Otto Maddox
Otto Maddox Dork
7/19/11 10:58 a.m.

About what year did BMW stop making cooling systems that self destructed in short time? Is the 2006 and forward 3-series cooling system reliable or is it still a replace the whole thing around 80K kind of deal?

oldtin
oldtin Dork
7/19/11 11:35 a.m.

They haven't stopped building the self destruct cooling systems. Started with the e36 using plastic components and fittings. Even water pump impellers. The plastics are still in use, so I would expect it to continue to be an issue. E90/92s still have a lot of plastic in the cooling system. Maybe it's better, but I woundnt count on it.

02Pilot
02Pilot Reader
7/19/11 11:47 a.m.

The plastic started earlier than that. Late E21s, all E28s, and I believe most other cars of that vintage (early 1980s) already had plastic radiator tanks. Later cars just added plastic in new areas.

nderwater
nderwater Dork
7/19/11 11:51 a.m.

The fan in one of my E30's liked to eat radiator hoses on track.
PS - Antifreeze makes a terrific tire lubricant.

ansonivan
ansonivan Dork
7/19/11 12:20 p.m.

The 06+ cars with the 6 cylinder n5x engines seem to be pretty well cured of the old problems. They do have an electric water pump which can fail expensively. Interestingly enough, even though the dme will store a code for water pump failure the cluster will not notify the driver until the engine gets hot.

The new v8's suffer from new and even more expensive cooling system failures.

dj06482
dj06482 GRM+ Memberand HalfDork
7/19/11 12:35 p.m.
nderwater wrote: The fan in one of my E30's liked to eat radiator hoses on track. PS - Antifreeze makes a terrific tire lubricant.

Worn motor mounts?

nderwater
nderwater Dork
7/19/11 12:38 p.m.

In reply to dj06482:

Hard shifting & soft mounts. The coolant hoses were rerouted on 88+ E30's.

Giant Purple Snorklewacker
Giant Purple Snorklewacker SuperDork
7/19/11 1:34 p.m.
nderwater wrote: The fan in one of my E30's liked to eat radiator hoses on track. PS - Antifreeze makes a terrific tire lubricant.

It ate a motor mount sometime before that

Giant Purple Snorklewacker
Giant Purple Snorklewacker SuperDork
7/19/11 1:49 p.m.
Otto Maddox wrote: About what year did BMW stop making cooling systems that self destructed in short time? Is the 2006 and forward 3-series cooling system reliable or is it still a replace the whole thing around 80K kind of deal?

Honestly, you are not replacing the entire thing for any reason other than convenience. The hoses are good for 150k. It is a t-stat, water pump, radiator and expansion tank. It isn't an automatic knee-jerk at 80k either. If the plastic seems to be getting brittle on the hose necks or bottle - change it. Buy good brand names (not chinese knock-offs with German names). If you take the pump out and the bearing is good and the plastic is supple - put it back in. It isn't a big job - you can pull the whole thing in an hour. The deal is that a lot of folks don't want to check the water necks and such every time they change the oil so they drop $450 every 80k to be sure. Not a bad deal all things considered.

If you want to be super-sure, drop a bit more and do a Stewart Warner pump, metal t-stat housing, and an aluminum radiator and then all you have to ever do again is the t-stat.

pigeon
pigeon Dork
7/19/11 2:04 p.m.

My former '99 328i went about 150k miles on the original expansion tank and had 168k on the radiator when I sold it. I had replaced the water pump as preventative maintenance and that failed within 10k miles. Luckily I had the old, original pump still on my shelf and threw that back in where it was happily spinning away when the car was sold. The hoses were all original and fine too. T-stat was never changed. The car was not babied either. I bought it with 100k miles from the second owner, who bought it as a CPO with something like 20k miles on it, and got all of the service records from BMW on purchase - there wasn't much. In the 68k miles I had the car I regularly autocrossed it and generally drove it like I stole it. But who knows, mine is just one data point.

chandlerGTi
chandlerGTi Reader
7/19/11 2:21 p.m.

My take is that if you flush the coolant regularly than the plastic parts last longer.

Joe Gearin
Joe Gearin Associate Publisher
7/19/11 2:42 p.m.

My E36's cooling system was operating perfectly when a large raccoon decided to commit suicide by jumping in front of the car at 85+ mph. (the car had 110,000 at the time)

The hit didn't hurt any sheetmetal, but did get me a new radiator / waterpump / airdam from the insurance.

80K seems early unless you are in AZ, NM, TX or another very dry climate.

02Pilot
02Pilot Reader
7/19/11 3:00 p.m.

The other factor in the equation is the size of the engine relative to the engine bay. The I6 engines, especially in the larger 5-series engine bay, tend to be less prone to failures than the V8s, which are much more tightly packaged.

I consider it a 100k maintenance item on an I6, 80k on a V8.

dculberson
dculberson HalfDork
7/19/11 3:13 p.m.

A plastic water pump impeller isn't necessarily a bad thing. My wife's LS400 had the original water pump on it when I bought it, it had 239k miles on it. Those have plastic impellers as well. (The date code was clear, made in 1991 like the rest of the car. Impressive.)

Ian F
Ian F SuperDork
7/19/11 3:31 p.m.

It should also be noted that BMW's (as well as every German car I've come across) seem to be intolerant of crappy coolant. It seems you'll get the most reliable results using dealer-sourced coolant mixed with distilled water. Or for a track car, distilled water only w/ maybe water wetter.

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