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

[BigRussia]

Good to see you got it resolved. I had a similar experience where I replaced a CSF rad with OE and now my cooling system is rock solid... Even in 100+ heat sitting in traffic.

Thanks! But not quite yet haha, I should remove the 'Resolved!' from the thread title, since its misleading at this point 😅 Even though the switch from the bunk CSF radiator to the new OE BMW unit was a significant 'discovery'. Just hoping its not all for moot and ends up being an engine internal related issue :/

Not having the factory radiator shrouding and ducting will have a major impact on your cooling. A lot of times, you have to go beyond the factory and actually take the front end apart to seal up all of the gaps to improve the cooling function of the radiators (oil and water). All of that air not going to the right place adds up, even if it looks like an insignificant amount.

You mean the proper front ducting yes? If so yup agreed, those gaps between the rad and headlights are concerning me. If i can get a reference from a E46 M3 that has not had any incidents to poke my nose into I'd know for sure! Or if someone on here can be a real chap and try shining a light there same as me and see if have the same amount of gaps

I would think that the factory rad ducting in the engine bay only really has an impact at lower speed where the puller fan is responsible for most of the airflow over the rad.

On track the puller fan rad ducting shouldn’t have much impact on the airflow over the rad.

I think a product like the buildjournal part would have a higher impact on track cooling than the factory fan shroud around the puller fan.

Yup agree as well, thats why I dropped bothering fitting the mishimoto e-fan into a stock fan shroud. That was going to my next project till I realized that may not be the cause in my case (being high speed high load on track where there's plenty of airflow already and always moving).

EDIT: Also forgot to mention car has a TTFS Custom Dyno tune by the elusive Frank Smith himself lol. I initially thought cooling issues arose after I got it. But nope was happening on previous tune as well. Though a retune by Hassan at HTE is also on my considerations.

[usdmej]

it would be worthwhile to let CSF know their radiator let you down. you rarely hear bad stories about them so they might do something productive with the info.

[Obioban]

I suspect he meant the duct in front of the rad.

[eacmen]

Not having the factory radiator shrouding and ducting will have a major impact on your cooling. A lot of times, you have to go beyond the factory and actually take the front end apart to seal up all of the gaps to improve the cooling function of the radiators (oil and water). All of that air not going to the right place adds up, even if it looks like an insignificant amount.

I would think that the factory rad ducting in the engine bay only really has an impact at lower speed where the puller fan is responsible for most of the airflow over the rad.

On track the puller fan rad ducting shouldn’t have much impact on the airflow over the rad.

I think a product like the buildjournal part would have a higher impact on track cooling than the factory fan shroud around the puller fan.

[t44tq]

Not having the factory radiator shrouding and ducting will have a major impact on your cooling. A lot of times, you have to go beyond the factory and actually take the front end apart to seal up all of the gaps to improve the cooling function of the radiators (oil and water). All of that air not going to the right place adds up, even if it looks like an insignificant amount.

[robgill]

Good to see you got it resolved. I had a similar experience where I replaced a CSF rad with OE and now my cooling system is rock solid... Even in 100+ heat sitting in traffic.

[BigRussia]

So what next? I started thinking of everything else, including adding a real shroud for the radiator w the e-fan, the ducting and airflow in the front of the car, even considering running thinner oil like 50w, and lastly maybe it all being for naught and it's really an issue with my tired high mileage engine's internals causing extra friction and the extra heat (but then wouldn't the oil temps also be getting too hot?) So I was initially set on mounting the mishimoto e-fan into a factory plastic fan shroud, but further reading and research led me to realize that's more for idling and stop n go traffic, which my car has 0 issue with, and can even be a restriction at higher track speeds. I can dog the car on the streets np in sunny 90F humid summer day and water temps will never rise past 200F. So a radiator shroud was ruled out, so now my attention is on making sure there's no gaps in the car's front ducting and making sure ALL the air flows over the coolers, and not around!

