M6x e30 - More cooling power?

[E30335i]

M6x e30 - More cooling power?

I’m sure it will take some time figuring out, there’s a guy on Bimmerforums who had clutch fan and bigger electric fans or 2 of them? I gotta look in his e38 that he tracks, anyways,
After a straightaway during braking his car has a heat spike but after he accelerate it goes down. Anyways, time to make a fan shroud?

You should add a temp gauge so you have an accurate reading and double check your temperatures with a infrared from harbor freight and make sure nothing is clogged, fully opening thermostat, etc., just as a double check if you haven’t done that.

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[varg]

Hmm. Based on my temp readout in tunerstudio, 180f (82c) is the second mark on my E30's temp gauge.

[noid]

The temp reading high is a mixture of a couple things.

1. The E30 has an unbuffered temp gauge, meaning it will go up and down relative to the specific ohms it sees.

Most M62 equipped cars had buffered temp gauges which showed the needle at dead middle between a range of temperatures:

http://www.e38.org/e32/BMW_pdfs/INST_info.pdf

This range of temperatures could go up to 95c and still be considered normal operating temp. On an E30 cluster this would show as a few ticks past middle.

2. The E30 gauge is calibrated to show 80c as middle, the M60/M62 ran a few different thermostats, a 95c thermostat (e34) and 85c thermostat (E39/E38).

As Jean pointed out, these engines are meant to run hotter. Using a gauge calibrated for a cooler engine will always show the engine as running hot.

BMW started using 95c thermostats on the Nikasil blocks as it seemed to slow some of the damage that was being caused by sulphur in fuels.

[alistairolsen]

Excellent work Jean! Very thorough

[Jean]

I have similar issues, I watch the temp bounce between 220-235 on the obd1 m62, running m60 wp & thermo/z3m rad and a spal 16" pusher w/gasket against rad. No ac/heater though, but i've run a block test and compression a few times to make sure it isn't a HG issue since my donor was 150k.

I still haven't determined if the temp gauge is faulty or what but my readings on my vent says its 223-225 but cluster will show 3/4 at operating. Oil temp will sit about 205-220 roughly around 40psi if memory serves correct. Haven't had the chance to auto-x it yet but i've had some fun and beat it around. I've been on the fence about chopping some holes in the hood and ducting the radiator since I've noticed pulling the hood gasket made about a 5-10 degree difference when I was looking at 235.

My neighbor who just sold his miata for an e36 m3 had a few vents on his hood cut out so I stopped him one day to gab. Told me he's looking at around 15-20 degree difference with the vents since he installed them. Granted we're talking a NA stock 4 cyl but thats a pretty noticeable difference. I believe he was running a dual 8" puller set up wired to in cab switch.

On the other hand, my e38 m62 runs around 225-235 in traffic/under load and have read that the m62s run higher temp for emissions. I've yet to meet someone local with an m60 swap to hash out the details between our two cars but would like to figure out the variables between them.

It's most likely not the gauge or the cluster, the e30 cluster temp reads the 1/2 mark when it sees about 46 ohms and get's to 3/4 mark when it sees around 33 ohms from the sender. I read this by connecting a variable potentiometer in place of the sender and basically ran the pot from cold to green and recorded ohm readings vs gauge needle position.

What I then did was placed another brand new brown e30 sender in a pot of hot water an measured it's temperature using an infrared thermometer and recorded the ohms vs. temperatures .

What I found that the stock e30 temp gauge when using e30 sender will read past 1/2 mark for the operating temperature of the m6x as these engines run hotter than e30 engines.... obd2 engines run hotter stock for emissions.

When my e30 cluster gauge was showing at or almost 3/4 mark I used my infrared thermometer to check the temperatures at the water pump, the coolant pipes, top of the radiator and rear coolant pipes and have not seen temperatures higher than 210f.

e30 cluster will read on the high side for 210f, but the stock e32/e34 clusters with their matching temp senders for these engines will not read as high.

