Page 1 of 2 12 LastLast
Results 1 to 10 of 12
  1. #1
    Join Date
    Jan 2004
    Location
    East-Central Florida
    Posts
    444

    Question Erratic Shifting and Engine Temp

    I am experiencing a problem with the transmission. I’m not sure where the exact issue lies or if this problem is just a symptom of another system failing, but the end result is the transmission occasionally won’t upshift out of 2nd and sometimes 3rd gear or into overdrive. Here’s the particulars:

    On extremely warm days (mid to upper 90’s) and on trips over 200 miles (some shorter) the transmission won’t upshift properly – or else it will shift very erratically. This will occur in stop-and-go traffic or in rolling terrain – it’s not picky when it decides to do this. It’ll run up to 3,000 to 3,500 rpm (or higher) and I’ll still be doing only 35 to 40 mph. I should be doing 90 at that rpm level. While this is going on, the engine temperature will rapidly begin to climb to dangerous levels. I’ve never let it get to the “red zone” and if I pull over and stop, the temp will drop to near normal (slightly above normal).

    I don’t know if there’s a wheel speed sensor of some sort overheating and sending false or errant information to the transmission or if there’s some other cause. If I keep the engine rpm’s down to around 2,000, the temperature will hold just slightly above normal – any increase in rpm’s, the temp goes higher. Sometimes when I let off the gas while this is happening, the rpm’s will drop and it’ll shift and the temp will come down, sometimes not … and I’ll slow down as if it were a manual transmission left in a higher gear and not just coast like an automatic.

    Coolant level is normal and I had a complete transmission flush about 18 months ago. It has approx. 141,000 miles on it.

    Of course, when I took it to my independent mechanic, it was running fine and he could not find any error codes.

    Any ideas?

    PS - I'm leaving on a 300 mile trip in about 15 minutes ... wish me luck!
    Last edited by Bluegrass-XC; 07-17-2009 at 10:10 AM.
    Mike
    Bluegrass-XC
    (Somewhere on the Space Coast)

    2000 V70 SE Cross Country
    1987 Chevy K5 Blazer 4x4 (in Blazer Heaven)

    "Better to remain silent and be thought a fool -
    than to open your mouth and remove all doubt".

  2. #2
    Join Date
    Apr 2003
    Location
    Devon PA
    Posts
    11,409

    Default

    Yeah, it's probably shot
    (Sorry)

    You will be lucky to make it and return

  3. #3
    Join Date
    Jan 2004
    Location
    East-Central Florida
    Posts
    444

    Default

    JRL - you're wrong. I made it back just fine. Your lack of insight or ability to offer meaningful speculation and/or discussion on the causes of this mechanical puzzle is not appreciated. I'd rather not read negative posts or replies - only those which offer possible solutions to the stated problem.

    BTW - it turned over to 142,000 miles on the way back.
    Mike
    Bluegrass-XC
    (Somewhere on the Space Coast)

    2000 V70 SE Cross Country
    1987 Chevy K5 Blazer 4x4 (in Blazer Heaven)

    "Better to remain silent and be thought a fool -
    than to open your mouth and remove all doubt".

  4. #4
    Join Date
    Mar 2009
    Location
    San Diego/Flagstaff
    Posts
    352

    Default

    Maybe the thermostat/engine coolant temp sensor needs replacing. It may be that one of those is acting up in some way that is not allowing for effective cooling above a certain RPM. Transmissions act weird when they overheat but I don't think the transmission would overload the whole cooling system (could be wrong!).

    I would replace thermostat, ECT, and still do a good transmission flush or drain+fills. If it has been overheating, then the fluid may not be in good shape by now. Good luck!
    2000 V70XC 2.4L Turbo - Emerald Green -245,000 miles

  5. #5
    Join Date
    Jan 2004
    Location
    East-Central Florida
    Posts
    444

    Default

    Just returned from an 85 mile round trip drive into town - it shifted perfectly when it was supposed to and the engine temp stayed right where it belongs. I was doing 65 to 70 mph on the open road and stop and go - up to 45 mph in town. Outside air temperature started out in the low 80's and it was in the mid to upper 80's when I got home. I'm convinced that some sensor somewhere is overheating and causing the erratic shifting/temp increase. That just may be wishful thinking in hopes that it's nothing serious ($$-wise).