So the car did have a front end accident reported from a few owners back, and since my ownership I discovered few loose parts of the bumper and other brackets that I've since addressed and fixed w new parts over the years. But it also lends to being likely the proper ducts and seals for the front airflow are not there or cat least compromised! So lets start checking:

First check, the front air duct. Yeah the bottom part of the plastic is dipping down a little bit but looks like the CSF oil cooler is still lower than the flaps, maybe it dips down at higher speeds who knows? And there is one piece by the upper rightside kidney part thats' sheared but again doubtful this is a major issue.

How a fresh new Front Air Duct looks above


How my Front Air Duct currently sits, note the droop of the bottom, bowing down a bit. Significant to contribute to the overall cooling dilemma?

The shear at the upper right side kidney area, insignificant most likely

I began to consider the Buildjournal Radiator Duct as a replacement/upgrade, does anyone have experience with this piece? Seems to price out to the same as buying a new factory front air duct + lower grill (my car was missing that too of course, #23). I figure it doesn't hurt to try it but seems it'll more beneficial to oil cooling than water, and again my oil temps are under control (never touched 250F surprisingly even with the water temps soaring).

https://thebuildjournal.com/shop/bmw...r-duct-e46-m3/

Next was to check around the radiator itself, looking on realoem i see the side brackets and gaskets highlighted below. I am planning to take off the whole front end this weekend to really get in there, but right now I can shine a light through the sides of the radiator between each headlight housing (pictured below)... is that normal factory setup or am I truly missing these bracket/gaskets or something? Can anyone else confirm how the areas on the side of the radiator look on their own car from factory? I'm sure #6 and #7 are there as they seem to be brackets that hold up the radiator, but i cant visually confirm if those gaskets #8 and #9 are there, at least not without yet taking things apart.


Drivers side radiator 'gap' with lamp shining behind


Passenger side radiator 'gap' with lamp shining behind (normal or missing pieces due to front end accident from past?)

If you made it this far reading these posts, thanks in advance!

[BigRussia]

Hey all, its ya boi back again! LOL, I might have put the 'RESOLVED' tag in the title too soon, as my quest for track cooling continues (unfortunately). So bumping this thread up again and at this point basically becoming a build log/journal. Figure I at least make it an entertaining read for future folks who might come across it and have similar track water temp cooling issues. So strap in for a long winded read and hopefully a happy ending, or witnessing my descent into madness (looking at the size of these walls of text i might already be on my way).

So, last time on 'BigRussia's E46 M3 Track Cooling Saga': After a complete cooling system overhaul, it looked like the main culprit was a faulty (i.e shit) CSF rad causing most of the cooling issues. Replacing w/ a brand new genuine OE BMW radiator seemed to be the biggest impact and track water temps improved, no longer soaring past the 3/4 dot on the factory water gauge. I did a very cold (by SFL standard) trackday at Homestead Miami Speedway and temps stay rock solid, around the 200's IIRC, and even set my new PB so was hustling the car.

A quick summary of my current setup:

-Refreshed cooling system: OE BMW Radiator and Waterpump, OEM thermostat, temp sensor, and new hoses, 90/10 distilled water mix w/ 1 bottle BMW coolant and 1 bottle RL water wetter. Also new OEM A/C Condenser as original was so banged up it was causing airflow problems.

-Car: Dual purpose street/track, 183k miles original drivetrain, has A/C and front factory Aux fan (not giving it up in SFL, again its still a street car), mishimoto e-fan kit (no real shrouding just the mounting bracket it comes with, none of the factory plastic fan shrouds or side ducts were retained by previous owner who installed the kit), CSF oil cooler (seems to be doing its job fine, even though I considered overhauling my factory unit to get back 8lbs the CSF oc added and utilize the duct/shroud the oe oc sits in and directs airflow behind it downward, noticed the D088 unit has a similar downward duct), lastly car has a Custom TTFS Dyno tune done by the elusive Frank Smith himself lol. I initially thought cooling issues arose after I got it, but nope was happening on previous tune as well. Though a retune by Hassan at HTE is also on my considerations.

