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Thursday, February 29, 2024

Doug's Domain

Doug Vetter, ATP/CFI

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May 24, 2006

I took the car in for a major service today. We did a ton of things and I only had one surprise (unfortunately, it was a biggie). First, the things I planned to do:

Oil Service

Nothing much to report here. Just a routine service.

Brake Fluid Flush

(Image: BMW Composite Impeller Water Pump)BMW specifies brake fluid flushes every two years. I usually grind through a set of brakes in that time and just combine the flush with the brake job, but because the car sat a lot last year while I owned the RSX, I got a bit out of sync and I exceeded the calendar time limit by almost six months. No big deal, really, but the fluid is the lifeblood of the brake system.

Flushing the brake fluid enhances braking performance under extreme conditions (like deer avoidance) and is very cheap insurance against caliper damage, so I figured I'd do it in advance of the next brake job.

Based on what I can see, the fronts probably have around 5K to go, while the rears (with more than 60K on them now) may actually go a bit longer. I would very much like to do the brakes myself this time around because I need to learn more about the process as well as save some coin, but my schedule will have a lot to say about that.

Coolant Flush

I'd flushed my coolant last year, but when you put spend hundreds of dollars on new parts, you don't cheap out on a gallon of coolant and a gallon of distilled water. 'Nuff said.

Water Pump

This is the primary reason why I brought the car in. BMWs have a long history of problematic water pumps. On some units the impellers would just snap. On others, the bearings would fail, sending the fan outside of its normal plane of rotation, causing it to self destruct as it hit the radiator, among other things.

The currently-shipping pumps have what BMW chooses to call a "composite" impeller. When I hear "composite", I think plastic or fiberglass, but I'm here to tell you that even though the impeller looks like a common injection-molded plastic unit, when struck with a finger it rings like a light metal (magnesium or the like). Hopefully this will mean long life. Guess I'll find out.

Thermostat & Housing

This was a "while in Rome" fix. I'd replaced the thermostat once before when the original failed at around 60K miles. Given I now have 128K on the clock, it seemed wise to replace it again. Since we had to remove the thermostat housing (BMW refers to it as a "connection flange") to get to the thermostat, and the flange is made of a hard fibrous plastic (looks a lot like Bakelite) that has been subject to MANY heat cycles, I decided to swap that out for a new part as well.

(Image: Idler, Tensioner and Protective CapHoses

My technician was out on the day I ordered the parts for this little maintenance binge, so while we originally discussed replacing only the upper and lower radiator hoses, I ordered them all and had them installed today. All coolant hoses are now brand new and ready for another 120K+ miles.


Since the belts must be removed to do the other work and I noticed that the back side of the A/C belt was split in several places I decided to swap those out as well. The belts were done around 45K miles ago, which isn't very long in the grand scheme of things, but I've been told that's a pretty typical life span for serpentine belts.


These units consist of a sealed bearing and a plastic pulley. They each come with a dust cap. The upper tensioner (near the alternator) had lost its cover at some point. While the bearing is sealed, the outer edge of the bearing surface had rusted over. Left alone, I knew it would cause problems, so I decided to replace them both. Note that I chose not to replace the hydraulic cylinder associated with the A/C belt tensioner because my technician said that while the older mechanical variety were a "hot item", the hydraulic units have proven virtually bulletproof.

Fuel Filter

I have to admit I have no idea when this was last replaced. My technician said he remembered replacing it at one of the inspection II's but I don't remember seeing it on any invoice. So the filter on the car had either ~65K or 128K miles on it. Either way, it had been way too long, so it was time to replace it.

(Image: Fuel Filter) Replacing the fuel filter is a relatively simple DIY task that is needlessly complicated by its location under the car. The car must be on jack stands or (wait for it...) on a lift to do it in a reasonable time. Needless to say, this was a bit out of the scope of the work I'd planned but my tech offered to swap it out for me.

Now for the surprise.


I expected a labor bill for around $500 for the installation of the parts I purchased earlier at nearly $350 when I got the call. My service advisor told me that my technician removed the hoses and found the inner surface of the radiator necks deteriorating. He recommended we replace the radiator for obvious reasons and I was not about to doubt him. In fact, I'd considered replacing it as part of this preventative maintenance binge but didn't want to bite off more than I could chew. So, the good news is that I have completely overhauled my cooling system just in time for summer. The obvious downside is it cost me around $1400 to do it.

The funny thing is that the dealer is on my way to work, and between chatting with my technician and ordering the parts, I'd become quite a fixture around there the past couple of weeks. One of the techs asked me if I intended to pay rent. I respectfully declined. :-)

Parts: $685, Labor $675, Total: $1443, Mileage: 128003.