ls

[torker]

Make sure the dealer did all the computer flash upgrades maybe.

[Bad1]

I work in parts at a dealer, and had mind in several times for this problem. I know exactly what you are talking about and after all the suggestions with gas & updating the PCM. It was determined to be a NORMAL. There even was a bulletin stating that this is a normal condtion for the trailblazer. I have an 04 with the I6 and it does it almost every time backing into the garage while coasting in the stall.

[MTPockets]

On a cold start, the idle speed on my 2005 4.2L will ocsillate up/down slightly when coasting in gear. On mine it goes away after it starts to warm. Throttle by wire (no idle air control system) are strange beasts.

Joel

[torker]

I'm still running the Lucas and Cenex 87 . Only driveability issue is the hot soak. It is less and goes away quicker than when it was warm out but it is still and issue after being in a store for 20 -30 min. it bogs. Not sure about a surge. Maybe vacuum leak? I've also steered away from the ethenol .

[wht95ext]

thanks everyone dealer says nothing is wrong with anything?? guess they think its all normal too. i did have them flash with latested updates but still surging.

[Jozuah]

thanks everyone dealer says nothing is wrong with anything?? guess they think its all normal too. i did have them flash with latested updates but still surging.

how many RPM does it surge? another thing i was wondering is it a 4X4? now this i am going out on a limb totaly, but is the rear end a full locker ?
did the time it spent at the dealer sitting cause the rear end to get "sticky" and now the rear end isint ratio'ing down for turns? do you experiance bunny hopping ?
IF the rear end is stiff then that would explain the surging as the motor loads up due to the solid'ish rear diff.then the PCM would try and compensate for the stiffy and idle up and around we go.

listen this is JUST a thought that hit me yesterday as i was pulling in to my parking spot and i had it in 4L (testing for the trip to utah) and it surged like a leaking intake manifold.
loaped even.

[DeeCee]

I've got the same problem on my wifes '02 SLE. Have had it for close to 10 mths now, and all of the sudden surging!!! Fun stuff almost rearending people at stoplights, fun stuff.

Have a CEL now too, cam position and rich condition - right bank. Battery reset helps for a few miles.

I"m going to try cleaning TB, do trailvoy's have IAC's? I've seen this issue on DSMs I used to own having idle surge.

[Neil Patel]

I have 80K and have had this problem since brand new. Was told it was normal twice by the dealer and have heard others asking about it on here too. A tune may help, because the drive by wire and computer seem to be the culprit. Mine seems to do it when the wheel is turned, leading me to believe the engine is over adjusting to needing some extra power for the steering pump. Either it has gotten better, or I have just gotten used to it, because I can't recall seeing it for the last few months after I got a tune.

[wht95ext]

thanks for all the replies truck still doing the samething but is manageable.:( but i was thinking of a tune anyway so maybe thats the next step. gm tried all there avalible fixes i was told.

[jrpjr61]

I got an 05 and it occasionally surges under the same conditions you noted. If you guys brought it into the dealer asnd they said it s normal I am not going to mess with it but if someone comes out with a TSB or other info I would appreciate it

[brettster98]

try running some sea-foam from(auto-zone) in the tank that stuff is amazing.. i've put that stuff in my boat,truck,car the only thing i do is i'll run the tank half way down and dump the can in trying to double the mix from what it says on the can..

[PROSPHOTO]

If you have a new TB (under 12K) I would NOT add anything into the fuel :nono: ...GM has specific cleaners, you don't want the dealer to accuse you of anything :mad:

Speak with the service manager about having the condition re-diagnosed by a different Tech. If you have another Chevy dealer around, try them :rolleyes:

I don't think this condition is normal, and the dealer may not be duplicating the condition leading them to believe that the TB is operating normal :crazy:
It's under warranty, let the dealer do all of the work relating to any driveability concerns...you should not be paying for anything out of pocket.

[Super 88]

try running some sea-foam from(auto-zone) in the tank that stuff is amazing.. i've put that stuff in my boat,truck,car the only thing i do is i'll run the tank half way down and dump the can in trying to double the mix from what it says on the can..

just bought new 05 ext tb 12 days ago and already back to dealer. . . truck has only 700 mi. on it


Any new vehicle with 700 miles on it, should NOT need anything in the tank. FWIW my 05 EXT does pretty much the same thing. I look at it as normal in that the RPM seems to drop below a certain limit and the computer speeds it back up to around 900-1000 RPM temporarily.

[topprolmc]

Any new vehicle with 700 miles on it, should NOT need anything in the tank. FWIW my 05 EXT does pretty much the same thing. I look at it as normal in that the RPM seems to drop below a certain limit and the computer speeds it back up to around 900-1000 RPM temporarily.


Unless it is a leftover from '05 (yes, local dealer has a few)....gas sitting in the tank and lines for 2 years tends to gunk up...

[Super 88]

Unless it is a leftover from '05 (yes, local dealer has a few)....gas sitting in the tank and lines for 2 years tends to gunk up...

True about gas "gunking" up (very technical term? :)) but the point is GM and/or dealership should fix it, or at least given a chance to fix it before using any "home" remedies. Read the owners manual, GM states: "In most cases, you should not have to add anything to your fuel. . . . your GM dealer has additives that will help correct and prevent most deposit-related problems."

I still say there isn't a problem - just the nature of the beast so to speak. As Joel said these vehicles do NOT have an idle air control system. If the fuel system was "gummed" up, there would most likely be other performance problems - hesitation, loss of power, etc.

[brettster98]

if you guys have one that is surging i cant see how this should be acceptable that sounds like it would drive you crazy. espesially if your backing up a trailer and it surging. if that was me i would be blowing smoke up the dealers crack until its fix. maybe enough complain there will eventually be a recall..sounds like gm screwed something up and they are dealing with a handful of this problem if gm does not fix the problem than all i was saying is that the sea- foam was a good product that has worked very well for people that have in the past used. i'm sorry if this pisses someone off but the fact is your driving a 30000.00 plus dollar truck and seems to be the one style and make that surges id be mad as hell for that issue

[Super 88]

if you guys have one that is surging i cant see how this should be acceptable that sounds like it would drive you crazy. espesially if your backing up a trailer and it surging. if that was me i would be blowing smoke up the dealers crack until its fix. maybe enough complain there will eventually be a recall..sounds like gm screwed something up and they are dealing with a handful of this problem if gm does not fix the problem than all i was saying is that the sea- foam was a good product that has worked very well for people that have in the past used. i'm sorry if this pisses someone off but the fact is your driving a 30000.00 plus dollar truck and seems to be the one style and make that surges id be mad as hell for that issue

First of all, I don't see it as a problem. Not sure if everyones definition of a surge is the same. As i said b4, on mine if the RPM start to drop too low the PCM increases the engine speed up to around 900 or 1000 RPM temporarily. If that is a "surge" then that's what it is.
If that's all it takes to drive a person "crazy" well ... :D Here's a hint - if the vehicle starts to move faster than I want it to, I apply the brakes. Works every time! :yes: :D :)
The whole point was, (and it's so simple) a vehicle with only 700 miles on it should NOT need anything else to run right, and IF there is a problem it is the dealers/GM responsibility to fix it.
If you or anyone else likes sea-foam and want to use in your vehicle - go for it! It's your money! END OF STORY!
Good luck!