Z4M Oil Cooling Solutions?

[Rsipad]

Got the M back on track last weekend. Went good, apart from the fact that the oil temp skyrocketed to 290F (~143C) after 6 laps and the engine went into limp mode. Water temps were not ideal but not terrible settling at 225F (107C). Ambient air temps were around 90F (~32C) when it happened. Saw that the S54 has a possibly restrictive oil cooler thermostat, which if bypassed can reduce temps by over 30F. Has anyone tried that and had any luck? Could I possibly have an issue with my cooling system with such a big difference in temperature between water and oil or does that seem normal?

 

[Ed Doe]

Jesus christ 143c that's bad.

I dunno if you've got a wider issue - I was at the ring a couple of weeks ago in 32C and my oil temps peaked at 120C-ish...

I'm not sure if removing the thermostat is going to resolve things if the hest isn't being dissipated in the cooler - I'd be checking the condition of your oil cooler first...

 

[BMWZ4MC]

Jesus christ 143c that's bad.

I dunno if you've got a wider issue - I was at the ring a couple of weeks ago in 32C and my oil temps peaked at 120C-ish...

I’d second that - I spent a day at Eastern Creek with the ambient temperature peaking at 37C and the maximum oil temperature was around 110C.
Eastern Creek is a large open track, which must aid cooling. The highest oil temperature I’ve ever seen was 120C at a UK airfield day in the summer.

 

[AndyBeech]

3rd the above. Done a few days at around 30c, especially last year, one was around 35c ambient and didn't go above 120c, usually hovered around 110c. That's with an original radiator and oil cooler on about 116k miles.

Changed to Fuchs Titan Race Pro oil instead of Castrol recently and haven't noticed much difference in temps either. Did a small-ish stint on Rowe oil as well which seems to be the rage with a lot of specialists at the moment and same temps again.

Pretty sure I remember reading somewhere shouldn't bypass the thermostat unless on a dedicated track only car, can't remember the details though.

 

[Ed Doe]

The issue with bypassing the thermostat is you have unregulated cooling of the oil - meaning it will take ages to get up to temperature, increasing cold wear, and could well overcool on motorways and low load high airflow situations.

None of that's an issue if it's a track car and you're getting it warm and then just pasting it the whole time.!

 

[Rsipad]

Thanks for all the feedback! Will take a look to see if there's any debris clogging up airflow to the oil cooler before doing anything else. I haven't touched the cooling system, and water temperature still rises quickly from cold so guessing no stuck thermostat there. Just noticed a months or two ago that oil temps like to rise when driving the car hard, even on backroads. In cruise it settles just above center like before.

The track I was at is extremely tight and doesn't really let the engine get much airflow. Talked with a guy in an e46 m3 that day and he was also having overheating issues, but with water temperature instead

 

[mmm-five]

I had it once at a very hot Nurburgring summer public day. Was fine when I started the first lap, got the orange warning about half-way around my second lap, and then went to red in the queue to exit the track...so had windows down and heating on full to remove some of the excess.

Did a few miles of off-track driving/coasting to give it time to cool down, but it took a long time to do so, and I only took it out for a lap at a time for the rest of the weekend, whilst monitoring temps via a code-reader.

That was when my car was on about 100,000 miles, and we did a full water/oil cooling system refresh when I got back (rads, coolers, water pump, thermostat, etc.)...and the following trip it was fine and was fine on every trip/track day before the car went into prolonged 'hibernation' at 160,00 miles.

 

[TomK]

got the orange warning about half-way around my second lap, and then went to red in the queue to exit the track...

Presumably that's for water temps as there is no oil temp warning light, only for pressure and level.
143 is high but it's within tolerance, the manual states not to exceed 150c and the castrol 10w60 is also good for that, however it will probably shear down to at least a 40 pretty quickly, so you should consider more regular oil changes.
FWIW I often see up to 135c these days which is higher than it used to be, I put that down to the FD change resulting in more time spent in the higher rpm range.

 

[mmm-five]

Presumably that's for water temps as there is no oil temp warning light, only for pressure and level.
143 is high but it's within tolerance, the manual states not to exceed 150c and the castrol 10w60 is also good for that, however it will probably shear down to at least a 40 pretty quickly, so you should consider more regular oil changes.
FWIW I often see up to 135c these days which is higher than it used to be, I put that down to the FD change resulting in more time spent in the higher rpm range.

Yes, the dash light is water temp, but there's also an oil temp gauge.

However we used a Snap-On diagnostics tool to show us live water and oil temps as we did some cooling down driving around the area and on some of the subsequent single laps, hence the decision to refresh everything on our return.