The same wierd downshift, on the same turn, every morning.

[ApproachingZero]

There is a right turn about 100 yards from my apartment building each day that i take to work. Sometimes i have to wait for the green light, and other days i can go through. When i go through on a green light i turn the corner and get a strange downshift.

I know the 535i has terrible auto's, but this is the ONLY wierd thing this tranny does. Other than this, this tranny is as smooth as silk.

So basiclly i turn the corner, tap the gas, and there is a delay. It downshifts the motor revs, and then thump, and it is all over. I am then on my way with no problems.

I am having the fluid changed today, but is there any sensors that could screw with this? Maybe i am just being paraniod cause the tranny needs to warm up?

Thanks for your input.

[winfred]

sounds like it's low on fluid

[ApproachingZero]

sounds like it's low on fluid


Really, how so?

[genphreak]

Really, how so?When you go round the corner, you get a loss of pressure (perhaps).

ZF4HP22EHs are not terrible btw, they are excellent trannies, you just need to fix the forward A clutch pack (once they get really old).

You should make sure your fluid is fresh and that the filter is swapped out- debris will prewarn you of trouble/previous abuse. The Throttle Position Switch (TPS) needs to be accurately set also. :) Nick

[Ferret]

I'm having a similar thing happen in my 525TDS - sometimes when you stomp on the loud pedal, the whole car hesitates for a few seconds before thumping into gear.

Sometimes it locks the torque convertor in top gear with an audible 'thunk' too.

Finally, it makes a quiet very fluidic whine in first while pulling away, and can make it on deceleration too - I'm not to fussed about that noise though because the similar box in the 525i did it too...

Might have to get under it and check the level at some point.

EDIT : I'm wondering now if it's something to do with the optional extra oil cooler fitted behind the front grille... which wasnt there on the other auto 5 I owned...

[bmwrp8]

A friend of mine had that problem when cornering.Had it checked he was low on ATF and was dirty...Try changing your ATF (DextronII or III)and the transmission filter.Works Wonders;)

[ApproachingZero]

The flush is being done tommarow. They are doing the hole pan drop down and filter change. I just hope it is not too late, and that i opened a new can of worms......

[bmwrp8]

have you checked your tranny dipstick?whats the color of you ATF?

[ApproachingZero]

I checked the stick this past weekend while it was running. It looked a wee bit low, and the fluid was redish brown. After searching around this site i have two options after i do the full flush.

1. Continue driving like nothing ever happened

2. The transmission will slowely or quickly fail

At least i will be doing both in style ;)

[bmwrp8]

I checked the stick this past weekend while it was running. It looked a wee bit low, and the fluid was redish brown. After searching around this site i have two options after i do the full flush.

1. Continue driving like nothing ever happened

2. The transmission will slowely or quickly fail

At least i will be doing both in style ;)

hehehe true true:D but i suggest you change your ATF and filter...Mine was redish black before then I decided to Drain the ATF including the ATF in the Torque converter change it with the filter its almost 4months now shift is smoother than ever:p

[Blitzkrieg Bob]

will help smooth out the lumps

[RallyD]

I'm wondering now if it's something to do with the optional extra oil cooler fitted behind the front grille... which wasnt there on the other auto 5 I owned...

intercooler
http://www.realoem.com/bmw/diagrams/c/y/5.png

[Ferret]

intercooler
http://www.realoem.com/bmw/diagrams/c/y/5.png

Lol, not quite, it's not a gearbox oil cooler at all now you've got me looking, it's an engine oil cooler...

http://bmwfans.info/original/images/2506_p.png