M52B28 Running a little hot

[Leonstt]

Hi guys,

I'm running into a little issue after my swap. I live in Indonesia where the ambient temperature is always between 85-95 Deg F all day and with stop and go traffic condition.
My cooling system setup at the moment is:

• New E36 323i radiator
• new water pump for M52B28
• 161 deg F thermostat
• all new hoses and pipes
• Slightly modified fan shroud
• 16 inch pusher fan (on all the time)
• stock clutch fan

I drove my car yesterday (ambient temp around 90 Deg F) in stop and go traffic with AC on and noticed that the temp gauge is creeping up to about 3/4. And my VDO gauge indicate around 195 deg F (sender is located at the top rad hose).
I would come down when I increase the speed. It has been going on like this since I finished the swap around a year ago.
Any one can enlighten me what cause the temp to fluctuates? I did a bit of looking around and found that my AC condenser, which is located at the front of the rad, the fins are quite mangled. Could this be the culprit? I'm at lost tbh.

[Leonstt]

Hi guys, I have a question regarding my engine temperature after a M52B28 swapping my 1990 E30 sedan. I just finished the swap process a few months ago and my setup is as follow. I use the same engine mount location as the factory M40 engine. But for the mount I use E34 M50 mount. I'm using E36 cooling system and moved the reservoir to where the battery was. I changed the water pump and thermostat to new units. Also I replaced the fan to electric and another behind the grille to draw air. These fans I keep them running all the time. As you can see in the picture, because I'm using the factory engine mount location, the front of the engine is very close to the rad (prolly about a fingers width) Now, I noticed that when I'm stuck in traffic on a hot day my temp gauge is hovering between half and 3/4. Highest was 3/4 and never go above that. Not sure if this is normal but I think it's a bit on a high side. Oh and I live in Indonesia, so the air temp is around 30-35 degrees celcius. So it is pretty hot especially when stuck in traffic. I have AC in my car too I checked that my coolant is full, thermostat is working nicely, fans are on. Given my environment, is it normal for my engine temp to go above half? What else should I check? Sent from my SM-P205 using Tapatalk

[ForcedFirebird]

Find the real temperature, the gauges are just a guide at best and are often inaccurate after all these years. My first e30 many years ago would sit at 3/4 on the gauge, but putting a thermometer on the thermostat housing showed normal.

The stock thermostat opens at 92°c and the e30 auxiliary fan doesn't come on until 91°c for the low setting and 99°c high, if you are still using the stock switch on the side of the radiator.

[roguetoaster]

Might be worth bleeding the coolant system again, maybe even elevate the overflow tank as high as you can to help eliminate air pockets while bleeding. Also, quite a bit of your radiator is not being covered by a fan or ducting for a fan, so you may have a simple airflow issue, even with both fans rigged to be always on.

[Leonstt]

Find the real temperature, the gauges are just a guide at best and are often inaccurate after all these years. My first e30 many years ago would sit at 3/4 on the gauge, but putting a thermometer on the thermostat housing showed normal. The stock thermostat opens at 92°c and the e30 auxiliary fan doesn't come on until 91°c for the low setting and 99°c high, if you are still using the stock switch on the side of the radiator.

You mean using infra red type thermometer? Sent from my SM-P205 using Tapatalk

[Leonstt]

Might be worth bleeding the coolant system again, maybe even elevate the overflow tank as high as you can to help eliminate air pockets while bleeding. Also, quite a bit of your radiator is not being covered by a fan or ducting for a fan, so you may have a simple airflow issue, even with both fans rigged to be always on.

The coolant has been bled multiple times and I haven't opened the cap since I bled the system, which was done 2 weeks ago. I'm thinking of making a shroud on the engine side of the rad. But might hit a pulley since the engine sits so close the the rad Sent from my SM-P205 using Tapatalk

[Leonstt]

Just wondering if it would be better to fit 2 smaller fans than 1 big fan like I have currently. Any thoughts? Sent from my SM-N770F using Tapatalk

[roguetoaster]

Better, not really, but not worse either. Just whatever fits the area you need and pulls plenty of air.

[Leonstt]

Now, deviate a bit from engine cooling, I notice that the engine bay temperature is very high. Especially after a relatively long drive. I feel that on the header side is super hot. I mean as soon as I open the hood, I feel a rush of hot air. The intake side not so much.
So I'm thinking of wrapping my header with header wrap. Anyone have any experience with this? what is the downside of wrapping headers? any risk of damaging the headers and lower engine block?

Note: my header is OEM M52 header with slightly modifed lower flange to fit in my E30 chassis

[roguetoaster]

Engine bay heat just seems to be a feature of the M5x engine family. Not sure if it's just a feature of a more modern engine with higher efficiency/higher combustion temperatures.

In any case, it shouldn't hurt anything, and wrap, applied correctly, may lower bay temperatures slightly, but it's probably not worth the hassle.

[Leonstt]

Engine bay heat just seems to be a feature of the M5x engine family. Not sure if it's just a feature of a more modern engine with higher efficiency/higher combustion temperatures. In any case, it shouldn't hurt anything, and wrap, applied correctly, may lower bay temperatures slightly, but it's probably not worth the hassle.

I think lowering engine bay temp is helpful since the ambient temp here in Indonesia is always above 32 deg celcius. One other question I have is, is it true that header wrap when applied to OEM header with no coating can cause it to rust much sooner? Sent from my SM-P205 using Tapatalk

[Leonstt]

Guys, I'm thinking of making a shroud for my rad on the pull side of the fan. But as you can see the position of my fan is not in the middle due to space constraints, if I shifted the fan to the right, it would hit the AC pulley. Now my question is, would it make any difference if I make a custom shroud that covers the whole puller side of my rad? Will the effect be even worse than my current setup? Sent from my SM-N770F using Tapatalk

[jsta1109]

With an 88c thermostat my gauge used to sit at 3/4, I just forced it back to the 12o'clock position. Find the real temperature first before blaming the fans/cooling setup.

[ForcedFirebird]

Have you verified your actually temperature is high, and not just the gauge acting up? "3/4 on the gauge" might actually be normal when taking the temperature at the engine itself.

[Leonstt]

Update & question

I changed a few parts since I started this post.

I went back to fitting the fan clutch and still using the electric pusher fan. Not sure what the size was but it was the largest I can fit. And I installed the VDO temp gauge (I took the reading from the top rad hose). After driving the car for a while, I notice that my temp gauge fluctuates a bit. During superhot days and in stop and go traffic, my original temp gauge was hovering around 3/4 mark and the VDO was at around 95-98ish °C (203-208°F). But during highway runs and normal road with no traffic, the original temp gauge was sitting slightly below half and VDO was around 85-90°C (185-195°F).

My question is, is it normal that my engine temp fluctuates like it is now? It has never gone above 3/4 so far and it took usually around 20-30 min of driving to reach that temp. And yes my system is fully and properly bled