E46 M3 Cooling System lifespan?

[scubastove]

After reading and re-reading the service records of my 2002 M3, there's no record of any cooling-related jobs being done by the previous (and original) owner of my car. I have no records of any coolant flush, hoses, thermostat, nor water pump being replaced on the car.

When I originally purchased the car, the garage that performed the PPI mentioned that the car had its original water pump. I'm not sure how they could verify that without having opened up the accessories of the engine given that the water pump is embedded in the cylinder head behind everything.

But alas, I have all the service records and nothing pertaining to anything cooling related. At the bare minimum, I want to flush the coolant. But is that all I should do, or should I look into overhauling the whole cooling system? New pump, thermostat, possibly new radiator?

I don't believe my car could have the original coolant from 2002, that would be wild. Wouldn't the coolant have gelled up over all the years?

Or could it possibly just have been using distilled water? I'll check tomorrow... if so, a change for antifreeze would be a must on the east coast.

A bit more info, the car has 120k miles, was always garaged in California and I shipped it to the east coast this year.

All that being said... I've put roughly 3k miles on it and it has no problem staying cool or at normal operating temp.


Thanks for any advice.

[Lukem3]

I forgot which interval but coolant on our cars is every 30 or 60k. Don't remember. Regardless cheap insurance if u have no history just get it flushed. New thermostat doesn't hurt, check the waterpump bearing for wear

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[ViN]

I just did the entire refresh at 80k. The thermostat went and I just didn't want to take any chances based on what I've read and heard. I think if your budget allows it, I would suggest just getting it done.

[Lukem3]

I did aswell around the same milleage but it's not cheap. I did new overfill tank, hoses, thermostat, waterpump, all gaskets and the lower sensor. I think all together it's around $500 in parts if u go oe

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[EthanolTurbo]

I think I saw you post this on Facebook but I'd recommend just refreshing it when you have time. Better safe than sorry.

[Bostonbruck]

My water pump seal went out at 115k. Leaked coolant everywhere. People say the radiator will last longer then 100k especially if you don’t track the car but you might as well replace it for peace of mind.

[Rkymtnrider]

I got a full kit from getbmwparts.com it had everything except the additional reservoir. All O.E parts

[Andrew 06M3Cab]

I want to do this in the spring. I'm at 120k miles, and all I have replaced over the years is the thermostat. But this makes me think, on the old forum, there was spreadsheet that had for many many parts what the OE manufacturer was. In the case of the water pump, does anyone know if it was Saleri? Or better yet, does anyone have a copy of that spreadsheet?

[mpower22]

You should be ok because the car is still running, but look in the expansion tank with a flashlight. Gelling is much less of an issue these days with the advancements in technology, even for coolant additives. Range Rover now only recommends a 10 year change. Officially, BMW requires it every 4 years on the E46, regardless of mileage, but I wouldn't be surprised if the newer ones are longer intervals. Flushing it should be a first priority if you're not sure when it was last done. I would def change the water pump too. You should expect to get 80k - 120k out of it on average. You can grab it and try to pull up on the shaft to see if there's any bearing play, but if you flush the coolant now, you'll have to do it again once you do change the pump later so best to take care of it now. Another must-change item is the fan clutch. Those are known for locking up at higher mileages and then will spin at full engine RPM once that happens, and a fan blade or two will cut through the hood, which I've seen happen a few times on other e39 and e46. Some people worry about the expansion tank or radiator being replaced because of the plastic components and engine heat cycling, but I didn't replace those items. I also pop the hood in the summer to let the heat out of the engine bay to minimize degradation of the plastics under the hood.

I want to do this in the spring. I'm at 120k miles, and all I have replaced over the years is the thermostat. But this makes me think, on the old forum, there was spreadsheet that had for many many parts what the OE manufacturer was. In the case of the water pump, does anyone know if it was Saleri? Or better yet, does anyone have a copy of that spreadsheet?

The OEM for the pump is Laso IIRC.

[Obioban]

100,000 miles is a good interval if you don't want to risk a break down, but these cars are getting old enough that it might be time by age, even on low mileage cars.

[mrgizmo04]

I want to do this in the spring. I'm at 120k miles, and all I have replaced over the years is the thermostat. But this makes me think, on the old forum, there was spreadsheet that had for many many parts what the OE manufacturer was. In the case of the water pump, does anyone know if it was Saleri? Or better yet, does anyone have a copy of that spreadsheet?

https://docs.google.com/document/d/1...t?usp=drivesdk

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[Ceelooboob]

I refreshed my entire cooling system at around 90k and everything was in surprisingly good condition. I’m not 100% sure the entire cooling system was still the original parts from new but it didn’t look like anything was changed. I did mine preventatively.

[90mtx]

100K miles plus or minus 10%. And when you do purchase everything, your water pump will start leaking the day you are starting your work to let you know it is ready!

Jonathan

[Andrew 06M3Cab]

https://docs.google.com/document/d/1...t?usp=drivesdk

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Thanks! It's a great resource. Somebody should sticky it.