M52B28 Running a little hot

[e30strokr]

yes temp fluctuates like that.... thats why we dont like the stock temp gauge it doenst tell you exactly whats going on.... I believe 220 and up is bad, I have run 210 while having "spirited driving"

change the coolant mix if possible, run some water wetter

[Northern]

Which gauge temp sender are you using? brown top M20? I don't think that's been mentioned.
Also try to find the part number of whichever thermostat you bought and see which temperature it is. I think 88deg is the correct but there are a few versions.

My cooling setup is very different, but with an 88degC Tstat + brown top M20 gauge temp sensor I sit somewhere around half while driving, and up to 3/4 idling in traffic before the fan kicks in.
ECU shows up to ~96 degC in traffic via romraider/INPA/whatever.
This is with an aluminum Z3M radiator and Spal 16" Pusher fan on an 88deg mercedes switch.

[Leonstt]

Hi guys,

I have been searching for this topic for quite sometime now. I havent found a definitive answer.
I swapped my M40 with M52B28 into a 1990 E30 sedan chassis a while ago and I have been keeping an eye on the coolant temp gauge.
I didnt trust the factory gauge, so I installed a VDO gauge to monitor more closely. So far, the temp has been hovering around 90-95 deg celcius (194-203F) depending on the traffic condition.
I did check using a diagnostic tool, my VDO is showing around 5 degrees celcius more than the ECU.

now, as the title of this post suggest, can anyone tell me what is the normal operating temperature for M52 engines? is there any factory standard?


thanks

[Northern]

I see up to 94 degrees through INPA or romraider logger in heavy traffic on a hot day, I think low/mid 90s is fairly normal with a stock 88deg tstat.

Worth mentioning this is with an aluminum Z3M rad and Spal 16" electric pusher fan.

[jsta1109]

I run the 88c thermostat on an S52, I see 90c - 100c, usually hangs somewhere in the middle. Also, top hose should read hottest which is probably why your gauge is showing slightly higher than the ECU.

[Drew325is]

On my alloy block M52B28 with 88c thermostat and stock M20 oil cooler I see 93-94oC at highway speeds pretty well regardless of ambient temperature. I'm running the A/C fan only and a very small 7" puller fan and in traffic I will see 96oC...anything higher I get nervous. It's not a daily so sitting in traffic is very rare. On the way to a track day once a small rock hit the oil cooler and I had to bypass it...it showed that the oil cooler makes a big difference in buffering the coolant temps, particular post-track session.

[Chilezen]

Why does it seem like I've seen this thread before...

Aha you've already posted about it. Why are you starting a new one?

https://www.r3vlimited.com/board/forum/e30-technical-forums/24v-engine-swaps/m50-52-s50-52/9949767-engine-temp

[Leonstt]

Why does it seem like I've seen this thread before...

Aha you've already posted about it. Why are you starting a new one?
https://www.r3vlimited.com/board/for...67-engine-temp

Oh sorry, I posted in several forums and I didn't bother to check. My bad.

Anyway, this is the latest development. I put a shroud around the visco fan. It helped a little bit. But on a longer and hot journey, temp started to creep up again. Any suggestions?

[Chilezen]

My dude, I'm in the same boat, I have a similar thread posted here.
What coolant do you have?
I'm going to drain my coolant and refill using a vacuum bleeder, to ensure they're aren't any bubbles hiding.

If I had the time and money, I would install an oil cooler kit, and wrap the headers with a good quality exhaust wrap.

[e30davie]

195F is 90C. Doesnt seem that high?

My m20 sits in around 90C according to the VDO temp guage. Are you using the right gauge sender for your oem gauge?

[Leonstt]

My dude, I'm in the same boat, I have a similar thread posted here.
What coolant do you have?
I'm going to drain my coolant and refill using a vacuum bleeder, to ensure they're aren't any bubbles hiding.

If I had the time and money, I would install an oil cooler kit, and wrap the headers with a good quality exhaust wrap.

I have Preston red coolant. As for header wtap, I was thinking of installing it but I don't think I can get it done without taking the headers off

[Leonstt]

195F is 90C. Doesnt seem that high?

My m20 sits in around 90C according to the VDO temp guage. Are you using the right gauge sender for your oem gauge?

I replaced the sender with the OEM BMW one in the original location

[2mAn]

now they are all merged lol

[Leonstt]

I bought a THINKDIAG scanner just to check what is going on. So here's what I've found. The ECU reads 88 deg Celsius (190F), the VDO is bang on 90 deg Celsius (around 194F), but on the dash shows past half way mark. 2 different readings. Is my dash gauge wrong?

[Northern]

It's not abnormal for the dash to sit a little high. A difference that small I wouldn't worry about.