Just sharing what I've learned by doing some measurements and readings. I've since purchased a stand alone vdo vision temp gauge and sender that I've yet to install for peace of mind (and same for engine oil temp).

[dasmanschaft012]

picture of shrouding? getting that airflow right is super important

[Denny]

Looks like I was not the only one with the same problem took me a month of back and forth datalogging with my ms2 setup to find out the best adder was to shroud the rad support so ALL air has to go trew the rad..made a 15 degree difference. Im constantly at 97 degrees celcius stopped and around 90 when moving.

[robiniscool]

did you ever figure it out? I have a obd1 m62, without ac its about 197-200F but when ac is on it just keeps creeping up. I usually end up shutting off A/c at around 220-225 cause it gets me nervous. I'm actually running a 85c thermostat and two very slim 10" spal puller fans on a behr z3m radiator along with the oem condenser fan. With all this I'm still having problems with cooling but only if I decide to use A/c

[DIIRTY-30]

I have similar issues, I watch the temp bounce between 220-235 on the obd1 m62, running m60 wp & thermo/z3m rad and a spal 16" pusher w/gasket against rad. No ac/heater though, but i've run a block test and compression a few times to make sure it isn't a HG issue since my donor was 150k.

I still haven't determined if the temp gauge is faulty or what but my readings on my vent says its 223-225 but cluster will show 3/4 at operating. Oil temp will sit about 205-220 roughly around 40psi if memory serves correct. Haven't had the chance to auto-x it yet but i've had some fun and beat it around. I've been on the fence about chopping some holes in the hood and ducting the radiator since I've noticed pulling the hood gasket made about a 5-10 degree difference when I was looking at 235.

My neighbor who just sold his miata for an e36 m3 had a few vents on his hood cut out so I stopped him one day to gab. Told me he's looking at around 15-20 degree difference with the vents since he installed them. Granted we're talking a NA stock 4 cyl but thats a pretty noticeable difference. I believe he was running a dual 8" puller set up wired to in cab switch.

On the other hand, my e38 m62 runs around 225-235 in traffic/under load and have read that the m62s run higher temp for emissions. I've yet to meet someone local with an m60 swap to hash out the details between our two cars but would like to figure out the variables between them.

[varg]

It's probably all going to come down to the fact that you need a bigger/more powerful pusher fan. Which spal did you have? Some ducting and sealing between the condenser and the radiator is necessary too. It's likely there's a decent size gap somewhere which is reducing the effectiveness of the pusher setup.

[strang3majik]

I bet the spal fan wasn't set up properly.
Seal fan to rad (they make a neat gasket for this)
Seal rad to core support (aka ducting!!! super important)
Pay attention to where air wants to vacate

Hows the heater work? Nice and hot? When was the last time you bled the car?
What do your heater core hoses look like? Do you know your oil temps on track?

I had the fan gasket...fan was tight against the condenser. The stock aux fan still works better and it's mounted in the stock location.

Heater works very well...like too much. Last time I bled it was probably 6 months ago when I installed a brand new reservoir.

Heater core hoses are new and as good as they can be with the m62..

No idea on oil temps.

My fan is set to full time high speed. Temps range from 200 to 210 in normal operation. Near 230/235 when in the scenarios I mentioned prior.

High speed driving it's fine...normal driving it's fine.

Just low speed hard throttle and idling with the ac on.

I understand the real issue is insufficient airflow, but aside from moving the engine back into the firewall, there's no room for a puller fan.

When idling with the fan on, ac off...it has the power to bring it back to normal opersting temp.

[E30335i]

I bet the spal fan wasn't set up properly.

Seal fan to rad (they make a neat gasket for this)

Seal rad to core support (aka ducting!!! super important)

Pay attention to where air wants to vacate



Hows the heater work? Nice and hot? When was the last time you bled the car?

What do your heater core hoses look like? Do you know your oil temps on track?

On top of that maybe your cooling is not regulated or consistent? Maybe high speed should come earlier? But ducting & fan shroud is important if in your situation as well


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[dasmanschaft012]

Don't think I'm going to get much better than a z3m 3 core rad...and idk the stock aux fan CFM, but it cools better than my 2200CFM SPAL did.

