Car has been doing this since I bought it a year ago, and I Can't seem to find the issue.

Issue:

Driving down the road with a warm engine it feels like the transmission goes from lockup to slip. Between 40-70kmph the rpm "surge" up and down about 200-300rpm. If I move the shifter into manual mode then the surging goes away

Parts replaced:

Transmission Fluid
MAF
Coil packs
spark plugs
engine oil
injectors
fuel filter

no check engine light
no specialty volvo codes
fuel milage is around 10-11 L/100km which is pretty decent for AWD automatic.

any ideas on where I should go next?

-Garrett

 

Called a couple more volvo shops and got some different responses. some say, "replace the valve body", others have said, "replace the transmission", ipd has a good thought, "maybe its the engine not the transmission."

Guess I never thought of that, I'll go unhook some engine stuff to see if that changes anything. Just weird that it goes away when I pull it into manual shift mode.

-Garrett

 

surging while holding the accelerator steady is normally due to bad O2 sensors, typically the "up stream" sensor

get them both check and or replaced and it should be good. in my gads car it got so bad that he would floor the pedal and nothing would happen then suddenly the car would take off like a rocket, all the while the rpm's would surge just like that.

 

I was thinking of replacing it but that is a $200 hunch... thing that gets me is that it completely stops when I pull the shifter over into manual.

 

well before you said this i was pretty confident that it was the issue

have you disconnected you battery recently? if so there is a slight chance that your ECU may have lost a bit of its programming. (this time its really just a hunch) but perhaps you car car your car reprogrammed and updated.

 

I haven't disconnected the battery in probably 5 months. I brought it to volvo and they updated the software and did some stuff, but nothing fixed the issue.

Just was on a highway trip from calgary to chilliwack and did 505miles on 60 liters of fuel, 7.4 L/100 or 33.5 mpg, that o2 sensor should be decent... lol

-garrett

 

Call the dealer and ask if your car is covered for the ETM issues. Saw over at MVS forum about problems on 01-02 trans. and ETMs.

 

called about 6 months ago for that, it was only available for 10 years from manufacture date, and my car wasn't the affected model.

I also called Xemodex and they confirmed my car isn't affected by that TSB.

Something so simple, yet has me baffled... And what a PITA to drive.

-Garrett

 

AW 55-50SN / AF 23-33 Diagnosis and Valve Body Information - PDF

page 13,14,15, I did a SLU solenoid adjustment. Not supposed to drill the hole on the car... so I used a air hammer and made a pin hole while getting no debris inside. Used a 3.0-3.5mm allen key and perfect. Firmed up the 1-2 upshift, and completely fixed the 30-40mph surging. Completely new car and it was free.... just months of looking while mostly drunk.

Car does have a small clunk shifting 3-2, but the bottom transmission mount is torn, so I'm thinking that might be the issue there.

-Garrett