My GM auto transmission did not like Dexron VI

This was my third drain and fill. The first one was done with original ATF - Texaco ETL 8072B, second and third ones with Castrol Dex 6. I went with Dex 6 because that's what BMW now recommends for GM hydromatic transmissions.

The result is not so good. The car now is sluggish, with slow, soft, long shifts. It feels like something is holding it back, as if climbing up the hill. No slipping , but does not feel right at all. Not good.

The level is fine, I'm an expert at doing this by now having done it 3 times.

I'm planning to drain and fill again with different ATF.

Just a warning - be careful what you put in your AT.

Alex-

I have a tranny filter and gasket sitting in my trunk pretty much for the very reason that i cannot decide on which fluid to put in my GM transmission. There are so many different opinions out there and its very difficult to come to a decision. Do you know yet what fluid you plan on switching to? Or have you heard any positive results from other people with the GM tranny and the fluid theyve gone with? Any info would be greatly appreciated.

Actual GM Dexron 6 changed at 110000 miles. Current mileage 149000. No problems whatsoever. You probably have other issues with your tranny that a fluid change will not rectify

Originally Posted by Starless

This was my third drain and fill. The first one was done with original ATF - Texaco ETL 8072B, second and third ones with Castrol Dex 6. I went with Dex 6 because that's what BMW now recommends for GM hydromatic transmissions.

The result is not so good. The car now is sluggish, with slow, soft, long shifts. It feels like something is holding it back, as if climbing up the hill. No slipping , but does not feel right at all. Not good.

The level is fine, I'm an expert at doing this by now having done it 3 times.

I'm planning to drain and fill again with different ATF.

Just a warning - be careful what you put in your AT.

I doubt that is your transmission causing those symtoms SL. I believe you have a MAF or Throttle body or something else going on there. Dexron six is just another hydraulic fluid that meets previous spec. Worked fine on my daughters 2004 325ci.

However, did you ever do the memory reset? I read in this forum that you can turn the key on, engine off, depress gas pedal to the floor for 30 seconds and that resets the computer. So it doesn't drive like the person who was in it previously etc. I know that was probably you but would not hurt to try it.

I tried this on my wife's 323i and it seemed to get snappier afterward...i.e. slightly different shift points? not sure.

Dexron VI claims to be backward-compatible with all previous versions....maybe the current "mix" that`s in the trans is having a weird effect....each one has a different coefficient of friction, which could be causing your problem.

Do not know yet guys...

A couple of things. I did reset the transmission adaptations with INPA and that actually might have caused a slightly negative versus positive result. After 122K the valve body and other hardware is not the same as new, so who knows.

I've spent some time today doing diagnostics in INPA. Everything looks normal. All the solenoids activated normally, wires checked OK, pressure controllers fine.

I was afraid my torque converter was acting up, but driving with INPA monitoring the torque converter revealed no abnormalities. I mean I could see it turning ON and then OFF, so TCC clutch seems to function normally.

I replaced 5 quarts of Dex VI with Castrol Multi Vehicle ATF (advanced Dex III ATF) to change the viscosity of Dex VI but no change so far...

Will post an update when it happens. I also think that it
might be something different than my transmission, but what a coincidence!

Originally Posted by Fast Bob

Dexron VI claims to be backward-compatible with all previous versions....maybe the current "mix" that`s in the trans is having a weird effect....each one has a different coefficient of friction, which could be causing your problem.

That's what I think too, Bob! Dex VI is 40% thinner than Dex III too, so friction is the word...

Nuts, this is not good news. My car has 70k on it and I'm starting to think about a fluid change, but I don't know what to do about the fluid. This is not a job I feel I can tackle myself, so it's going to be a one-time change at an indy shop yet to be determined.

Question: from some searching, it seems that some Dex VI fluids like Valvoline are full synthetic, but Castrol may not be. Could that be the difference? Thoughts?

Originally Posted by jimvideopro

Nuts, this is not good news. My car has 70k on it and I'm starting to think about a fluid change, but I don't know what to do about the fluid. This is not a job I feel I can tackle myself, so it's going to be a one-time change at an indy shop yet to be determined.

OR, you could just sell the car to me and not have to worry about it. I'll give you $10.

(No Offense - I'm just being a jackass).

