engine/throttle surge
 

Hello folks, I am new to the forum and wanted to get some feedback on a problem with my 2006 HHR LT 2.2. Automatic 96,000 miles.

When I am driving in overdrive my engine will surge and the RPM gauge will move up and down. It is very annoying. I can't tell if the "drive by wire" throttle is going bad or maybe a coil pack or wire going bad. If anyone has experienced this problem please respond, Thanks. :clueless:

Welcome to the site :smile:

There are a lot of things that can cause your symptom. You may be able to rule out a trans problem by driving it in different gear range.
Also when it is acting up lightly press down on you brake pedal just enuf to get the brake lamps to come on. ( don't do this test for long because you can overheat the brakes)

This will defeat the lock up convertor. If you problem disappears with ether of these then we can assume that your surge is from the trans changing gears.

Also stop by your local part store and get the codes read. Even if the check engine light is not on there maybe a pending code in there that can lead you in the right direction.

:welcome8: to the forum!

The first step would be to head to your local auto parts store or technician to have them "pull the codes".

Even if your Check Engine light has never illuminated, the vehicle may have stored trouble codes. If any codes are found, post them up here.

Is the rpm fluctuation occuring between 42-45mph under light throttle on level ground? I'm asking this because there are certain combinations of road speeds and throttle openings that can cause the torgue converter in the transmission to go from "Locked" to "Unlocked". When this happens the tach will bounce up and down a few hundred rpm.

If it's going from fourth gear to third and back, that's another kettle of fish altogether.

The most important thing is getting the codes pulled, without them, we're flying blind.

In the past, members have found this sort of thing to be a TCM problem. There may even be a TSB.

Mine does this between40 to 45 MPH.

Donbrew maybe correct. Explore this thread, there is even a youtube video of the surge condition. https://www.chevyhhr.net/forums/show...ighlight=Surge

I dug that one up for you

Hi no1uno,

Have you brought this to the attention of your local Chevrolet Dealership? I'm not sure if you were going to attempt to tackle this one on your own first, or if the dealer route is for you, but if you decide to work with your dealership let me know! I can be reached via PM, please include your full name and contact information, VIN, current mileage, and preferred dealership.

Sincerely,

Jonathan A.
Chevrolet Customer Care

Change the transmission fluid. At 117k miles on mine it has been doing the same for the last say 15 thousand, now it drives smooth in lockup and goes into overdrive @ 60 fast too.

I have the same issue. No codes. I cleaned the MAF and TCM. So far so good.

2006 hhr 2.4 lt 197k miles