CleanIsFast Journal: BMW X5 4.6iS

[X53Jay4.8is]

Originally Posted by CleanIsFast

Yesterday I took the 4.6 for a nice long (& spirited drive). What a machine....I eventually tried sport mode with manual shifting. This is the first time I've summed up the courage to try the manual shifting and to my surprise, it shifted flawless with no slipping, noises, etc from 1-2-3-4-5 and back down. Wondering If I just drive this way all the time and when coming to a stop just leave it in 2nd and see if the downshift lurch stays away.

At some point that Tranny will have to to come down to address its problems. But until then enjoy it in sport mode.

[CleanIsFast]

Does anyone know if the oil temp on the cluster is in *F while everything else is in *C? I was curious to see at what temperature the 2-1 lurch occurs and usually it's right before dead center (or "normal operating temperature"). But when I looked at the secret menu option #16 it's saying OELTEMP: 93*C? Why would the cluster say almost 210 (center). I did the conversion from *C to *F and it's pretty damn close which leads me to believe the cluster is in *F for oil temp.

[bcredliner]

Originally Posted by CleanIsFast

Does anyone know if the oil temp on the cluster is in *F while everything else is in *C? I was curious to see at what temperature the 2-1 lurch occurs and usually it's right before dead center (or "normal operating temperature"). But when I looked at the secret menu option #16 it's saying OELTEMP: 93*C? Why would the cluster say almost 210 (center). I did the conversion from *C to *F and it's pretty damn close which leads me to believe the cluster is in *F for oil temp.

Cluster is Fahrenheit. Don't know for sure why the conversion, have assumed it is converted in cluster for US vehicles.

[X5UK88]

Weird that they changed it, mine says 100 dead centre.

[CleanIsFast]

Originally Posted by X5UK88

Weird that they changed it, mine says 100 dead centre.

Well 100*C would be 212*F (dead center is about 210). So makes sense

So the 2-1 starts around 90*C

[bcredliner]

Am I confused? Are talking about engine oil temp and its relationship to how the transmission downshifts from second to first? If I am not confused, why do you think there is a connection between engine oil temp and 2-1 transmission lurch?

[CleanIsFast]

Originally Posted by bcredliner

Am I confused? Are talking about engine oil temp and its relationship to how the transmission downshifts from second to first? If I am not confused, why do you think there is a connection between engine oil temp and 2-1 transmission lurch?

Yes the engine temp.

Because the 2-1 downshift lurch is not present until right around "normal operating temp" in my case. Not sure why, but that's what I've noticed.

[X5UK88]

Originally Posted by CleanIsFast

Yes the engine temp.

Because the 2-1 downshift lurch is not present until right around "normal operating temp" in my case. Not sure why, but that's what I've noticed.

This is exactly the same for me, absolutely fine until full temp.

[bcredliner]

Originally Posted by CleanIsFast

Yes the engine temp.

Because the 2-1 downshift lurch is not present until right around "normal operating temp" in my case. Not sure why, but that's what I've noticed.

Correlation is that both heat up to the designed temperatures as the engine runs. The transmission temperature is independently managed. If the 2-1 lurch is temperature related it would be related to the temperature of the transmission fluid. If the transmission is overheating the usual symptom is that it begins to have a mind of its own, downshifts for no reason or stays in a particular gear.

Some have corrected 2-1 problem by changing the fluid, adding fluid because it is low or an EGS update. For others the problem was internal.

[CleanIsFast]

Originally Posted by X5UK88

This is exactly the same for me, absolutely fine until full temp.

Originally Posted by bcredliner

Correlation is that both heat up to the designed temperatures as the engine runs. The transmission temperature is independently managed. If the 2-1 lurch is temperature related it would be related to the temperature of the transmission fluid. If the transmission is overheating the usual symptom is that it begins to have a mind of its own, downshifts for no reason or stays in a particular gear.

Some have corrected 2-1 problem by changing the fluid, adding fluid because it is low or an EGS update. For others the problem was internal.

I have already replaced the transmission fluid and filter. About 2,000 miles ago. Symptoms is the same before and after.

Possibly a bad wire harness transmitting bad temp readings?