I have a 2008 Uplander/ 3.9 v6. Automatic. 160k miles

Sometimes when I go to stop I can feel a small vibration - like rotors with hard spots. It does seem to get worse as I drive and the vehicle warms up.

Then at seemingly random times, when I start to accelerate after a complete stop I'm getting a vibration and 'pop' sort of like the brakes are holding on then letting go. It briefly activates the traction control system (I the note flash on the status readout flash). This anomaly is not consistent, sometimes it's much worse than others, sometimes it will occur when coming to a stop.

I thought that the Automatic Traction control might be unhappy with the anti-lock system.

The car runs fine otherwise (well the cruise control isn't working but I suspect that's another issue)

Thanks for any pointers!

Jamie

 

Hey there,

I can comment on the problem you have when accelerating from a stop.
I had the same issue with my 06 montana sv6 at around 165 000 km. it would hesitate/vibrate and then "bang" into gear and take off. I had it scanned and it was a bad shift solenoid in the transmission. Note that the code was there although i had no lights present on the dash. I suggest you change all the solenoids (about 3 or 4) in there if you plan on repairing the van since getting to them is tough and they are relatively inexpensive on websites like rock auto.

Hope this helps

 

It does help in that it tells me I need to find a better DBD2 scanner. I'm using Torque Pro and a Bluetooth connection, not just looking for a dash indicator. Not wanting to assume, but replacing the solenoids did the trick for you? How many miles ago and what was the repair cost?

I could possibly do it myself, I replaced the auto transmission in my 2001 Beetle, solo. But I might be willing to spring for having another mechanic do it if I can justify the cost.

Thanks!

Jamie

 

Correct, replacing the solenoids fixed my issue. Repair was done just over a year ago at 165 000 km . The van now has 190 000 km on it. Cost was around $700. Took most of the day since the sub frame had to be lowered to gain access to the side of the transmission. (I believe drivers side)
As for the scanner, I use a device called Bluedriver with the bluetooth connectivity.

 

Cool! Was it just a local shop? Or did you take it to the Chevy dealer?

 

So I did find the scan code for the transmission (p0773) and am now trying to decide if I'll do the work or hire a local shop. It doesn't look too challenging but maybe it still would be worth having someone else do it. So you replaced which solenoids? Do you have a parts list? Very much appreciated!

 

Alternate quick fix might be to try some TRANS TUNE which is a SEA FOAM product. It is specifically designed to dissolve varnish buildup in the transmission. Varnish is what gums up the solenoids. There may be other transmission oil additives that target the varnish to help, but I do not know what they are. I had to hunt for this one. Also don't overlook your TCM as the possible culprit. If you unplug it and your SHIFT control magically returns to your gears it hopefully is not the solenoids which is a job for experienced mechanics. Its too big a job for the average person. Regardless the Trans Tune can most certainly help as a preventative.

In addition to the Trans Tune I mentioned above there is no way you can go wrong adding a dose of the LUCAS STOP SLIP.

Just keep in mind you do not want to overfill your transmission fluid, so it would be best to do a transmission fluid change when adding the additives. Although it could not hurt to add in the Trans Tune beforehand and drive it for at least 30 miles if you still can drive it. In fact leave it in for a week if you can. Then do the transmission fluid change and add in a new bottle of Tran Tune and the Lucas Stop Slip when you refill the transmission during the change. That way you can control the level and not overfill.

Mind you I said transmission fluid change; NOT A FLUSH which could do more harm than good. I drive a 2008 Uplander LS 3.9, so what I have mentioned here comes with some experience. I am by no means a pro mechanic. What I have mentioned I wish someone had advised me sooner about. I had to dig and dredge up the ideas here on my own and it took awahile. Especially the part about the TCM. I'm still in the process of getting that taken care of. I came to this forum looking for some information, or ideas, but found nothing of much value to my situation. I left the information I have obtained so far merely as a courtesy to any chance would be visitor needing some help.