transmission fluid flush?

[rattlenbang]

New owner here. I've gone through the forum looking for posts and didn't really find anything similar. My new-to-me '97 318i vert is absolutely immaculate, with 150,000 kilometers on the clock. It has been well maintained and drives like a dream, but one issue i've noticed is when i start it cold in the morning, it's somewhat reluctant to upshift (auto trans). Once it's gone through the gears a few times it's fine for the day. If I manually shift it through the gears once, it's also fine for the day.

Has anyone else experienced this and did they find a solution?

It seems to me the first place to go is fluid swap. One of the drive-thru oil change places here change tranny oil through the cooler lines - as the old fluid gets pumped out by the tranny, new fluid is injected through the other cooler line. Instead of the oil circulating through the cooler, it's replaced. Has anyone done this on their BMW? does it sound like a reasonable procedure?

Thanks for the help.

[Adijax]

Its normal , the trans needs to build up some oil pressure when cold wetter is present . I would not recommend to replace the oil or flush the trans .

[TCarlisle]

It's hard to say, but the shift points are at higher RPM's on mine when it is very cold. I've had the car since it had 35K miles and it has always been that way. No tranny issues at all. If this is what you are experiencing, it is normal ops. But if it is slipping or anything then you have issue.

A fluid and filter change is probably not a bad idea even if everything is working right, but don't have a shop flush it. They use high pressure and it has been theorized that pressure can dislodge stuff and make matters worse. I did a fluid/filter change on mine at 150K miles. Just follow the pelican parts article which is basically remove both pans to drain it, replace filter, use new gaskets to install the pans -- and when you install the smaller pan, prefill it with fluid at least halfway. Fill with new fluid. If you want to do an extra good job getting rid of the old, drain the fluid cooler on the radiator.

[rattlenbang]

Looks like I don't know what I'm talking about. When I drove off this afternoon I noticed the same upshift hesitation as this morning, but less obvious. When I first start up and leave, RPM heads to 3 gs before shifting, while normally it might at 2gs if the foot is light. Within a few blocks it settles down. Maybe it's nothing but with all the talk about how 'horrible' the BMW auto trannys sound on this forum, i'm a little paranoid about trouble.

[BiH55]

thats normal when its cold

[kaineb]

If your transmission has not been serviced regularly and you change the fluid you WILL be rebuilding it. Leave it alone.

[JESTERCYCLE]

I agree with the guys to a degree but we have a dealership and perform transmission flushes regularly using DEposit Control Systems "BG" products and have never had a failure. I just recently passed 100k on my 1998 328I and noticed sluggish shifts nothing crazy but not as good as it was. I did research on the transmission to see which I had this made my decision better because I also was skeptical on messing with it. I found my transmission is a GM Turbo hydromatic trans with dextron III fluid in it. This was good to me I am a GM guy and like these transmissions. At any rate, Instead of changing or flushing I drained a pint and added BG Automatic transmission additive which I have used in many of my own vehicles and a ton of cars at the dealership with awesome results. I immediately noticed improvement on my way home and is like new again. I plan to run a few thousand miles and then maybe to a filter change. Sorry for long winded post but felt it would help your decision. Give me a shout if you need info on the products. I would be careful using drive thru type servicing though for the reasons everyone is concerned of.

[E36 For Life]

I agree with the guys to a degree but we have a dealership and perform transmission flushes regularly using DEposit Control Systems "BG" products and have never had a failure. I just recently passed 100k on my 1998 328I and noticed sluggish shifts nothing crazy but not as good as it was. I did research on the transmission to see which I had this made my decision better because I also was skeptical on messing with it. I found my transmission is a GM Turbo hydromatic trans with dextron III fluid in it. This was good to me I am a GM guy and like these transmissions. At any rate, Instead of changing or flushing I drained a pint and added BG Automatic transmission additive which I have used in many of my own vehicles and a ton of cars at the dealership with awesome results. I immediately noticed improvement on my way home and is like new again. I plan to run a few thousand miles and then maybe to a filter change. Sorry for long winded post but felt it would help your decision. Give me a shout if you need info on the products. I would be careful using drive thru type servicing though for the reasons everyone is concerned of.

What type of dealership do you have that uses "BG" products? Yes the transmission is a GM 4L30E made in France.

[JESTERCYCLE]

Since 1991 Saturn, slowly coming to end sorry to say. But we also do a lot of used car recon as well as work on everything we sell.

[mt_goat]

I've followed this procedure on my 97 at about 80,000 miles: http://www.pelicanparts.com/BMW/tech...Fluid_Auto.htm

I refilled with Mobil 1 ATF.

The only problem is it only gets maybe half of the ATF changed. I've been to several places with a flush machine and none could do a full flush because of the way the ATF cooler lines don't disconnect, or they couldn't figure out how to disconnect them. I'm considering cutting one of the rubber sections of ATF cooler hose to do a flush and then reconnecting it together with a barb to barb connector and hose clamps. Another option is to just do several drain and refill cycles and that will get the majority of it changed. Drain and refills are a PITA with these cars because there is no dip stick for checking and refilling the ATF level.

