Powersteering fluid boils when driving on racecourse M5 E39 - The Unofficial BMW M5 Messageboard (m5board.com)

Qvarnis · 1st May 2003, 23:25

Just home from Nurburgring. After about 2 laps on the Ring the car started to boil the powersteering fluid. First warning was the powersteering cuts out in low rpm, second oil on window. Changed oil because it was ruined because of high temperature but the problem was there the whole week after 2 laps driving. Did 31 in total.

Is this common on the M5 E39 or is something wrong? If so, anyone who really knows what the problem is or is this fault common when driving really hard. One lap is 20 km+ and engineoil temp was passing 100 C so it's really hard driving.

When the "Sport" button for quicker respons in engine and harder powersteering was in i thought the car had the problem earlier than when driving in normal mode.

Regards/ Qvarnis
http://www.itsfun.nu
http://www.cityrace.nu/dempa/q

pmiranda · 2nd May 2003, 00:51

Strange, I've never had power steering fluid issues in all of my M5 driving.

The E36 M3 whines a bit from the power steering after hard driving, but never my 5'er.

Teutonaddict · 2nd May 2003, 06:13

Quote:

Originally posted by Qvarnis
Is this common on the M5 E39 or is something wrong? If so, anyone who really knows what the problem is or is this fault common when driving really hard.

Qvarnis-

I've noticed my power steering pump 'leaks' fluid out the top when I've tracked my M5. I've never noticed diminished function of the power steering, but then again most of the tracks I run are 3-4 km and not nearly as demanding on the vehicle as the Nordschlief!

I'd say that it's to be expected for a 1800 kg vehicle with recirculating ball steering when pushed on the track!

Good luck.
-Dave

stever · 2nd May 2003, 06:51

i've run at 100F on track and gone overtemp on water/oil, but no problem with steering

MIB · 2nd May 2003, 10:09

Hey Q, were you running your 20 Inch wheels?

kees · 2nd May 2003, 11:14

Never heard of this problem before affecting an M5. Are you sure your power steering fluid has been changed recently?

kees · 2nd May 2003, 11:16

BTW Qvarnis I heard you did very well at the Scuderia course - Best Rookie!

D/FW M5 · 2nd May 2003, 14:51

This is not an uncommon issue when tracking (not limited to BMWs, affects most cars), and there are fluids out there for power steering that will withstand higher temps. I'm sure on of the local race shops can recommend an appropriate high temp fluid.

Doug

John B · 2nd May 2003, 15:02

I also hav had the power steering fluid leaking out the top of the canister at a track day. It seems there is a lot of heat generated in there for some reason.

Stem · 2nd May 2003, 16:09

I've had "leaking " at the track. Not Boiling. I take a paper towel, twist it into a rope, and wrap it around the filler neck just under the cap. A twist will keep it in place. You then remove it when it has seepage, or the event is over.

I don't think this would work for a boilover, however!