2005 TRANSMISSION FAILING.. MODLE # A5S 390R YZ

[upallnight]

You have the "GM" transmission 5L40E so Dexron III was the original transmission fluid for the trans. Dexron is no longer available but Dexron VI is the new fluid being used. Unless you do the fluid change yourself, you will have to leave the X overnight with the mechanic/shop. The temp of the fluid can't exceed a certain temp if you want to get the correct fill level. Blame this stupid fill method on the engineers or bean counters at BMW for not including a dipstick for the trans, but coming up with this stupid procedure instead. You would probably like to have the filter replace at this time. Just remember a lot of old trans fluid is retained in the torque converter.

[FellowsheepTech]

Following...
My son's 2003 3.0i (230k) started throwing the same code (4th & 5th) and constantly going into limp mode not too long after I changed the driveshaft (after 2nd center bearing failure). I haven't had a lot of motivation to dig into it, but now thinking another fluid/filter service with the ATP AT-205. I've done the trans service twice before on it, but has been 50-60k since the last one. The first time I replaced center bearing I very carefully topped off the trans, so doubt it's just low.

BTW, we also had bank 1/2 codes a while back & it was due to gunked up CCV. I went the delete route following a post in another forum for E39. The "delete" was replacing the valve assembly with a PCV filter & various plugs/hose routing. Engine loved it!

[Rockit]

The mechanical ZF transmission are pretty good.... overall.

Try this first before you start doing mechanical stuff. Unplug all electrical connections to the trans and clean and lube them. If you live in a climate of salt or if someone pulled there boat in an out of the water with the car chances the connecters are corroded.

The main connector that plugs in to the natural safety switch was my problem and made mine go into limp mode. I was then told the celinoids in the trans were bad. Simple to clean it, you can crawl under and do this, try that first. The neutral safety switch is on the outside of the transmission.

And yeah 100k change the trans filter and oil. If you do this remember to start the car, leave it running and add the final quart. The Valvoline Maxlife AT is good to use, have it in mine.

Just remember everything on this truck is monitored my millivolts, one bad connector is all it takes, even the electric fan motor can through a code.

[crystalworks]

You'll have to get used to UAN c-bass. Very knowledgeable and usually helpful. But definitely gives out info with his nose in the air. Is what it is. There's one of two on every forum. Read past the "extra" stuff and the info in his posts is usually on point. As he is quick to point out.

[andrewwynn]

When the engine just reaches operating temp the mass of steel and aluminum will make for the transmission taking a good while to get up to the same temp if it's just acting as a heatsink. It wouldn't surprise me at all if the transmission would coincidentally hit 30-35 C right as the ECT hits 90c.

Of course every engine and every transmission will have different results, so unless you are *sure* that coincidence doesn't happen, the scientific approach is to do a measurement and find out.

My scanner will show transmission temp (I think the sensor is in the wiring loom setting in the oil pan), but I don't know if I can read the ECT at the same time.

As mentioned above, there is a very good chance that coincidentally the xm reaches 30-40C right when the coolant reaches 90.

I seem to recall reading 60c from transmission after driving around and the engine was full temp.

[crystalworks]

Just follow the tis, or ZF'/GM's fill procedure. Done it 5 times now, easy to follow as long as you can monitor trans temp.

I hang my foxwell out the left side door so I can see temp while filling on the floor. I do the cold fill, start it, top off, wait until 30*c (86*f), top off, cycle trans through gears (including manual mode) for 3 seconds each, get back under it and top off until fluid is dripping out when it hits 100-110*f. Done. That's for ZF trans but it sounds like the gm procedure is similar.

I think it will show ect simultaneously as trans temp. Going to be doing this procedure on our diesel e70 in the next week or so following transmission replacement. That's been a fun saga... Taking "while I'm in there" to new levels.

[Lost puppy]

I've received a lot of good advice concerning my failing transmission and I thank everyone for helping me. After everything I have checked with it I regret to say that I will have the transmission shop rebuild my transmission. I have gone to this shop for 30+ years and I've never had a problem with their work. Unfortunately it is going to cost me $3,500 - $4,500 😞

[upallnight]

Is a 2005 X5 even worth that kind of money?

[wpoll]

Originally Posted by upallnight

Is a 2005 X5 even worth that kind of money?

It is worth spending that if you get a few more years use from it. It's often not about "market value" but your own balance of "what's it worth to ME" and the cost of a suitable replacement....

I often see people junk a car because of a potential $3,000 repair bill, to then go and spend $10,000 on a replacement vehicle...

[Caryalon]

Originally Posted by upallnight

Is a 2005 X5 even worth that kind of money?

We have this discussion with customers every day.

If you buy a $4,000 car to rep!ace it, what's to say you won't be in the same position in another 3 months?

If you want to replace it with a low mileage used car, you're looking at $10 - 15,000. Used car prices are through the roof. Aside from that, finding a well cared for used car is not that easy, and a job all of its own. New cars are triple that price.

Often, if the car is in decent shape, on balance, it does make sense to fix it and get a few more years out of it.