[apascutia]

Hi everyone,

Last Friday, my WP/Thermostat stopped working. Car is an 06 330xi with around 87k miles. AFAIK, they're the original components on the car. I was able to pull over into a parking lot once I got the first warning (yellow warning - engine temp high), and I shut the car off and opened the hood. The fan ran for about 5 min after I shut the car off. I was lucky as I was only a few minutes away from home. I let the car cool for about 30 min and I was able to make it home before getting another warning about temp or the fan starting again. I arrived home and the car seemed fine otherwise. After a few hours, I checked the coolant level and it was the same as before, so I wasn't low on coolant when this happened. Also, the color of the coolant was just as it was before (blue).
Things to note:
1. The first warning that something wasn't right was that the radiator fan started going nuts. It was 35 degrees out and I didn't have the AC on, but I noticed it was pretty much maxed out when I stopped at a red light right before I got the yellow temp warning.
2. The 2nd thing that happened before I got the yellow warning was my heat suddenly turned cool. I was no longer getting heat in the cabin.

Here's the frustrating part: I knew that the water pump/thermostat had to be replaced soon, as they were original, and I've been getting shadow codes (water pump speed deviation) from the pump for a few months now. I urge anyone who owns an E90 (or any BMW for that matter) to have a more advanced code reader/INPA, as mine made me aware of these issues months ago. As I'm working mostly from home and I've been driving way less, it wasn't the most pressing thing on my mind. My fault for not replacing them before, and I was lucky that I was so close to home. Moral of the story is pay attention to your car, because it warned me now for quite some time that these items needed replacing. Also, I'd love to have a talk with the genius that decided to do away with a coolant temp indicator on these cars.

[ryan stewart]

Yeah this is why I'm an advocate for replacing the damned thing early. The moment you get any code or odd behavior to just pull the trigger. It seems like 100k is the "life" of these things.

[apascutia]

Originally Posted by ryan stewart

Yeah this is why I'm an advocate for replacing the damned thing early. The moment you get any code or odd behavior to just pull the trigger. It seems like 100k is the "life" of these things.

Yup! It's nice that you can find out ahead about these things so you don't get stranded far away from home. I'd highly recommend to anyone that owns these cars to have some sort of method of pulling codes. It'll save you, plus it's nice to know more details about how the car's doing overall.

[TemjinX2]

on the n54s the water pump dies around 65-75k. electric pumps sound good in theory until your stuck on the side of the road

[Jorow99]

There is a reason Toyota ditched BMWs electric water pump for a mechanical one in the Supra

[mainbearing]

^ I think that was because the B58 engine was used in the Supra instead of the junk that were the N54 and N55 (when BMW was learning how to turbo).

There were some real clueless BMW engineers who thought electric pumps were a good idea. They should have run the idea through Toyota engineers first.

Check out VehicularDIY's video here:
https://www.e90post.com/forums/showt...php?p=28147394

[apascutia]

Originally Posted by TemjinX2

on the n54s the water pump dies around 65-75k. electric pumps sound good in theory until your stuck on the side of the road

Exactly. Most people don't know that it can spit out codes before actually going out. It's a gamble in this mileage range if it hasn't been replaced before.

[hassmaschine]

the replacement N52 pumps will last for way longer than 100k miles (heck, even the original went to 130k in my car). I think we have a couple people here with over 200k on a replacement pump now.

The poor N54/N55 guys are stuck with the plastic pump housings so they end up breaking before the actual pump fails. I thought I saw a little while back an aftermarket pump was coming out with a metal housing, not sure if that ever happened or not.

no water pumps last forever - mechanical or otherwise. I just don't get that line of thought. Most mechanical pumps need replaced ever 100k or so, sometimes they lasted for even less (50-60k). A replacement N52 pump might need replaced - never? Toyota recommends the Camry get a new pump ever 100k miles, so how is that any different or better?

[ryan stewart]

Originally Posted by mainbearing

^ I think that was because the B58 engine was used in the Supra instead of the junk that were the N54 and N55 (when BMW was learning how to turbo).

There were some real clueless BMW engineers who thought electric pumps were a good idea. They should have run the idea through Toyota engineers first.

Check out VehicularDIY's video here:
https://www.e90post.com/forums/showt...php?p=28147394

Im guessing the primary reason was the real driver behind the electric steering, getting every last little bit of mileage out of them for CAFE. Not having something running on a belt all of the time (even if clutched) might get a half MPG or some small number that adds up.

I will admit I do like my REST function, I use it quite often. I just wish the OE ones were more robust electronically and not just shut off. Bearing noise should be your first clue (kind of like a slow leak/wobble helps you notice the mechanical pump going).

[Hoody007]

I must be extremely lucky… 140K miles on (I assume) the original water-pump / thermostat. No shadow codes either…

That being said, can you view the build date of the pump in ISTA? Could’ve been replaced before I bought it, and I’ve always been curious...