Help diagnosing high water temps at track - Resolved? (not really!)

[Obioban]

I'd try the tune, first, as it's a free/easy check, but the CSF rad is certainly a prime suspect.

Just got back from a weekend of 95 degree+ sessions, coolant temps never went past vertical. OE BMW rad.

[jet_dogg]

Your problem is most likely the csf rad.

[GolanM3]

Well, disappointing results nonetheless. Replaced both pulleys with no improvement, although it's only when pushed hard, with several pulls back to back to 8k RPM, the temp will go over 205 degree and move the needle pass the half point.
I'm running out of ideas, next I'll have to check the tune. Planning to take it to the dyno to get air/fuel ratio and see if that could be culprit, although I don't have high hopes. Any ideas/suggestions?

[Obioban]

What do you guys think? the Evosport pully is almost 1'' larger, that would make the WP spin slower, most noticeable at high RPM which I think this is why it's only overheating at the track.

It’s certainly not improving your cooling 😜

[GolanM3]

What do you guys think? the Evosport pully is almost 1'' larger, that would make the WP spin slower, most noticeable at high RPM which I think this is why it's only overheating at the track.

[BigRussia]

I'd say it probably depends what you're under driving. If you're under driving the water pump, that could be related. If you're under driving the power steering pump, less likely.

My car came with the Active Autowerke pulleys so I didnt research them before purchasing like I do all my own modifications. They're discontinued so was hard to find info on them as they're not on AA's site anymore, but found an old post on E46Fanatics from one of their sales guys and seems it underdrives all 3 accessories: wp, ps, and alternator. Interesting excerpt from his sale post:
'Does not cause overheating similar to smaller pulley designs
R&D tested in Miami to ensure no overheating issues'

Last line sticks out to me, as I kind want it to make me feel better. I'm in Miami as well and know AA is too, been to their shop (they even did the RB job on my E92M) but naturally I'd take anything a sale person says about their own products with a grain of salt lol. Either way I dont truly think the pulleys are my issue.. at least I hope under-driving the wp isnt.

I have the exact same behavior. I did 5 events earlier this year and the temps were never an issue. The last event I attended I spent most of the time worried that around lap 10 the temp gauge would creep up.

I am trying to sign up for an event in a couple weeks. I was going to swap out my pullys before then.

Interested to see the results.

Interesting, yeah I was sure I wouldn't see anyone else with my exact same pattern that led up to my issue lol, but glad I'm not the only one. Misery loves company I guess, but at least means we can all really help sort this out. Definitely keep us updated!

I was supposed to take my car to the indy this week to start diagnosing the cooling system and refresh but his main tech was out sick, so really trying to get the car to the shop next week and dig into this. I too am planning to do a track day as soon as I get the car back to test out if the issue gone or not, hopefully by mid September, if not early October.

[Fresh1179]

Hmm so all 3 of us both have underdrive 'power' pulleys? There might be something there... my car came with the AA pulleys. But since my car came with them I don't think they're the cause of my issue, since my issue occurred my last 2-3 track days and I've tracked the car more than a handful of times before and didnt have the issue till recently.

I have the exact same behavior. I did 5 events earlier this year and the temps were never an issue. The last event I attended I spent most of the time worried that around lap 10 the temp gauge would creep up.

I am trying to sign up for an event in a couple weeks. I was going to swap out my pullys before then.

Interested to see the results.


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[Obioban]

Hmm so all 3 of us both have underdrive 'power' pulleys? There might be something there... my car came with the AA pulleys. But since my car came with them I don't think they're the cause of my issue, since my issue occurred my last 2-3 track days and I've tracked the car more than a handful of times before and didnt have the issue till recently.

I'd say it probably depends what you're under driving. If you're under driving the water pump, that could be related. If you're under driving the power steering pump, less likely.

[bimmer]

Really does seem like CSF is not really an upgrade, I've had that in my mind as one of the possible causes as I've been trying to rule out everything causing this issue. I heard earlier version had issues w/ flow and clogging? Mine must be from 2016 at least. I'm considering adding a new OEM rad to my cooling system refresh job, but curious is the CSF aluminum rad even any lighter than the OEM rad? My car came with the CSF so didnt have the OEM handy to notice any weight difference.

I can tell you from when I had them side by side that the OEM is definitely lighter than CSF. And according to FedEx shipping facts, the OEM was ~10lbs and CSF ~15lbs. That's obviously not an exact science, but corroborates my "by feel" conclusion.

If you are doing the cooling refresh anyways, I'd just swap in the OEM. Apparently you won't lose any cooling performance and you'll save some weight as well.

[BigRussia]

Bingo! I really think this is the culprit. From what I read online and talking to a friend with the similar setup who drives the car hard, but still has the STOCK pulley, I have high confidence that fix the problem (please god, please!). I have ordered a stock oem pulley that should arrive over the weekend. I'll install it as soon as I can and report back. Fingers crossed!

btw... BigRussia, what WP pulley do you have on your car??

Hmm so all 3 of us both have underdrive 'power' pulleys? There might be something there... my car came with the AA pulleys. But since my car came with them I don't think they're the cause of my issue, since my issue occurred my last 2-3 track days and I've tracked the car more than a handful of times before and didnt have the issue till recently.

[GolanM3]

I’ll post a puzzle to this crowd:

New OE Water Pump
New Hoses
New Coolant Expansion Tank and Overflow Line
New RE Street* Under-drive Pullys
New Zionsville Race Radiator with Spal Fan
New 60/40 Coolant (Water/OE Coolant)
Vacuum Bled
New T-Stat
New O-Rings

I’m considering starting with the removal of the underdrive pullys. Am I going to need to switch back to a clutch fan….Car is overheating to the second dot later in sessions, approximately 20 minutes in. Head gasket…..

