Cooling system struggles

[samthejam]

Newspaper? What's that? lol

dust off the playboys

[bigjae46]

dust off the playboys

Why would you ruin a playboy by sticking it in a fan?

[BTB]

Is consensus that OE is the best overall cooling package for street/track with A/C? Tired of having needle creep in hot Central Texas with A/C on. I have Bimmerworld C&R rad and Mishimoto electric fan, considering doing a refresh with all new OE (maybe aluminum expansion tank?). My heater hasn't been working recently so I may have an air bubble/leak somewhere, would like to get the car as close to bulletproof as possible. For what it's worth I've done a couple track days in fairly hot >90 F Texas weather and no issues at all, though no A/C running

[Dave092]

Is consensus that OE is the best overall cooling package for street/track with A/C? Tired of having needle creep in hot Central Texas with A/C on. I have Bimmerworld C&R rad and Mishimoto electric fan, considering doing a refresh with all new OE (maybe aluminum expansion tank?). My heater hasn't been working recently so I may have an air bubble/leak somewhere, would like to get the car as close to bulletproof as possible. For what it's worth I've done a couple track days in fairly hot >90 F Texas weather and no issues at all, though no A/C running

I do know that the overall consensus is that all OEM new cooling system components is the way to go for most use cases. What I don't know still is what the actual acceptable temperature range for coolant on these cars is. Considering the gauge will start to creep at 203F but many say it shouldn't creep I'm starting to think nobody really knows because 203F seems very very safe as far as I've always known.

[moproblems]

I do know that the overall consensus is that all OEM new cooling system components is the way to go for most use cases. What I don't know still is what the actual acceptable temperature range for coolant on these cars is. Considering the gauge will start to creep at 203F but many say it shouldn't creep I'm starting to think nobody really knows because 203F seems very very safe as far as I've always known.

Yeah my coolant temp on track was up towards the line between center and red and was extremely worried but then I realized that was barely 100c. Not really much of a worry. Still replacing everything anyways.

[dreamdrivedrift]

I have the same experience
Full OE setup: BMW radiator, OE water pump, 60/40 water/coolant + water wetter.

Multiple push laps shifting at redline at Laguna when weather is warm and it will be in the red, around 215F
I'll back off around there
Cooler weather it does OK
Thunderhill it does fine lap after lap

The problem with Mt Baldy is probably the altitude
I think really depends on air flow - don't think the E46 design flows air well enough

Possible solutions you can do:
Increase water/coolant ratio
Water wetter
Hood venting
Upgraded radiator: DO88, PWR. NOT CSF (that is 1000000% worse than OE)

[Mike RT4]

Another thing to check for is hydrocarbons in the coolant. S54s are known for doing headgaskets and this pressurises the coolant system and can give the symptoms you describe. Something that can then be eliminated very easily. If you have a failing head gasket, it doesn't matter how good your cooling system is, or what changes you make to it, it wil always overheat on WOT and cool back down quickly as soon as you get off the throttle.

Also the BMW gauge is just that (and a very rough "gauge" of the temps). I always monitor the temps on track via the OBD and iBus (displayed on my Avin 4). In the UK, it very rarely goes above 25°C, where I am seeing consistant high 80s/low 90°C (standard BMW set-up). HOWEVER, when on track, I remove the front number plate so that the front bumper has a completely unobstructed flow of air through it. I have always done this though, so not sure how beneficial it is, but it makes sense to not disrupt the flow to the radiator / oil cooler.

[prostcfc]

I was hitting the right-most dot this past weekend during afternoon HPDE sessions. Oil temps were left of the right-most dot. My phone said ambient temp was 85F though the car said 95F, so who knows. It was warmer than every HPDE I did last year. It would spike after the last straight and into a slow corner, and would slowly drop over the course of the lap until I hit the next straight; short shifting didn't change anything.

Car has 96k, and afaik has the same cooling system as when it rolled off the assembly line, so I think replacement is in order. Knowing that the right dot is still considered "normal", I wasn't too fussed about it, though I kept an eye on it, so lap times suffered.

[ramzM3]

I was hitting the right-most dot this past weekend during afternoon HPDE sessions. Oil temps were left of the right-most dot. My phone said ambient temp was 85F though the car said 95F, so who knows. It was warmer than every HPDE I did last year. It would spike after the last straight and into a slow corner, and would slowly drop over the course of the lap until I hit the next straight; short shifting didn't change anything.

Car has 96k, and afaik has the same cooling system as when it rolled off the assembly line, so I think replacement is in order. Knowing that the right dot is still considered "normal", I wasn't too fussed about it, though I kept an eye on it, so lap times suffered.

Knowing the right dot is considered "normal", is that a new thing? IDK, my car is a street driven car I've had for 16 yrs and it didn't used to go past center, except on occasion, just ever so slightly, on the hottest Florida days, but now, I'm having it go up to the right dot and a little more, in stop and go traffic on hot days more often than I can count on all my fingers and toes. I think that I either have some air in the system from when some cooling system parts were replaced and the system wasn't properly bled or some other component is failing and I just haven't found out which one yet. I've had the following components replaced over the past 5-6 yrs: fan clutch, fan blade, thermostat, water temp sensor, coolant expansion tank, water pipe O-ring, aux fan switch, lower radiator hose and coolant(a gallon at a time, when the lower radiator hose, coolant expansion tank, and coolant temp sensor were replaced).

[prostcfc]

Knowing the right dot is considered "normal", is that a new thing? IDK, my car is a street driven car I've had for 16 yrs and it didn't used to go past center, except on occasion, just ever so slightly, on the hottest Florida days, but now, I'm having it go up to the right dot and a little more, in stop and go traffic on hot days more often than I can count on all my fingers and toes. I think that I either have some air in the system from when some cooling system parts were replaced and the system wasn't properly bled or some other component is failing and I just haven't found out which one yet. I've had the following components replaced over the past 5-6 yrs: fan clutch, fan blade, thermostat, water temp sensor, coolant expansion tank, water pipe O-ring, aux fan switch, lower radiator hose and coolant(a gallon at a time, when the lower radiator hose, coolant expansion tank, and coolant temp sensor were replaced).

The manual says it's "normal" though I've only had it on hot track days. Normal driving I'm closer to the left dot and idling the center. I'm in the Chicago area so it's not oppressively hot here constantly.