Steering failure after 2~3 hot laps

[MT/RWD]

Here is the unsolved issue with my early 2008 e92 M3 steering..

After doing 2 to 3 hot lap the steering becomes heavy like there's no PS.

Lets start with the history.. after the first time i changed the PS pump and added bigger reservoir, then the things went well for two track days, the problem came again in the third track day in the 2nd session!!, i changed the pump, steering rack and added bigger steering cooler, then the problem came again in the next track day after 2 hot laps, took it to the garage and they found that there's some issues with the connection between the servotronic and the DME, so it's 99% from the DME "as they said", i paid 2k$+ and changed the dme... did 2 hot laps... and still nothing changed

Next step will be replacing all the steering hoses with new ones!

Any advices?..

[Patrón]

there seems to be a couple ps problems pop up lately. weird.

[warp10]

The pre 2011 cars had a different PS pump. Be sure that you got the right pump.

[MT/RWD]

Originally Posted by warp10

The pre 2011 cars had a different PS pump. Be sure that you got the right pump.

Yeah i got it wrong one time

[peter de la mare]

The servotronic sensor on the neck of the rack can be fussy. You can take it out and clean it, or replace it, it may or may not help.

If you've boiled the fluid a couple of times the plastic ball bearing in the banjo bolt can also start sticking, it's a $10 part, this should also be replaced. It'll also fill the bottom of the reservoir and filter with swarf., whole system needs flushing.

[Patrón]

Originally Posted by peter de la mare

The servotronic sensor on the neck of the rack can be fussy. You can take it out and clean it, or replace it, it may or may not help.

is it easy to access/remove or does the rack have to come off? i know where the connection is and can see the unit itself but was wondering if you've done it yourself. thanks.

[peter de la mare]

I did not do it myself, but it’s accessible from underneath. Rack does not need to come off.

[deansbimmer]

Originally Posted by peter de la mare

The servotronic sensor on the neck of the rack can be fussy. You can take it out and clean it, or replace it, it may or may not help.

If you've boiled the fluid a couple of times the plastic ball bearing in the banjo bolt can also start sticking, it's a $10 part, this should also be replaced. It'll also fill the bottom of the reservoir and filter with swarf., whole system needs flushing.

This is a post from someone who knows what's up. #1 suggestion.

[roastbeef]

Out of curiosity, what kind of course are you running on?
This shouldn't be happening, but I'm wondering if the course you're running is just overtly torturous to the steering system.

[MT/RWD]

Originally Posted by peter de la mare

The servotronic sensor on the neck of the rack can be fussy. You can take it out and clean it, or replace it, it may or may not help.

If you've boiled the fluid a couple of times the plastic ball bearing in the banjo bolt can also start sticking, it's a $10 part, this should also be replaced. It'll also fill the bottom of the reservoir and filter with swarf., whole system needs flushing.

Interesting.. will check it soon.. thanks a lot

[MT/RWD]

Originally Posted by roastbeef

Out of curiosity, what kind of course are you running on?
This shouldn't be happening, but I'm wondering if the course you're running is just overtly torturous to the steering system.

It's bahrain international circuit.. the F1 circuit it self

[slonik]

try to make same 2 laps, but revving up to 5k rpm only.
oem pulleys config ratio on steering pump is too high, and steering overheated quickly when you drive on 6-8k rpm for a long period.

[Hujan]

Originally Posted by peter de la mare

The servotronic sensor on the neck of the rack can be fussy. You can take it out and clean it, or replace it, it may or may not help.

If you've boiled the fluid a couple of times the plastic ball bearing in the banjo bolt can also start sticking, it's a $10 part, this should also be replaced. It'll also fill the bottom of the reservoir and filter with swarf., whole system needs flushing.

Hmmm. I spew PS fluid all the time. It's kind of ridiculous, actually. But my steering seems fine. It is messy, though. I wish someone would bring back that 3D Design expansion reservoir.

[peter de la mare]

Originally Posted by Hujan

Hmmm. I spew PS fluid all the time. It's kind of ridiculous, actually. But my steering seems fine. It is messy, though. I wish someone would bring back that 3D Design expansion reservoir.

I think it'll be ok if you top it up when the level gets too low, or flush it through completely. This is what I failed to do and two consecutive track days at the ring was enough to kill the pump dead. A sniff of the fluid left indicated that it wasn't at its best.

In hindsight, a flush with new fluid probably would have saved it.

[Patrón]

Originally Posted by Hujan

Hmmm. I spew PS fluid all the time. It's kind of ridiculous, actually. But my steering seems fine. It is messy, though. I wish someone would bring back that 3D Design expansion reservoir.

bimmerworld makes a nice aluminum one with AN fittings.

[peter de la mare]

These items, along with a new pump, should cure all steering issues.

[MT/RWD]

Originally Posted by peter de la mare

These items, along with a new pump, should cure all steering issues.

Already had all of these!! And nothing changed!!

Btw my steering is a bit heavier than the other M3s even when its cold!

[roastbeef]

if you have a cooler and that reservoir, something is wrong. do you have a pulley or anything? if you put the wrong pulley kit on, it might be possible that the belt is routed incorrectly. your power steering pump might also be dead.

[pbonsalb]

I was thinking of that same possibility—is the belt routing correct for the pump? Some underdrive pulleys require a pump pulley change or a different double sided belt. There may also be 2 different pumps used on early and late cars, one of which apparently spins in the reverse of the other.

[roastbeef]

yep, op has an '08. thats likely your problem man. belt is routed incorrectly or you have the wrong pump.

[MT/RWD]

Originally Posted by roastbeef

yep, op has an '08. thats likely your problem man. belt is routed incorrectly or you have the wrong pump.

I've ordered the wrong pump once and installed it.. it doesn't work at all.. then I ordered the right one and got all the belts from the dealer according to my chases #.. beleive me i became an expert with the PS system

I'm going to test it on the track tomorrow after changing 2 hydrolic hoses which contains valves.. and those were the only unchanged parts in whole system.. pray for me please!!

[Patrón]

Originally Posted by MT/RWD

I've ordered the wrong pump once and installed it.. it doesn't work at all.. then I ordered the right one and got all the belts from the dealer according to my chases #.. beleive me i became an expert with the PS system

I'm going to test it on the track tomorrow after changing 2 hydrolic hoses which contains valves.. and those were the only unchanged parts in whole system.. pray for me please!!

can you show us what hoses? I wonder if lines without the valves would be an upgrade?