hard acceleration at 40 downshifts, but no upshift until throttle eased off Topic is solved

mp5802 · Post by **mp5802** » 07 Nov 2017, 16:26

My 2001 V70 T5 has been great (after the customary fixes), but in the 3 years I've owned it, it has always had this problem where if you floor it at 40 mph, it stays going 40-50mph and revs at 4000rpm forever until you ease off on the throttle; then it will finally upshift and gain speed. This makes passing anything fairly difficult, especially on a hill.

Otherwise, the car runs and shifts perfectly fine if you don't floor it. It also idles steady and never stalls. Since I drive like an old man (which I am), this seldom bothers me, but I'm told these cars should perform much better (especially the T5 vintage).

When I first got the car in 2014, it had numerous engine codes related to missfires and the ETM. I replaced all the plugs, coils and the ETM, too (rebuilt by XeMODex). Since then I've had absolutely no DTC codes or other performance issues, so there's no hints from the computer. I also had the transmission software updated about a year ago to fix the neutral clunk issue, and had the tranny flushed and filled 2 years ago by a reliable independent Volvo shop. The odometer just rolled over 100K miles.

I can manually shift the car pretty well through all the gears (Geartronic). For example, I can take 3rd gear up to 5500 rpm easily, then shift to 4th. Internet searches on similar "hesitation" problems tend to point possibly at the ETM and/or MAF sensor. Also, I'm seeing threads discussing shift "flares" between 2-3 or 3-4. So, perhaps my car's problem is all in the transmission?

Must remember to repeat this mantra: "I love no car payments, I love no car payments."

Any ideas will be appreciated.

Post by **oragex** » 08 Nov 2017, 06:35

At lower speeds if you floor it in auto mode, does it go to 6000rpm?

Post by **Rattnalle** » 08 Nov 2017, 08:22

Planting the foot on the accelerator of the light pressure turbo will pretty much keep the revs between 3500 and 6000 and the speed increasing at a decent speed up until about a 130 mph when it drops off a bit. I'd assume the T5 is the same but quicker if it works like it should.

It could be that the 4000 rpm limit you're experiencing simply keeps the car from shifting because it isn't time yet. You don't specify if you've had the car hooked up to Vida or not. If not that'd be a good first step.

mp5802 · Post by **mp5802** » 08 Nov 2017, 19:08

oragex wrote: 08 Nov 2017, 06:35 At lower speeds if you floor it in auto mode, does it go to 6000rpm?

I just did another road test, and no, if I floor it in auto mode from say 10 mph, it still holds at 4000-4200, only upshifting after slightly releasing the gas pedal.

mp5802 · Post by **mp5802** » 08 Nov 2017, 19:12

Rattnalle wrote: 08 Nov 2017, 08:22 Planting the foot on the accelerator of the light pressure turbo will pretty much keep the revs between 3500 and 6000 and the speed increasing at a decent speed up until about a 130 mph when it drops off a bit. I'd assume the T5 is the same but quicker if it works like it should.

It could be that the 4000 rpm limit you're experiencing simply keeps the car from shifting because it isn't time yet. You don't specify if you've had the car hooked up to Vida or not. If not that'd be a good first step.

Again, in normal automatic shifting, it won't go past 40 mph or 4000-4200 rpm until you ease off on the gas pedal. Re: Vida, while my Vida laptop still boots up the app, my old DICE unit no longer communicates between the car and the laptop, so I'm kinda stuck with my CarSoft i900 tester, which actually does pretty good at pulling true Volvo codes...more on this in a minute.

Post by **oragex** » 08 Nov 2017, 19:24

Just a wild guess but it seems related with the programing of the transmission or with some sensor that affects the transmission shifting (maybe the soeed sensor?). When the pedal is fully depressed the engine is supposed to go near 6000rpm before the transm would upshift.

mp5802 · Post by **mp5802** » 08 Nov 2017, 19:34

More Info:

Second and third road tests:

Both times, I had held the car at 40 mph and 4000 rpms for about 10-15 seconds. Both times, the system stored an ECM-280A (front O2 sensor) code. However, I don't think my i900 OBDII reader stored the condition value (signal too high, low, faulty or missing).

Both times, I cleared the codes.

I finally I did a third road test driving normally with normal throttle pressure, and as always, the car shifts perfectly through 5 gears, and no codes were stored, so I'm guessing that pushing the engine that hard without shifting at a prolonged 4000 rpm may just set an incidental O2 code.

I also wanted to know exactly what gear corresponds to 40 mph and 4000 rpm, so I switched to manual-shift mode and found that 2nd gear corresponds directly to this speed and rpm, so I believe now that it's the 2-3 upshift where the problem occurs. Again, I can take it past 4000 rpm and up to at least 5500 rpm if I keep it manually in 2nd gear.

mp5802 · Post by **mp5802** » 08 Nov 2017, 19:37

oragex wrote: 08 Nov 2017, 19:24 Just a wild guess but it seems related with the programing of the transmission or with some sensor that affects the transmission shifting (maybe the soeed sensor?). When the pedal is fully depressed the engine is supposed to go near 6000rpm before the transm would upshift.

Yes, I'd expect that to be the right way for it (or most cars) to operate. In normal driving, it shifts at much lower rpms, so the problem does not present itself under those conditions.

Post by **Rattnalle** » 08 Nov 2017, 23:51

If the issue is the same at 10 or 40 in different gears I'd go for engine trouble, not transmission. The low revs will then keep the transmission in the same gear because it's waiting for the right time to shift.

Is this at kick-down specifically or is it the same at close to full throttle?

To me it sounds like some part of the engine control system doesn't handle the full load situation well. Since you're getting an error code from the O2 sensor I'd at least try to get the actual parameters of the code. 4000 rpm for 10—15 s shouldn't set any kind of code. With the manual transmissions lower gearing you could spend hours at those revs if you do high speed highway driving.

mp5802 · Post by **mp5802** » 09 Nov 2017, 13:34

Rattnalle wrote: 08 Nov 2017, 23:51 If the issue is the same at 10 or 40 in different gears I'd go for engine trouble, not transmission. The low revs will then keep the transmission in the same gear because it's waiting for the right time to shift.

Is this at kick-down specifically or is it the same at close to full throttle?

To me it sounds like some part of the engine control system doesn't handle the full load situation well. Since you're getting an error code from the O2 sensor I'd at least try to get the actual parameters of the code. 4000 rpm for 10—15 s shouldn't set any kind of code. With the manual transmissions lower gearing you could spend hours at those revs if you do high speed highway driving.

It occurs almost always when I floor it at slow to medium speeds between 10-45ish mph, and the trans kicks down to 2nd. Under those conditions, it's like the car has a governor keeping it from going over 40mph & 4000 rpm. Again, if I use manual shift, I can hold it in 2nd and rev to at least 5500. Well, I need the car to work next week, so I think I'll take it in the following week to my reputable independent SVS (Sacramento Volvo Service) guys.

As an aside, I see these 2001-03ish V70s going for 2000-4000 on CL in my area. KBB lists the value of mine at for $2300-$3100, even with my low miles (101K). So, unless one just loves this car, a person has to really consider if expensive repairs are actually worth it now, don't you think?