Edit: I’ll look at the Datalogger for more accurate temps


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Bingo! I really think this is the culprit. From what I read online and talking to a friend with the similar setup who drives the car hard, but still has the STOCK pulley, I have high confidence that fix the problem (please god, please!). I have ordered a stock oem pulley that should arrive over the weekend. I'll install it as soon as I can and report back. Fingers crossed!

btw... BigRussia, what WP pulley do you have on your car??

[yhp2009]

I’ll post a puzzle to this crowd:

New OE Water Pump
New Hoses
New Coolant Expansion Tank and Overflow Line
New RE Street* Under-drive Pullys
New Zionsville Race Radiator with Spal Fan
New 60/40 Coolant (Water/OE Coolant)
Vacuum Bled
New T-Stat
New O-Rings

I’m considering starting with the removal of the underdrive pullys. Am I going to need to switch back to a clutch fan….Car is overheating to the second dot later in sessions, approximately 20 minutes in. Head gasket…..

Edit: I’ll look at the Datalogger for more accurate temps


Sent from my iPhone using Tapatalk

I think the recurring theme is to use OE BMW Radiator as all aftermarkets cause problems

[Fresh1179]

I’ll post a puzzle to this crowd:

New OE Water Pump
New Hoses
New Coolant Expansion Tank and Overflow Line
New RE Street* Under-drive Pullys
New Zionsville Race Radiator with Spal Fan
New 60/40 Coolant (Water/OE Coolant)
Vacuum Bled
New T-Stat
New O-Rings

I’m considering starting with the removal of the underdrive pullys. Am I going to need to switch back to a clutch fan….Car is overheating to the second dot later in sessions, approximately 20 minutes in. Head gasket…..

Edit: I’ll look at the Datalogger for more accurate temps


Sent from my iPhone using Tapatalk

[Obioban]

Man that's crazy, I still havent gotten around to resolving this issue but was planning on finally taking my car to my indy shop next week for a cooling system refresh (new thermostat, wp, thermo sensor) hoping that would resolve it, since im sure its a faulty thermostat. I recently got a OBD P0128 code, which is coolant taking too long to warm up to normal operating temp, so figured it must be the thermo since I've had the car too hot and now says its taking too long to warm up lol.

But that's discouraging that the cooling system refresh didnt resolve the issue in your case Did you install the CSF radiator after the issue happened, or already had it on the car when the issue started happening?

I'm really considering a retune from Frank as well, just hoping my indy who did the tune with him can get ahold of him while my car is there for the cooling system refresh.



Really does seem like CSF is not really an upgrade, I've had that in my mind as one of the possible causes as I've been trying to rule out everything causing this issue. I heard earlier version had issues w/ flow and clogging? Mine must be from 2016 at least. I'm considering adding a new OEM rad to my cooling system refresh job, but curious is the CSF aluminum rad even any lighter than the OEM rad? My car came with the CSF so didnt have the OEM handy to notice any weight difference.

If you're tracking the car, you should really get off the TTFS tune ASAP. Multiple engine failures from their tunes on track, and it might fix your overheating issue as a side perk.

[BigRussia]

Hi everyone, I'm so glad I found this post. I have a 2003 M3 that I use for mostly track driving.
I have the same exact symptoms as was BigRussia describing. The car never overheat in traffic or any other condition, however at the track, only after a few laps and it goes past the half point.
So far I upgraded both radiator and oil cooler to CSF, replaced WP, thermostat and fan clutch. Pretty much every component in the cooling system, and still things have not gotten any better. I also thought I had head gasket issue, but my mechanic checked and confirmed no issues there.
Now what's interesting, is that I also have the TTFS tune (after install of euro headers). In addition, last night I used the OBD port to check coolant temps, and I see that temp gauge goes beyond the half point at around 205 degree, is that considered over heating? is there any buffering in the stock temp gauge that possibly the TTFS tune removed?
I hope someone can help figure this out..

Man that's crazy, I still havent gotten around to resolving this issue but was planning on finally taking my car to my indy shop next week for a cooling system refresh (new thermostat, wp, temp sensor) hoping that would resolve it, since im sure its a faulty thermostat. I recently got a OBD P0128 code, which is coolant taking too long to warm up to normal operating temp, so figured it must be the thermo since I've had the car too hot and now says its taking too long to warm up lol.

But that's discouraging that the cooling system refresh didnt resolve the issue in your case Did you install the CSF radiator after the issue happened, or already had it on the car when the issue started happening?

I'm really considering a retune from Frank (TTFS) as well, just hoping my indy who did the tune with him can get ahold of him while my car is there for the cooling system refresh.

For what it's worth, I just wasted the better part of two months chasing issues with my CSF radiator and high coolant temps on track. I swapped back to a brand new BMW OEM radiator and it instantly solved the issue.

https://nam3forum.com/forums/forum/m...e-street-track

Really does seem like CSF is not really an upgrade, I've had that in my mind as one of the possible causes as I've been trying to rule out everything causing this issue. I heard earlier version had issues w/ flow and clogging? Mine must be from 2016 at least. I'm considering adding a new OEM rad to my cooling system refresh job, but curious is the CSF aluminum rad even any lighter than the OEM rad? My car came with the CSF so didnt have the OEM handy to notice any weight difference.