I bet the spal fan wasn't set up properly.
Seal fan to rad (they make a neat gasket for this)
Seal rad to core support (aka ducting!!! super important)
Pay attention to where air wants to vacate

Hows the heater work? Nice and hot? When was the last time you bled the car?
What do your heater core hoses look like? Do you know your oil temps on track?

[E30335i]

My preference would be to max out my cooking options before I make a decision


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[strang3majik]

Sorry for the delayed response...my email updates aren't working. :/

If it was me, I would start with getting a fan with a high CFM. If that didn't work, I would look into getting a bigger radiator.

Don't think I'm going to get much better than a z3m 3 core rad...and idk the stock aux fan CFM, but it cools better than my 2200CFM SPAL did.

I'm running a Mishimoto Z3M radiator, with a Spal 16" pusher. I'm running a M60B40, OBD1 obviously, Stock M60 thermostat, stock M60 Water pump, and I have the heater hooked up. I don't have AC. I have my Spal fan on a switch in the cab, because when I wired everything up, I couldn't get a strait answer on what temp the fan should kick on at.

Mine stays pretty rock solid at half 80% of the time. The other 20% is usually in heavy traffic, or lots of time in 2nd gear. If I catch the temp going up before it gets half way between the half and 3/4 mark, usually the Pusher is enough to bring it back down. IF that doesn't work, then all I gotta do is kick the heater on for a bit. Once I get back down to half. I usually leave the Pusher on, until I get out of traffic.

I have exeprenced what you're described before, and my issue was a air bubble in the system still. Once I worked that out, everything was good.

Mine will never overheat at idle/in traffic if the AC is off, but if the AC is on it will. The hard driving/autox running warm is what bothers me. Does the same with mountain driving, but typically decel down the mountain cools it right back down. I've never had it go past 3/4 but it has touched it before. My fan is wired to be on with the key...so it is always on. Usually runs at 3/8-1/2 on the temp gauge...1/2 is about 210°F

Is the radiator getting enough airflow? You may want to look at creating/installing rad shrouds to direct as much clean airflow thru the rad face as possible.

I’ve seen a few race cars were this was done (trial and error) with good results. ( I love laser temp guns. So easy to gather good data). Is your temp gauge accurate?

Always hard when they sit in pregrid but as soon as they moved, needle dropped. Should be the same with a street car.

Other thoughts in no order- my speciality...
Is your water pump belt tight enough? Did you test your thermo? Is your WP impeller in good shape? Have you flushed the block /rad? Rad pressure is good? System well bled? I see that many E36 guys are going with hood vents. . . . Which I find totally cool. No pun intended.
Good Luck cause it looks to be a bloody long hot summer....

I'm honestly not sure how much shrouding could be done. I have the stock aux fan, stock AC condenser, then the radiator. The water pump pulley is about 1/2" from the radiator at the back...enough that I have to pull the radiator to change the belt. :/

When I mention temps I am going off of the gauge confirmed with a scanner reading off of the CTS...which with the m6x swap is a separate sensor. Both seem to agree with each other.

Water pump belt and tensioner are new and very tight. Water pump is new as well as the thermostat. Rad was new and the block was flushed by the machinist...when I say new, everything was replaced when I did the swap 3 years ago...haha. Its had this issue since then, just noticing it more often since I added AC...lol System is well bled to my knowledge. Heat works and is hot as hell...never see quick temp fluctuations. Could flush and refill, I suppose. I'm even running Water Wetter in it. :/

Hood vents would be good if I can find some that are subtle...I want to make a tray for them though so I can drive in the rain. Haha.

But yes...thank you. Our summer here started 2 months ago...haha. 95°F with 100% humidity is not uncommon. Even at night it will "cool off" to 85°F, but still at 100% humidity.

If you do a hood vent, it’s a minimum 20 degree difference.


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So do you recommend hood vents? 20 degree difference minimum is pretty substantial.