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Folks,
Need advice on an unfixable problem:
Original owner, 5-cyl, non-turbo, 85,000 mi, FWD, wagon.
Worked on by our trusted mechanic.
No engine or transmission codes have ever appeared.
PROBLEM DESCRIPTION:
All events occurred while going up slight inclines on surface streets or freeways.
0746 (Time): Engine start. A/C off. 59F.
0748: 2000 rpm, 20 mph. Slow acceleration in 2nd gear from stop sign and car hesitates slightly with loss of acceleration.
0752: Car water temp normal.
0809: 3000 rpm, 75 mph. As soon as a slight uphill section is reached, the car smission problem started to appear. On slight incline or when on freeway: carstarts to surge a little back and forth (as if its slipping the clutch or power is being added and lost).
0811: 2100-2500 rpm, 2nd gear, onramp. Car surges a little in 2nd gear.
0813: 3100 rpm, 77 mph. While on uphill section, the car shudders slightly and surges back and forth a little.
0814: Same again.
0815: Same again.
0820: Same again.
0822: Depressed accelerator while on uphill section to maintain speed and car car shudders slightly and surges back and forth a little.
0827: 2000 rpm, 20 mph. Accelerating in 2nd gear, car hestitates, surges back and forth moderately, rpm goes from 2300 to 4000 rpm immediately, and then drops into 3rd gear at about 2000 rpm at 35 mph.
0830: In one second: Rpm goes up from 3100 to 4100, car slows, rpm return to 3100 with a clunk, as if trans went from neutral to drive.
Mechanic says it's a bad trans.
1st problems appeared early 2007 and got worse over six months to the poitn we needed to fix it. Trans replaced Sep 2007. 1st week everything OK, but then the hesitation problem reappeared and after a few weeks all appeared problems and were almost identical to the 1st transmission's. Mechanic reset trans computer back to original settings. Problems went away for about a week and then gradually returned. 2nd trans replaced Nov 2007. 3rd trans has exactly same scenario as 2nd trans. Currently, with 3rd trans in car for the 10 days now, having hesitations which are occurring more often day by day.
It seems to me its not a trans problem but something that controls the trans. Trans computer? With no codes, my mechanic does not want to change it. Anything else??
Hope you have a good suggestion because otherwise, it's off to the dealer.
Thanx much
GRG
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My 850's tranny hunted for gears when going uphill (took me a while to duplicate the problem to show dealer). I could feel the tranny "choke" in and out of the gears. No code logged at all. In highway (freeway) speed, torque converter unlock and rpm raised to 4k or so. Took the car to dealer after 2 days. Fluid was black and needed a "new" tranny to fix converter unlock issue. Replacement tranny still "choke" to hunt for gears at uphill road. Dealer tech. test drove with me to duplicate the problem. They could not find anything wrong with the replacement tranny. I asked dealer to try a suggestion from this board back then (1999), TPS replacement. A new TPS fixed the gear hunting issue on uphill road. That saved the replacement tranny.
The replacement tranny worked for a while then it started to leak from the tranny casing glue area. Dealer put in 3rd tranny and up to now. 3rd tranny has been running for about 140k miles, so far so good with fluid flush every 30k miles.
Hope this may help.
Ching-Ho Cheng
--
1995 855 NA, Bilstein Strut & Shocks, Volvo Protective Grill, K&N Filter, E-Code Lens, ClearCorner Light, Alpine CD-Changer, AutoDim RearView Mirror, 6000K HID
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This sounds very much like my problem. I'll tell my mechanic. Can you tell me what is the "TPS"?
Thanx!
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TPS is throttle position sensor. It is located a bit below the throttle body. Not too expensive to replace and worth to try.
Good luck.
Ching-Ho Cheng
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1995 855 NA, Bilstein Strut & Shocks, Volvo Protective Grill, K&N Filter, E-Code Lens, ClearCorner Light, Alpine CD-Changer, AutoDim RearView Mirror, 6000K HID
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I just read your post an also wonder if it really is a tranny problem. If it only happened while changing gears or under full throttle, OK, but not at light throttle.
Has the throttle body been cleaned? Do you have a clogged vacuum line? And why did the car start off in 2nd from a stop sign?
