Stage 3 Cooling System Refresh for 128i or not?

[rhop101]

Hi Everyone,

I recently purchased a 09 128i 6spd/sport package with 135k miles as a DD with an occasional autocross or once a year track day thrown in. I've begun to go through the car and replace filter/fluids/etc , ordering parts from FCP Euro as I go for their awesome warranty.

Sometime this winter I plan to do a Cooling System Overhaul on the car and I was trying to Gauge how far I should go since my car has as many miles as it does.

I'm going to do the water pump/thermostat at least of course as I dont think there were replaced recently, but I'm not sure how much further I should go?

I've read I should go ahead and do the expansion tank and the radiator, but then I feel I ought to the equivalent of a might as well do all the hoses and sensors too just as preemptive maintenance.

There are multiple stage kits for the 135 models but not really any kits for the 128i beyond the basics. And I didn't see a post like this for the 128s after searching the forums.

Do you all think its worth the effort to put together a list of parts equivalent to Stage 3 refresh and execute it at my car's mileage or just do a normal water pump refresh and don't worry about it?

Am I just being paranoid since I've heard many a tale of split expansion tanks, blown radiator caps and snapped fittings? Naybe I'm just spoiled by my Honda S2000 which is at 200k with an entirely original cooling system and no leaks or issues and even then all I have to do is maybe replace the radiator soon if its starts leaking.

I'm sure making a list would be super beneficial to all us 128 owners out there as there really isn't one.

Thanks for your responses!

(Edit: Turner Motorsports seems to make a kit with some hoses optional: https://www.turnermotorsport.com/p-3...kage/?pdk=AgEB

It suggested replacing 4 of the hoses, connected with the water pump and radiator to engine connections, but ignoring the expansion tank hoses)

[desertman123]

Nah don't worry about it. I'd say order some hoses individually, especially the ones that connect to the pump/thermostat, but don't bother with the expansion tank and radiator. A bit more robust than it was on E46

[rhop101]

Well Time for the aftermath!

As of this writing I am about 70% complete the near equivalent of a stage 3 overhaul and replacement of most of the other fluids in the car, still waiting on a new pump to thermostat hose to come in and one or two other things to finish and then add coolant etc. I have about 15 hours or so of work into the cooling system overhaul.

Maybe in a more stable climate like you have in Orlando Desertman123, you could get away with putting off replacements.

I did decide to replace most of the hoses, radiator, expansion tank plus some of the fasteners and clamps. I could have forgone the expansion tank most likely and I actually ended up returning so extra parts I had bought just in case.

The good news:
For all the people that have issues with water pumps failing my 140k mile 7 year old 128i has the original pump and thermostat and it still worked fine. So maybe the water pump breaks everytime you bat an eyelash deal is kinda overhyped in any case I plan to replace it again soon after the 200k mark in a few years.

I won't have to mess with the cooling system at all for 6 or 7 years if I end up keeping the car that long and run it into the ground.

This was the first time I peeled back the aero panels on my car and really surveyed its condition and I found no leaks from the engine anywhere. I had some oil leaks repaired just before buying the car and I got to work on some other things at the same time.

Did a brake, tranny, and diff fluid replacement while I was at this. My drive belt and pulleys were fine so didn't worry about them.

The Bad News:
Once I got into replacing things, it was like opening a can of worms and boy was it nasty and a little disturbing. Because my cooling system had never been touched ever, I ran into issues with broken brackets and snapped and stuck hose fittings.

If anything this all should have been done much sooner maybe 100/120k miles. I found that the 3 mounting brackets for the heater core return line had all snapped off. In the process of removing the fan shroud to access some of the mounting bracket bolts, the radiator overflow snapped off. Good thing I was replacing the radiator anyway.

I also found 1 or 2 of the hoses had evidence of dry rot, a cracking sound when I squeezed. The more important of which was the oil cooler hose. Though most hoses seemed fine. Just replacing them all but the heater core hoses just in case and they aren't that much money. Also found the gasket on the engine outlet to pump line was brittle so I went ahead and replaced the whole thing seal, hose and all.

Pretty much all of the large quick-disconnects were seized and required cutting of hoses to extract. Once again glad I was just replacing the radiator and the thermostat(the squid) so I didn't have to deal with it. Thankfully the Engine inlet line came free after putting my body weight into it XD.