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      05-29-2012, 09:50 PM   #70
First Lieutenant

Drives: 2011 E93 335i - N55
Join Date: May 2007
Location: Baltimore, MD

iTrader: (0)

Originally Posted by ENINTY View Post
I guess so, but I'm disappointed a bit about the engineering. I get it, the water pump has a tough job. It has to push very hot water around for long periods of time. BMW's idea about using an electric water pump is a good concept, but poor in execution on their part. First off there are no warning signs (other than the fault codes - but how many owners except a gearhead like me would ever know they are there), second there is no water temp gauge to keep an eye on engine temperature (yes the 335i has an oil temp gauge, but that'll not do you any good to indicate a pump failure), and finally the over temp warning is almost after-the-fact; my car literally when from normal condition to overheating (red indicator symbol) in about 5 seconds. If I was stuck in traffic, say in the center lane of a 4 lane freeway, I can't imagine how much engine damage would have occurred. I was lucky because when my car indicated an over temp condition I was able to pull to the shoulder and shut the engine off in maybe 10 - 15 seconds. But I knew exactly what had happened because a) I knew my water pump was suspect (throwing codes), b) it was high-mileage, and c) I knew the conditions of over temp from reading the owner's manual and from threads on this Forum. The typical BMW owner knows none of these things and would let the engine seriously over heat, which could really damage the engine with a blown headgasket, or worse a warped cylinderhead (fingers crossed my car has no such problems).

It's a poor design. Most (belt-driven) water pumps have a weephole that begins too leak and provides a distinct smell of coolant to give you some time to have the car inspected and repaired before the pump fails. Other belt-driven pumps are driven from the camshaft belt and have a periodic replacement schedule that coincides with the cambelt replacement interval, so they rarely fail. And most belt-driven water pumps DON"T COST FUCKING $500. It's fine to design an electrically driven water pump, and it did go 150,000 miles (which is attributable to the fact it's not driven off a belt), but the pump also costs over 5-times as much as a conventional belt-driven pump, so where are the life-cycle maintenance savings I expected to get from this design. And there are no fuel cost savings (to the owner) because what ever fuel mileage is gained by driving the pump electrically is lost in the repair event. Even though the pump is a fancy electric motor driven design, it doesn't need to, and it shouldn't cost $500 (and the new unit is a remanufactured part to boot!).

The obnoxiously priced pump is what kept me from replacing it before it failed. Having a road-side breakdown cost me a towing bill of $200 (my insurance covers $100 of the total $300 bill). If the pump was reasonably priced, say $150, I would have replaced it when I did the thermostat back in February with 134K on the clock.

So if this happens to an uninformed owner, say a 34-year old young female executive who is concentraiting on her career and pays no attention to her car, she'd be out $200 for a towing charge, $500 for the part, and $500 for the repair labor. Think she'll ever by a BMW again when a water pump replacement costs $1,200 (even if it is covered under a warranty). I doubt it. BMW needs to rethink this design.

Considering how BMW is starting to go engineering-wise and build quality-wise, this will probably be my last BMW (and I've owned a 3-series since 1989). They are just getting too stupid with the over engineering.

Just my rant.
I completely agree with you and feel your pain. my 335i's WP just went out at 39K. so pissed. I am going to do it myself and I understand WP burn out but 500 for WP is ridiculous. E36 WP is only 200 for god sakes..

The forum needs to very detail and awesome DIY For this ...
********** 2008 BMW 335i TT******