Is there a automatic transmission fluid level sensor?
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Is there a automatic transmission fluid level sensor?
We had an accident in our A6 and its been shifting horribly ever since. I think they had to replace the trans oil cooler so it may be low on fluid.
When cold it shifts hard and when coming to a stop and down shifting into 1st it seems to hold onto 2nd and then clunk into 1st dropping the RPM's noticeably. It actually stalled on me twice today in traffic while coming to a stop. 2002 A6 Avant 3.0. When warm it generally works better.
The "auto rebuild specialist" I talked to said that the computer would tell me if the fluid was low. VAG-COM shows no codes but something definitely is not right here. I've read here too that when changing or filling the trans fluid you actually have to put it in gear and watch the temperatures to make sure that the fluid level gets topped off at the right level. I have no idea what method they actually used when putting it back together, and of course the problem goes away when they drive it.
Any ideas?
When cold it shifts hard and when coming to a stop and down shifting into 1st it seems to hold onto 2nd and then clunk into 1st dropping the RPM's noticeably. It actually stalled on me twice today in traffic while coming to a stop. 2002 A6 Avant 3.0. When warm it generally works better.
The "auto rebuild specialist" I talked to said that the computer would tell me if the fluid was low. VAG-COM shows no codes but something definitely is not right here. I've read here too that when changing or filling the trans fluid you actually have to put it in gear and watch the temperatures to make sure that the fluid level gets topped off at the right level. I have no idea what method they actually used when putting it back together, and of course the problem goes away when they drive it.
Any ideas?
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Yeah... Fluid level is very important with these transmissions.
I'm not sure if there is a sensor or not, so it would be a good idea to check the level manually. Mine has similar symptoms on occasion, and I believe it is due to a low fluid level.
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So not the Torque Converter?
So it's not likely to be a torque converter problem? It doesn't feel like its slipping, and only seems to exhibit when its cold. My theory is that when its warm the fluid expands and is enough to let it shift ok. Its almost like its not unlocking the TC while shifting or locking when it shouldn't. I.e. after coming to a stop it drops to 1st and lurches forward and or drops RPM or kills the engine.
They also supposedly replaced some sensor on the transmission that lets the ECU know what gear the car is in or what speed the output is spinning. That seemed to help for a few days but the symptoms are now to a point where the wife won't drive the car anymore.
They also supposedly replaced some sensor on the transmission that lets the ECU know what gear the car is in or what speed the output is spinning. That seemed to help for a few days but the symptoms are now to a point where the wife won't drive the car anymore.
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Could be. Honestly they sound like they are clueless.
I would have someone else look for codes.
A torque converter issue generally throws a code. Have someone who knows what they are doing and has the correct diagnostic software look at it.
I hope you haven't been driving it too long.
A torque converter issue generally throws a code. Have someone who knows what they are doing and has the correct diagnostic software look at it.
I hope you haven't been driving it too long.
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My best guess is no, here's why
When you do a fluid service, you can use VAG-COM to measure the temperature, but the only way to get the level right is to put the car on a lift and pump fluid up and over a fill lip, until it runs back down.
You have to go through a specified routine to get the fluid warm but not too hot.
If VAG-COM could read the info, all this would not be so involved.
It is also obviously very dependent on temperature.
Grant
You have to go through a specified routine to get the fluid warm but not too hot.
If VAG-COM could read the info, all this would not be so involved.
It is also obviously very dependent on temperature.
Grant
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Specific Routine as in...
The rebuild shop did a very good job overall but is this routine something that is specific to these cars? It sounds like this could this have easily been messed up. Do you need to put the car in gear while running and filling the trans fluid as I've seen in other posts?
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Needs to be running, in Park, and temp must be spot on (can't remember
the exact temp though.) There is a tech article somewhere on how to change the trans fluid. It's for an A8, but the procedure should be similar.
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confirmed this procedure with the dealership
The service tech said something like 62 or 65 F but he didn't sound sure. I'm going to try an get the rebuild shop to check this again and hopefully do it correctly.
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SRLY? They haven't fixed it yet and you are going to bring it back? Run, Forest, run!
Go somewhere that can fix the car! Get someone local to read the codes with VAG-COM!
To check, elevate the car keeping it level. Loosen the fill plug but do not remove it. Start the car from dead cold. Set VAG-COM up to monitor fluid temp. Fill trans until fluid runs out. Let car come up to temp while fluid trickles out the fill hole. When temp is in spec, install and tighten the plug.
To check, elevate the car keeping it level. Loosen the fill plug but do not remove it. Start the car from dead cold. Set VAG-COM up to monitor fluid temp. Fill trans until fluid runs out. Let car come up to temp while fluid trickles out the fill hole. When temp is in spec, install and tighten the plug.