I know BMW considers the ATF a lifetime fluid, but their idea of a lifetime is probably different than mine. I know they would rather me to buy a new car than keep this one.

BTW here's the flow direction of the ATF cooler lines for my 97 328i:

[JESTERCYCLE]

Exactly it is dextron III,it is not lifetime fluid, actually it should in a perfect world get changed every 15-30k it takes a ton of abuse as it is a hydraulic pump. And yes a pain to refill lol. The BG additive will free up those sticky valves in the valvebody causing your delayed shifts, fresh fluid will not. I also am not a fan of mixing synthetic with the original fluid just my opinion.

[mt_goat]

... I also am not a fan of mixing synthetic with the original fluid just my opinion.

Yeah, I didn't feel real good about it either. I had wanted to do a full flush after the pan drop and filter change to make it all synthetic, then ran into the problem of no one could do it. I will probably cut the rubber line now so it can be done.

[JESTERCYCLE]

My BG rep keeps telling me he has an adapter for the flush machine for my car but has never come through with it. Then I would do a synthetic flush. But all is good after the additive.

[rattlenbang]

Well, given that people say that this is normal behaviour, I think I'll let it alone. I like to do regular maintenance but it seems that there is disagreement whether this should even be done on an auto transmission.
It does seem strange to think about replacing the fluid every 30K - i recently sold my 68 galaxy 500, and i would bet that has never had a tranny fluid change. Certainly I've never done it on any of the 40+ vehicles I've owned and only a couple of times had a tranny problem.
I once had a 71 mercury marquis that was slow to go into gear when cold, and a 5 dollar bottle of seal softener saved the day. But maybe these newer electronic transmissions are more delicate...

[mt_goat]

My BG rep keeps telling me he has an adapter for the flush machine for my car but has never come through with it...

Yeah one local place kept telling that but it never happened. They are out of business now.

[JESTERCYCLE]

Pretty much why I just did the additive it works with the original fluid not some "shock" to the system, but trust me the fluid will fail and there is a reason for the changes in operation.

[motorwerks]

I recommend that everyone with an auto does a transmission flush. Lifetime fluid is absolutely not good for the lifetime of the vehicle. Most people do a trans flush when the car isn't shifting right. If you're at 150k, the car's not shifting right, and you decide to do a trans flush, don't blame the flush on your trans going out. It was already telling you that it was on its way out.

I've also found that most people seem to be to lazy to drive for awhile, and recheck the fluid levels. Even following the pelican DIY instructions you'll find that the trans will end up 1/2-1 quart low after a week of driving. It seems that it's often written off as the new fluid not gripping, and the owners keep driving until they burn their trans up. Recheck the fluid.

I absolutely agree with using the BG additive. I don't know what's in that stuff, but it smoothed out the shifting on my cargo van with 198,000 miles. I think it might be made out of unicorn piss...

Synthetic fluids are ok to mix with non synthetic fluids. They weren't 10 years ago, they are now. You can find this info on the manufacturers web sites.

also, don't forget to check your rear diff. fluid. Sometime hard shifting isn't a hard shift, but rather a slipping diff.

[95325i5sp]

as far as the the trans holding gears longer, its because of emisions regulations.the car is supposed to go into closed loop as soon as possible(theres actually time limits), and holding the gears longer while its cold gets the o2s and cats warmed up faster so it can. if i were you id let the car warm up a little more first. it also idles fast while warming up, to accomplish the same thing.as far as the trans flush, if your fluid has 150000m on it and aint red, i wouldnt mess with it.if it aint burnt up yet(orange/brown/black), then id say its worth it.

[JESTERCYCLE]

Good point on warm up too 95325i5sp, I am nuts about giving my car 5 minutes run time before I take off summer or winter.

[motorwerks]

Good point on warm up too 95325i5sp, I am nuts about giving my car 5 minutes run time before I take off summer or winter.

BMW recommends not warming up the cars by idling. You are supposed to give it 30 seconds, and drive keeping it under 3k until it's warm. (out of the blue)

[Mike WW]

Changing the fluid, regularly, is good for transmissions. BMW's lifetime fill policy was dictated by trying to keep service costs down, not by trying to get maximum life out of the transmission. I'm not a big fan of flushes, but absolutely pull the pans, clean them and change the filter. Then change the fluid in the pan ever 2nd or 3rd oil change. Yes it is a PITA, but it is what it is. When I did it in my 97 E39, the fluid was dirty, the filter was dirty and lots of stuff stuck to the magnets in the pan. Grit, however fine, isn't good in either hydraulic passages or between clutches, and in spite of the filter, you do get wear particles in the fluid. You're lucky, yours uses Dextron III, my 2000 528it uses some weird blend that is much more expensive and harder to get with much contradictary information about what fluid to use in it. And I hear BMW has scaled back "Lifetime" to now be 100K (mile) changes.