If the tranny fails, it will post a code. If it is a fuel delivery problem, codes may not appear. It would be worth going to a Volvo mechanic that has a Volvo scan tool to check out the TCU and the ECU.
Klaus
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The 164 has a new home, all I am left with are a 95 854T and a 98 V70R :)
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In response to the last two posts:
My mechanic says that he has seen many 740's with antifreeze in the trans and so is familiar with the problem. As he has taken the trans apart three times now and checked the fluid, he says there was definitely no antifreeze in it.
Regarding codes, no codes for the engine or trans have ever appeared. However, he still is interested in checking the engine, e.g., injectors, throttle body, and anything else that might cause a hesitation.
Regarding 2nd gear acceleration, my original post meant to say the the car had gone from 1st to 2nd when the hesitation occurred, rather than starting from a stop in 2nd.
There has been an improvement in driving the last few days. No problems at all. This is very confusing. I think the next step will be to have a thorough engine check. BTW a year ago we had an intermittently-stuck butterfly valve with no code that caused stalling and a major headache.
Thanx for you help. Any other ideas are definitely welcome.
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posted by
someone claiming to be fixit2003
on
Tue Nov 27 06:11 CST 2007 [ RELATED]
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Has the mechanic checked the fluid? You could have a small internal leak in the cooler/radiator allowing antifreez and tranny fluid to mix. Tranny fluid in the engine is no big deal. Antifreeze in the tranny is another story.
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Good suggestion. I'll have it checked asap.
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posted by
someone claiming to be Tim
on
Sun Nov 25 01:34 CST 2007 [ RELATED]
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Not unfixable. You might be headed to a dealer.
Are the transmissions rebuilt or used? Did the mechanic change the torque converter?
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Transmissions are rebuilt, the same source as the Volvo dealers. No, the torque converter hasn't been mentioned. Can you explain how it would produce the symptoms, primarily that the trans is OK for a week or so and then problems appear and gradually get worse?
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I doubt if the problem is unfixable.
I think your mechanic might be unfixable.
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I would say it's not the transmission!
Are there any Engine or Transmission codes?
I would connect a scanner and read the parameters of the transmission and engine to see what the sensor signals are doing.
Is he resetting the transmission by disconnecting the battery? Not a good idea if true!
If so, he is also resetting the engine computer, so you can't tell which is creating the problem. Make sure just the transmission computer is reset, or just the engine computer.
He may be a good mechanic, but you need to get someone else to look at this.
B
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When the 1st trans was in the car, there were no eng or trans codes. After the 2nd trans was installed, also no codes. After a week on the 2nd trans, problems appeared and there were still no codes. This was when the mechanic reset the trans computer back to 1996 settings. Now on the 3rd, same story, no codes.
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These were the problems I loved to deal with. Wish I could drive it!
Are you sure that the transmission is the problem? Is it possible the engine performance is the issue?
If you and the mechanic really think the trans. is the issue, then you may be having problems with the control module.
Or, a shared sensor between the engine and transmission. Like the throttle position sensor or vehicle speed sensor. Is the ABS light on?
B
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These were the problems I loved to deal with. Wish I could drive it! ME TOO.
Are you sure that the transmission is the problem? Is it possible the engine performance is the issue? IT ACTS MOSTLY LIKE A TRANS PROBLEM BUT IT ALSO ACTS LIKE A FUEL DELIVERY/IGNITION PROBEM, E.G., A MINOR LOSS OF POWER WHEN ACCELERATING PAST 2100 RPM.
If you and the mechanic really think the trans. is the issue, then you may be having problems with the control module. IF YOU'RE FERERRING TO THE TRANS COMPUTER, NO CODES APPEARED. HE DOESN'T THINK THAT'S THE PROBLEM BUT.........MAYBE. HOW CAN ANYONE KNOW IT'S THE TRANS COMPUTER WITHOUT CODES?
Or, a shared sensor between the engine and transmission. Like the throttle position sensor or vehicle speed sensor. Is the ABS light on? ABS WAS ON DURING THE PERIOD OF ALL THIS TRANS TROUBLE. BUT HE IDENTIFIED A BAD ABS CONTROL UNIT, WHICH WAS REPLACED, AND THE LIGHT WENT OUT. WHAT'S THE CONNECTION BETWEEN ABS AND THIS? I'LL HAVE THE SENSORS CHECKED. THANX.
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