S70 wagon suddenly lost acceleration control on highway, seems like in neutral
#1
03-01-2019, 10:26 AM
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S70 wagon suddenly lost acceleration control on highway, seems like in neutral
I've scoured forums for 2 weeks. I just bought this 01 S70 3.5 weeks ago. Up until this incident had no issues with idling, or any slipping or hard shifts. I was driving at cruising speed on the highway, and suddenly the tach revved like crazy, I took my foot of pedal and it slowed down, put foot on gas and just revved, no response. I managed to get off highway, put in park. Turned it off and on, put foot on brake, and shifted into drive, it was almost like it was in neutral, tach revved, wouldn't move, and started rolling backwards as I was on a slight incline. If I turn on and off several bazillion times, it will occasionally go into drive or reverse, but as soon as brake is applied, or put into another gear, will not respond and again is as if it is neutral. One general scanner said P0740 Torque Converter Clutch Circuit open, and a different mechanic said his said the 'torque converter wasn't receiving pressure' and I needed a new transmission. Again I've not had any skipping or hard shifting. I've read everything from it possibly being the Throttle control, a faulty solenoid etc etc. Can anyone help? I'm having to quit my job as I have to transportation! The mechanics I talk to automatically go to 'you need a new transmission', generally I feel that's due greatly to the fact that I'm a woman, but I used to drive a '98 Dodge Cummings with tranny issues, so I know what that feels like! lol
#2
03-01-2019, 10:36 AM
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It is not terribly normal to have total sudden transmission failure, so the diagnosis of the exact cause is not obvious. However, it's obviously not engine related.
Anybody who says "you need a new transmission" is pretty smart in this case to say so. You do.
Now, that said, it would be right to at least check the fluid level, right? If a transmission has no oil in it, then it'll perform like you are seeing. But it's hard to get to that point suddenly.
It's also reasonable to at least look at the final drive as a potential break point, because some of that is outside the transmission and you can see it.. We've had a couple of people drop in here who had a car that wouldn't hold still in park, which means something hard in the final drive broke. Generally, they never come back to say what exactly broke in the final drive. If your car will hold in park, then this is hopeless and you should ignore me here.
If that doesn't do it, when the transmission is out and in a million pieces, the exact cause will be evident.
Anybody who says "you need a new transmission" is pretty smart in this case to say so. You do.
Now, that said, it would be right to at least check the fluid level, right? If a transmission has no oil in it, then it'll perform like you are seeing. But it's hard to get to that point suddenly.
It's also reasonable to at least look at the final drive as a potential break point, because some of that is outside the transmission and you can see it.. We've had a couple of people drop in here who had a car that wouldn't hold still in park, which means something hard in the final drive broke. Generally, they never come back to say what exactly broke in the final drive. If your car will hold in park, then this is hopeless and you should ignore me here.
If that doesn't do it, when the transmission is out and in a million pieces, the exact cause will be evident.
#3
03-01-2019, 11:45 AM
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#4
03-01-2019, 04:18 PM
#5
03-02-2019, 09:54 AM
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You know it's also possible that all the flywheel to tc bolts sheared off, but I think real testing would reveal that. The input speed sensor would see that.
About park, I was just saying that there were a couple of people who posted here that the car rolled away in park. Park holds the final drive still, and it's mechanical. So if the car rolls away, you have a narrowed idea of where the damage occurred.
About park, I was just saying that there were a couple of people who posted here that the car rolled away in park. Park holds the final drive still, and it's mechanical. So if the car rolls away, you have a narrowed idea of where the damage occurred.
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