Dexron VI claims to be backward-compatible with all previous versions[img]*****************ca3[/img]

"Claims" being the operative word!

Originally Posted by halltristan

OR, you could just sell the car to me and not have to worry about it. I'll give you $10.

(No Offense - I'm just being a jackass).

Thankfully, working in corporate America, I have a high tolerance for that

Update. No change. I have replaced ALL Dex 6 with Castrol Import Multi Vehicle ATF. No change. Car still drives like crap. By that I mean a sluggish, non responsive throttle in other words loss of power. Transmission feels like it's shifting OK, nothing abnormal, no hesitation, no shutter, no slipping. I do not know what to do next. Change ATF to another brand? Change filter again? At this point I'm not sure if it's transmission (torque converter) related or not. No codes when scanned with INPA and Pa soft BMW scanner. Nothing. I just do not like to start throwing parts at it. So right now I'm doing nothing. But it's driving me crazy. All I know it all started after I changed the ATF with Castrol Dex6.

Can you tell me where you bought the oil pan gasket that goes around the top? Mine has 22 holes, and is metal, but for the life of me I cannot find the gasket for the oil pan. Mine broke off while I was doing my ATF change and I as well have put in Castrol import atf. I skipped the gasket part and just hooked everything back up. But I'm not sure if thats a smart idea now.

EDIT: 99 328i auto.

Originally Posted by Starless

Update. No change. I have replaced ALL Dex 6 with Castrol Import Multi Vehicle ATF. No change. Car still drives like crap. By that I mean a sluggish, non responsive throttle in other words loss of power. Transmission feels like it's shifting OK, nothing abnormal, no hesitation, no shutter, no slipping. I do not know what to do next. Change ATF to another brand? Change filter again? At this point I'm not sure if it's transmission (torque converter) related or not. No codes when scanned with INPA and Pa soft BMW scanner. Nothing. I just do not like to start throwing parts at it. So right now I'm doing nothing. But it's driving me crazy. All I know it all started after I changed the ATF with Castrol Dex6.

Drive it like you hate it and add 1/2 qt of B&M trick shift.

Originally Posted by Starless

Update. No change. I have replaced ALL Dex 6 with Castrol Import Multi Vehicle ATF. No change. Car still drives like crap. By that I mean a sluggish, non responsive throttle in other words loss of power. Transmission feels like it's shifting OK, nothing abnormal, no hesitation, no shutter, no slipping. I do not know what to do next. Change ATF to another brand? Change filter again? At this point I'm not sure if it's transmission (torque converter) related or not. No codes when scanned with INPA and Pa soft BMW scanner. Nothing. I just do not like to start throwing parts at it. So right now I'm doing nothing. But it's driving me crazy. All I know it all started after I changed the ATF with Castrol Dex6.

Alex,
Did you check to ensure you did not disconnect or contaminate one of the electrical connectors on the tranny? I know from reading in these forums there is at least one connector, if disconnected, loose, or contaminated will cause limp mode...so it may be possible something like that can cause an issue like you are dealing with? but easy enough to remove connectors, spray with CRC QD contact cleaner and reconnect.

Update. My transmission is back to normal after I drained all of the Castrol fluid and filled it in with German Pentosin ATF1, fully synthetic, golden color ATF. The power is back, shifts great.
Now my transmission is sealed for life. I'm not touching this pos anymore after all that work and waste of money on fluid. I'm glad I found the compatible fluid that restored the normal operation though.

Mine likes the factory fill. Ran into similar problems when I tried redline fluid in it. So it gets texaco when I change it. Cost more but it works flawless.

Originally Posted by crowz

Mine likes the factory fill. Ran into similar problems when I tried redline fluid in it. So it gets texaco when I change it. Cost more but it works flawless.

Did you get the texaco from a dealer or did you get it elsewhere?

Originally Posted by Starless

Update. My transmission is back to normal after I drained all of the Castrol fluid and filled it in with German Pentosin ATF1, fully synthetic, golden color ATF. The power is back, shifts great.
Now my transmission is sealed for life. I'm not touching this pos anymore after all that work and waste of money on fluid. I'm glad I found the compatible fluid that restored the normal operation though.

Glad to see this situation is finally fixed! Now you see why BMW won't touch the darn things!