    Good suggestion ecbsykes ... I'm also of the opinion that once the tranny starts to overheat, the entire system is affected. I thought earlier that the transmission cooler may have something to do with it, but since I don't have any research material (VIDAS) I can't really look it up (study it) and try to make an educated guess as to what's causing this. I'm not one to just start throwing money at it (shotgun blast) in hopes of eventually hitting the problem. Wouldn't the diagnostic (code check) have flagged the engine temp sensor as faulty?
    Mike
    Bluegrass-XC
    (Somewhere on the Space Coast)

    2000 V70 SE Cross Country
    1987 Chevy K5 Blazer 4x4 (in Blazer Heaven)

    "Better to remain silent and be thought a fool -
    than to open your mouth and remove all doubt".

  6. #6
    Join Date
    Apr 2003
    Location
    Devon PA
    Posts
    11,409

    Default

    I didn't read where the temp is erratic, sorry!
    You probably need a new thermostat and possible acoolant temp sensor, (if you radiator is fine, no leaks and your coolant level is full)
    The computer can make the car do all sorts of nasty things when it's running hot.
    If this is/was the case, I would check the condition of the tranny fluid. If it got too hot, that CAN cause future issues.

  7. #7
    Join Date
    Jan 2004
    Location
    East-Central Florida
    Posts
    444

    Default

    ... hmmm - something to think about. When the tranny starts acting up, I don't always notice the temp gauge so I don't know what came first - the increase in engine temp or the erratic shifting. By the time I realize it's not shifting correctly (which doesn't take long), I'll look at the temp and it's dang near the critical point, then it'll upshift and the temp and rpm's will come down. Sometimes I'll just let off the gas - the rpm's will drop and it'll shift ... and the temp comes down again ... sometimes not.
    Mike
    Bluegrass-XC
    (Somewhere on the Space Coast)

    2000 V70 SE Cross Country
    1987 Chevy K5 Blazer 4x4 (in Blazer Heaven)

    "Better to remain silent and be thought a fool -
    than to open your mouth and remove all doubt".

  8. #8
    Join Date
    Jul 2009
    Location
    Rochester, MN
    Posts
    30

    Default

    Hi I noticed your comment that your tranny was shifting erratically AND your temp gauge would fluctuate?

    I am having issues with my tranny not wanting to shift out of 2nd into third unless I let off the gas. If you hold it under hard accelration the RPMs will quickly rise and fall but not change gears or accellerate unless i let off the gas.

    have you noticed your xc to be extremely slow accellerating too?

    I have not noticed my temp gauge flucuating I will look next time.

    I still dont know wahts wrong with my xc its at a volvo dealer and they will check it out Monday and let me konw. I hope its my ETM and not my TRANNY!!!

    Thanks! Good luck to you.

  9. #9
    Join Date
    Nov 2008
    Location
    Northern Canada
    Posts
    137

    Default

    I just had a similar symptom. It cost me $574.

    It was a faulty engine thermostat. Because the cooling system also cools the Transmission fluid. My engine overheated due to lack of coolant. It was exacerbated by the transmission refusing to shift (due to the high operating temp of the TM oil). And therefore it refused to shift, so the engine would not upshift.

    Upshot is this $35 part nearly cost me my engine. Dealer replaced, did a full coolant and TM flush.

    Replace your thermostat.

    One thing I've noticed is that the Temp gauge before this major catastrophic failure was a 30-40% warm. Now it is spot on half way.

    I remember reading a thread here that if you temp gauge is below 50% the thermostat may be stuck in the open position.

  10. #10
    Join Date
    Mar 2008
    Location
    MA
    Posts
    74

    Default

    a new thermostat+transmission fluid flush+coolant flush cost $574?

    ouch

    i hope they slapped on a new coolant temp sensor+gasket......

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •