Overheating e36 M3

[ethancoast]

so when i bought my 36 m3 the owner before me said he replaced the cooling system on the car, after a week of owning it the little check coolant message popped when i pushed the CHECK button, i didn't think much of it and fast forward like 3 months of owning it i was leaving my friends bank and i scraped and hit the front of my car damaging my auxiliary fan i was heading up my street a whiles away to a smith's and when i stoped moving my temperature went up and when i parked the temperature gauge was in the red. so after 3 days of driving with it i discovered that it would only overheat when i was at a stop, driving anywhere else the temp would go down and it would be "fine". 2 weeks ago i was at a stop on a hot New Mexican day and my car overheating way to much and the radiator hose popped off and all my coolant dripped out. my radiator is messed up and well my auxiliary fan doesn't come on at all anymore. should i replace those 2 things with thermostat and coolant change? or fix the entire cooling system, i know the cooling systems aren't the best on the car but the owner did claim he replaced it, the guy before me definitely took car of the car, plenty of receipts which i will be going through, and the car hasn't skipped a beat for me. i'm at a point of saving right now cause i know it will be around 600-700 to redo the system but i know my car will be better after.

[shogun]

Moved to E36 M3 forum

[RobertDenali]

You might be better off replacing all the parts with genuine bmw. You really don't know what parts are genuine / new unless the PO provided receipts.

Since you are already thinking of replacing the more expensive parts I would also consider the rest of the coolant system just to be safe.

[XnWarden]

No need to use genuine bmw parts. Fcp euro has very high quality oem parts at a fraction of the "genuine" price tag. Redo the entire system. It will be about $400.

The plastic endtanks on these radiators are very prone to breaking as you have just found out.

Sent from my VS987 using Tapatalk

[TostitoBandito]

The OEM radiator and many of the assorted accessories (like expansion tank) are made by Behr. Mahle and Febi are OEM's for other miscellaneous parts like thermostat/housing. Rein hoses are fine. Graf or Meyle for the water pump, or spring for the Stewart pump.

But yeah, no need to buy "genuine BMW" when the identical OEM parts are available for cheaper as I mentioned above. Sometimes you don't have a choice and have to buy the expensive BMW part, but most of the time you do. A little research and you'll quickly learn all the real European OEM's, and also all the cheap garbage "OEM's". Just go on FCPEuro or Pelican and go to town.

[SamGrant951]

Well if the sensor starts reading check coolant the coolant is probably going somewhere (ie being burned in the motor - head gasket leak), pushed/pressurized below the sensor or leaking externally via a hose or one of the parts mentioned above. Id replace everything and monitor the situation but you may be pulling the head off in the future as well - thats a buffered coolant gauge and when it goes towards the red its often too late, hoping its just needs a fan and a few parts.

[gdavid]

If your temperature gauge hit the red multiple times, it is likely the head was damaged. It is also likely that the previous owner overheated the car before you got it and that's what prompted him to replace the cooling system in the first place. I would recommend pulling the head and verifying that it is still good before replacing the entire cooling system again. Replacing the head gasket is a lot of work but you would be extremely frustrated to spend a few hundred and end up right back in the same place.

[blckstrm]

so when i bought my 36 m3 the owner before me said he replaced the cooling system on the car, after a week of owning it the little check coolant message popped when i pushed the CHECK button, i didn't think much of it and fast forward like 3 months of owning it i was leaving my friends bank and i scraped and hit the front of my car damaging my auxiliary fan i was heading up my street a whiles away to a smith's and when i stoped moving my temperature went up and when i parked the temperature gauge was in the red. so after 3 days of driving with it i discovered that it would only overheat when i was at a stop, driving anywhere else the temp would go down and it would be "fine". 2 weeks ago i was at a stop on a hot New Mexican day and my car overheating way to much and the radiator hose popped off and all my coolant dripped out. my radiator is messed up and well my auxiliary fan doesn't come on at all anymore. should i replace those 2 things with thermostat and coolant change? or fix the entire cooling system, i know the cooling systems aren't the best on the car but the owner did claim he replaced it, the guy before me definitely took car of the car, plenty of receipts which i will be going through, and the car hasn't skipped a beat for me. i'm at a point of saving right now cause i know it will be around 600-700 to redo the system but i know my car will be better after.

I think we're making a lot of assumptions here. Especially if you don't have any money, slow down and look at what's actually wrong here.

It may have originally just been low on coolant due to having the cooling system recently replaced. I would view that as a relatively minor issue, and not really connected at all to the other problems caused by damaging the auxiliary fan and having the main fan clutch dead.

You broke your auxiliary fan (which is, you know, AUXILIARY - it's the backup fan), and now you overheat when you stop. Which means your main fan was dead before any of this started.

So first, get your fans fixed - both of them. You can get a new aux fan for not too much, and a new main fan for pretty cheap. The body damage you caused may make the aux fan replacement more work than it would otherwise be, but that should be your second order of business (It might even just be unplugged, since the plug is at the bottom of the aux fan, on the driver's side. plugging it back in - or even fixing the wires if they got ripped out - would be roughly zero cost to you).

Get the main fan working first - it's likely the clutch on that main fan that's dead. That may be your only urgent expense - everything else can wait while you save up for it, especially if the PO says it was all redone (and that goes double if you can verify this in your receipts). If you can only do one, the original factory fan that mounts to the water pump is the place to start (and it's cheaper anyway). Your PO may have even replaced that main fan with an electric one. Whichever it is, get your fans working - starting with the main fan.

Second, check your radiator and hose for damage that may have caused the hose to come off. It is not TOO abnormal to pop a hose off when you overheat, especially if wasn't as tight as it could be due to recently having been replaced.

Third - yes, these cars can be sensitive to overheating. You should not be shrugging it off when the car's temp needle moves past the 12 o'clock position - you should be shutting it down and figuring out the problem. This is how head gasket problems are born - which is almost certainly not something you can afford right now. Stop driving your car until this is sorted, or if you can't (it's your only car), drop anything that isn't essential and sort it out now.

Most cars these days are appliances. These are not. I like to compare these cars to airplanes, or maybe a pet tiger. They are reliable as long as you are reliable with them. When you ignore stuff like this, it will bite you - and tear you up. Owning and driving one of these requires responsibility. Otherwise, you'll be one of those guys like that Car Throttle a$$hat who talks about what a POS his old M3 is. You ignore a $100 problem (a bad fan) and create a $3000 problem (a blown head gasket).

If you're lucky, you haven't warped the head / killed the head gasket and 2 new fans and a hose clamp will get you back on the road for under $200.

[realjones]

Instead of completely overreacting (pulling the head sheesh) why don't you see if you can stop the clutch fan from spinning with a newspaper or magazine? If you can, it's dead and needs to be replaced. This is very likely if car heats up a lot when not moving much and is probably more pronounced now that your auxillary fan isn't working (which used to come on and save your butt). Very easy fix which may solve all your issues.

Agree with the above guy that the main clutch fan was probably your original issue...do the fans first.