To reiterate, the car is rock solid cool on the streets even with the e-fan kick-on set above the oem thermostat opening (i think it's around 80-85c).

Since then, as a further step I replaced the banged up and cracked plastic under tray belly pan with a new unit, in hopes that maybe that will help with airflow behind the radiator since I read about potential pressure differences problems w/ a cracked pan letting turbulent air flow into the engine bay. Who knows, I'm not an engineer and havent truly studied aero and thermodynamics.


Old vs new belly pan

Well I didnt really get to try this out to see any improvement as my next track stint was a maiden voyage to the world famous Sebring International Raceway, where I only got 2 sessions in before day was cut short due to lightning. I didnt really get to push the car hard since was my first time on that track, but again I saw water temps go past 200F and approach 210+ when pushing

to be continued...

[Casa de Mesa]

Casa: "Hey Google. WTF is an air comb"

[jet_dogg]

I was simply advocating the right tool for the job, no more no less. Sure others can get the job done to varying degrees, don't read too much into it as nothing was directed toward you.

So in closing, the moral of the story is if you have a csf radiator and you are running into high temp situations then you most likely need to go back to an oe radiator.

Hopefully those issues don't lend themselves to a head gasket situation down the road like we've seen.

[mrgizmo04]

I do a lot of house maintenance shit myself but when I need stuff built I'm fortunate to have an army of tradesmen at my disposal; guys who build stadiums, airports, high rises and shit or a proper hvac system, ductwork, electrical or high end cabinetry/fine finish carpentry work which is far beyond my scope of talent. With that being said the only reason I like doing some little car maintenance bullshit is because I get to use my nice tools but I don't consider that stuff diy.

Aside that, I always look for the most efficient way to perform a task so I personally would definitely get what I recommended instead of fussing around with a garden hose but that's just me. Your mileage clearly varies.

Maybe I misunderstood your response to my post as you assuming I had air to make the job easier. So I was just sharing how i have done it on the topic at hand. I've also used vacuum cleaner with good results. Tracking the car gets a lot of dirt especially on the off excursions, into the fins. Most of the time when cars are overheating doesnt mean a new water pump is needed, a simple clean of fins to restore the radiator efficiency to do its radiator thing is all that's needed. No harm if I misunderstood.

I'm not here to measure who has better tools or who has a mechanic work on their car. I'm here just to provide information and help out.

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[jet_dogg]

I'd consider myself a pretty hardcore diy-er (cars, house, etc) but I don't have air. Garden hose works just fine for this purpose too. Oil cooler - I started leveraging fcp, just too much track fun and offs with that thing sitting in clear line of fire, that blasting it out and cleaning at some point stops working well, given the small surface area.

Sent from my SM-G950U using Tapatalk

I do a lot of house maintenance shit myself but when I need stuff built I'm fortunate to have an army of tradesmen at my disposal; guys who build stadiums, airports, high rises and shit or a proper hvac system, ductwork, electrical or high end cabinetry/fine finish carpentry work which is far beyond my scope of talent. With that being said the only reason I like doing some little car maintenance bullshit is because I get to use my nice tools but I don't consider that stuff diy.

Aside that, I always look for the most efficient way to perform a task so I personally would definitely get what I recommended instead of fussing around with a garden hose but that's just me. Your mileage clearly varies.

[mrgizmo04]

If I was a diy'er I'd definitely have air in the garage along with an air comb for this exact purpose.

I'd consider myself a pretty hardcore diy-er (cars, house, etc) but I don't have air. Garden hose works just fine for this purpose too. Oil cooler - I started leveraging fcp, just too much track fun and offs with that thing sitting in clear line of fire, that blasting it out and cleaning at some point stops working well, given the small surface area.

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[Obioban]

I'd probably be a diy'er if I lived in a random state.

Luckily I'm friends with guys who have been working on m cars for almost two decades so I leave it to the professionals.

I meant in all things— not just cars.

[jet_dogg]

I'd probably be a diy'er if I lived in a random state.

Luckily I'm friends with guys who have been working on m cars for almost two decades so I leave it to the professionals.