E46 330i powersteering overheating.

[silvabmdub]

I brought my stock 330i to a track day at Canaan motor club( a tight track) on Sunday 11/8/2020. The outside air temp reach a high of 70.

I lost power steering halfway through my 3rd 20 min session. No pump whine, no belt slippage that I could tell. I looked under the hood and found my power steering seemed to have overheated. I found about an ounce or so of fluid boiled out of the reservoir and spewed onto my airbox. When i took the cap off the reservoir, it was steaming.

I let it cool for 1.5 hours with the hood open, added some fluid, and then took it for a cool down drive. The power steering came back, so I took it out for another session. I lost power steering again, but this time, the pump was whining. The fluid seemed a hair low, but not low enough to cause pump whine. The pump, fluid, lines, and reservoir all have less than 5000 easy miles on them (before the track day). Im going to flush the fluid and seel if that helps.

Has anyone else experienced this?

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[aeronaut]

Not unusual for a little leakage from the P/S reservoir from a track day.
Very unusual for P/S fluid to be "steaming".
Quick thoughts:
Correct P/S fluid?
Anyway water got into the system?

I removed the cooling loop on the P/S on my track car, and measured temps of (metal) reservoir and steering box and measured 225F and 145F (respectively) on a 90+ deg day.

[NeilM]

Filter getting clogged in the reservoir, preventing full flow?

Neil

[silvabmdub]

I also asked guys on a facebook page. They are saying there is a check ball in the banjo bolt on the rack. Apparently the check ball and melt and block off the banjo bolt flow completely.

Im going to take the bolt out tonight to see if that is the case. Regardless of whether or not this caused my issue, in going to be cutting the cage that retains the ball in the bolt and reomove it.

I will update with my findings.

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[silvabmdub]

Filter getting clogged in the reservoir, preventing full flow?

Neil

I would hope not. That was replaced very recently. I will definitely check that out though.


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[silvabmdub]

Not unusual for a little leakage from the P/S reservoir from a track day.
Very unusual for P/S fluid to be "steaming".
Quick thoughts:
Correct P/S fluid?
Anyway water got into the system?

I removed the cooling loop on the P/S on my track car, and measured temps of (metal) reservoir and steering box and measured 225F and 145F (respectively) on a 90+ deg day.

This give me more reason to believe that the banjo bolt is block. If your fine with out the cooling loop on hot days, I should be fine with a cooling loop on a relatively cool day.

I highly doubt water made it into my power steering system. Im using the recommended ATF in PS system.



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[AJLM34A]

I installed a cooler from a full-sized Ford suv on my 94 E36 that is primally for HPDE with some weekend street use. I just got the car road worthy and with the cooler weather won't know if it will keep the temp down enough but it is only about $30 worth of parts and adds more fluid to the system.
Screen Shot 2020-11-10 at 3.46.38 PM.jpgScreen Shot 2020-11-10 at 3.46.20 PM.jpg

[silvabmdub]

I installed a cooler from a full-sized Ford suv on my 94 E36 that is primally for HPDE with some weekend street use. I just got the car road worthy and with the cooler weather won't know if it will keep the temp down enough but it is only about $30 worth of parts and adds more fluid to the system.
Screen Shot 2020-11-10 at 3.46.38 PM.jpgScreen Shot 2020-11-10 at 3.46.20 PM.jpg

That looks like an intelligent fix

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[silvabmdub]

*** UPDATE

After some helpful comments on facebook, I pulled both banjo bolts from the rack. The bolt with the 19mm head is the one with the check valve. I found a little piece of rubber of which i presume was part of a seal within the check valve. I believe this rubber jammed the valve closed and shut off the flow of fluid. I ground down the tip of the bolt and removed the insides. Im going to put it back it with fresh fluid and hope for the best.

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[ScotcH]

Thanks for the update ... I've actually never given that bolt a second thought. We run an electric pump with all AN hoses in the e46, but our e36 still has the OE pump (s54). Report back how it works without the guts ... maybe it's a needless complication and failure point for track cars!

[silvabmdub]

****UPDATE


After adding, and bleeding fresh fluid, power steering pump is still whining. I also found metal flakes. Im going to replace the pump.

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[silvabmdub]

Another update

I replaced the pump with and OEM pump, and used Redline D4 ATF. My PS still does not work.

I then replaced the reservoir to replace the PS filter. When i pulled my 2000 mile reservoir, it was completely clogged with rubber shavings. The new reservoir/filter did not help.

Where could these rubber shavings come from?

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[dominator293]

Not many other places it can come from besides the rack itself being faulty. I don't know enough about them to comment, but besides the reservoir, PS Pump, steering rack and cooling hoses/pipes, there's not much else it could be.

[silvabmdub]

**UPDATE

I figured I would post an update since I have resolved the problem, and so others can reference this in the future.

The hose that connects the reservoir to the suction side of the pump had collapsed in on itself. This restricted any fluid from getting to the pump. I never thought to check it since I had replaced only a few months before it failed.

For those interested, the hose that failed was manufactured by Rein.

[aeronaut]

Thanks for the update, nice catch!