Sure it's lifetime, the (shortened) life of the transmission.

[JESTERCYCLE]

I guess another idea 10 peeps,10 answers.

I just changed out my diff fluid as well with synthetic, hoping to alleviate my shudder in the other post....didnt change that but now I know whats in it right.

[TCarlisle]

as far as the the trans holding gears longer, its because of emisions regulations.the car is supposed to go into closed loop as soon as possible(theres actually time limits), and holding the gears longer while its cold gets the o2s and cats warmed up faster so it can. if i were you id let the car warm up a little more first. it also idles fast while warming up, to accomplish the same thing.as far as the trans flush, if your fluid has 150000m on it and aint red, i wouldnt mess with it.if it aint burnt up yet(orange/brown/black), then id say its worth it.

This is a good explanation. Thanks!

As far as fluid/filter change and how good the auto tranny is in a BMW. As you are seeing this forum is full of opinions on the subject. Also these forums are notorious for being auto tranny bashing. Keep these things in mind when deciding what advice to follow.

Some of the recommendations are rather harsh, saying if you change fluid you will be rebuilding the tranny is a pretty bold statement. I can't tell you how your tranny will react to a fluid/filter change. Have people reported after changing fluid the tranny acts up? Sure. But that may have happened by coincidence (was going to happen anyways but the timing was with the fluid change) or the person underfilled the tranny or made some other error.

All I can tell you is what happened to mine. Owned the car since 35K miles and it was under warranty until 100K miles. Never had any tranny service. At 100K miles I wanted to have the tranny serviced and went to the delaer and started the job, but then got to the green sticker explaining not to change the "lifetime" fluid and they wouldn't do it. At about 150K miles after doing my own research and making my own decision, changed the fluid as per the pelican article using redline brand tranny fluid. No issues. That was 100K miles ago, so I recon it is time to do it again probably.

What it basically boils down to is how does the fluid hold up? Despite what BMW put on the green sticker, no fluid lasts a "lifetime", and all fluids break down overtime.Tranny fluid serves two purposes, well three actually..... it is a hydraulic fluid, so it needs to not compress so it can be a hydraulic fluid.It needs to lubricate, but it can't be too lubricative because it also needs to provide some grip so the clutches can grip without slipping. Oh, and it needs to clean debris and carry it to the filter. So I guess that is four things.

Anyways, any fluid that needs to do this many things, it doesn't take a rocket scientist to see that a fluid will eventually break down. It will get too dirty, decreasing it's ability to clean and increasing the friction..... it's lubricating properties will diminish further increasing the friction, etc.

So my recommendation is change it, simply because no fluid can last forever. At 150K miles and probably about a decade of use, your tranny has already exceeded what BMW considered the useful lifetime of the tranny.

Your engine oil doesn't need changed either and the oil is lifetime fluid -- if you want the lifetime of the engine to be about 30-40K miles. Yet we all change oil and expect our engines to last hundreds of thousands of miles, and they do. Can you find some stories on the net of people that "had to" rebuild an engine "because" they changed the fluid and filter? Yep. But we still change the fluid and filter in the engine, don't we?

Around here folks don't like the auto tranny to begin with, don't like that a GM manufactured part is installed in a German automobile, etc. and anytime someone has a story of an auto tranny failing those stories seem to spread like the flu.

[jamin325i]

love the gm auto in my 94 325i. it seems always in best gear for quick accel. unlike other autos i have driven requiring a wait to downshift. i believe it normal to upshift slow the first minute or two while warming.
drop/refill the 2-3 quarts at regular service 2 intervals ie +/- 35k miles. i did/do the pelican method every other service 2 interval. so i do the pelican tranny change method, but now, i would skip the small pan removal/ refill as it is messy and not worth the effort-and only do the larger pan clean, magnet clean, and filter change.
at 70k miles a heaping tablespoon of debris was on magnet so the filter was full and was past due to be changed.
so i would not flush my tranny to circulate this crap thru the entire system.
the full refill with pelican method is about 6-7 quarts. i don't know how much was left up in system prior to the full pelican method refill.
lastly, next time i will put my car on jackstands "level" so i i can check the fill level accurately after car warmup.

[rattlenbang]

After perusing here for quite awhile, I get that there is a real bias against auto trannys, and 20 years ago I probably would have agreed with them. Even now I don't really like them; they do the job kinda like the way a door keeps you in the car- it's there but you really don't think about it.
With the BMW it is different; the tranny is very crisp and responsive, even if it isn't in the sport setting. manuals are a lot of fun, but this auto is fun too!
The fact is that since owning this car, I've actually slowed down my driving because it's so much fun. It's easily the best driving vehicle I've ever own, so I prefer to take my time and enjoy the handling and feel. And an auto suits that somehow.
Despite what some people say on here, I see it as a luxury sport vehicle, not a true "sports car".

what I don't understand is this "level" business. If you don't happen to have a vehicle hoist or a pit, how the hell do you jack it up and keep the car level?