busted leveling switch in expansion tank - problem?

[KevinC]

So last night I fired up the heater in my ZHP, a very rare occurrence. Moments later, my coolant level idiot light came on. This happened a couple of summers ago out of the blue. I topped up with a bit of distilled water, haven't seen any light since.. till last night.

So tonight I check the coolant level, sure enough it's low, and I added about 10-15 ounces of distilled water, till the float switch thing popped up (#5 in the diagram below).

http://realoem.com/bmw/diagrams/u/y/262.png

But then the cap wouldn't go back onto the expansion tank, as if it were hanging up on something. Took it back off, found this at the bottom of the filler neck...

http://www.kcphotodump.net/Cars/BMW-330Ci/i-cjFm7mC/0/L/IMG_5668-L.jpg

That piece had busted off. I managed to fish it out of the bottom (wasn't easy!) and get the tank closed properly. Do I need to be concerned about replacing the thing right away? It's not an expensive part, and part of it is still attached, but not sure if I need to deal with it immediately or not. Advice?

[ELCID86]

I'm glad you got it out! Are you on the original ET? That float rod has bad color deterioration. Bruce tells me that's a sign it's time for a new ET.


Thumbs, iPhone, Tapatalk.

[KevinC]

After posting that and reading some other cooling system threads, I decided that I'd do a minimal cooling system refresh. I'm at 76k miles and I'm sure that tank is original. I'll replace it, the water pump, and the large hoses, and possibly the thermostat, if my indy thinks I should.

[stephenkirsh]

Yes on the thermostat. That was the first thing that failed on my cooling system. It even failed before the expansion tank!

[ELCID86]

+1 on thermostat. Do the tensioners and idler pulleys too. I guaranty at least 1-2 will be bad. Ask Daniel who only has 65ish k on his '05.


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[KevinC]

Dropped the car at my indy today, as he was working on a BEAUTIFUL '72 '02 that was once his project, now belongs to a customer. He said nyet to both the thermostat and water pump, saying he sees virtually zero problems with them at this age on E46's.. unlike the crappier water pump on the E36, which he acknowledges is a turd. So it'll be new expansion tank, new plastic cowl cover thingie under the windshield that always disintegrates after a few years, and back on the road I'll go.

[KevinC]

Interesting comment on the tensioners & idler pulleys being toast at 65k. Why should I assume that mine should fail so early too? Is there a documented history here (ZHPM) of more similar failures at similar mileage, or just this one mentioned? If so, I'll call him back and have him do them too.. though I tend to trust his years of wisdom, and he's telling me not to sweat the other stuff.

[danewilson77]

Interesting comment on the tensioners & idler pulleys being toast at 65k. Why should I assume that mine should fail so early too? Is there a documented history here (ZHPM) of more similar failures at similar mileage, or just this one mentioned? If so, I'll call him back and have him do them too.. though I tend to trust his years of wisdom, and he's telling me not to sweat the other stuff.
It happens, a lot. 65k may be a tad premature, but you're coming up on failure point. Batteries are about a 5-7 year swag, along with some other e46 common failure items.

"No flamesuit required"

[stephenkirsh]

I'm shocked he said no to the thermostat. I thought "conventional wisdom" had us doing the whole cooling system at once, together, instead of piece mealing it.

A pulley on my dad's N52 was already starting to go at 50k. Two of mine were done at 98k on my e46 325. They just suck.

[danewilson77]

I'm shocked he said no to the thermostat. I thought "conventional wisdom" had us doing the whole cooling system at once, together, instead of piece mealing it.

A pulley on my dad's N52 was already starting to go at 50k. Two of mine were done at 98k on my e46 325. They just suck.
Right. No biggie. To each their own. Kevin knows his shit.

"No flamesuit required"

[Whammy]

After posting that and reading some other cooling system threads, I decided that I'd do a minimal cooling system refresh. I'm at 76k miles and I'm sure that tank is original. I'll replace it, the water pump, and the large hoses, and possibly the thermostat, if my indy thinks I should.

Replace the thermostat. You're right there. It'll cost you $60 from ecs.

[KevinC]

Right. No biggie. To each their own. Kevin knows his shit.


I don't know dick! Everything I know, I learned on the interwebs. I trust you guys as a group, but I do trust my indy as well - he's quite revered here in town, and he's got a TON of experience, and he's the only one who's touched my cars for a few years now. I like that he's a bit on the conservative side with his recommendations - yet he won't hesitate to suggest something be done if his own personal experience deems it necessary. He's pretty bullish on the E46 cooling system being pretty solid, while readily acknowledging that it was a notorious weak point in the E36. And here in the Sonoran desert, if a cooling system is weak, it ain't gonna last, that's for sure.

He'll call me tomorrow to give me an estimate, and I'll ask him again about about the thermostat and tensioners/pulleys, mentioning the concern expressed here. I'll report back on how it all turns out. Thanks for everyone's input!

[danewilson77]

He's pretty bullish on the E46 cooling system being pretty solid....

No offense, but I'd look for another indy if that was the first thing they told me they were "bullish" on. I know you have history with this guy though, so I understand your willingness to work with him.

It's well documented that the coolant system on these cars require micro management. Expansion tank, temp sensor oring leaks, thermostat and water pump failures are too numerous to count.

I'm floored he's bullish on this.

"No flamesuit required"

[KevinC]

"Bullish" is my own term. As for the water pump specifically - where's the hard evidence that it's a turd? I've read plenty of paranoia over the past couple of years since buying this car, but not much that sounded well-founded. I haven't seen any hard numbers on failures. Lots of preventative replacements, but not many reports of "my water pump just died at 50k and left me stranded, O my!!" type of thing.

Look for another indy? Insane. If you had any direct experience with the guy, I'm pretty sure you'd agree with me.

[danewilson77]

Ok. Sounds good. No arguing from me. I'm sure it will work out for you.

"No flamesuit required"

[stephenkirsh]

Honestly, the water pump is the one component I have not heard of failing. EVERYTHING else in the cooling system has. Hoses, radiator, thermostat, especially the fan temp sensor and expansion tank. But I say replace the pump because you're replacing everything else anyway. Just do it all at once so it's easier to keep track of. Once every 100k isn't too insane I guess.

[NorCalZman]

Ok well at 90k my ET was showing signs of impending failure. Around the same time I found that my water pump had been leaking coolant through the shaft. Dried coolant was crusted onto the unit.

I am with everyone else on the preventative maintenance. I would have to replace half of it only to have to go back into it to do the other half 25k later.


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[fredo]

Mi Indy refreshed the coolant system on my 323i e46 at 145k miles. For some reason, he didn't replace the water pump. The WP failed less than 5k miles later. Luckily for me, this happened after I sold the car.

[kayger12]

"Bullish" is my own term. As for the water pump specifically - where's the hard evidence that it's a turd? I've read plenty of paranoia over the past couple of years since buying this car, but not much that sounded well-founded. I haven't seen any hard numbers on failures. Lots of preventative replacements, but not many reports of "my water pump just died at 50k and left me stranded, O my!!" type of thing.

Look for another indy? Insane. If you had any direct experience with the guy, I'm pretty sure you'd agree with me.

Over the years the boards have been chock-full of water pump failures. Also talk to any BMW tech who was around in the heyday of the E36 and E46 and they'll fill your afternoon with failure stories. The 60k mile replacement suggestion comes from Mike Miller, but I'd imagine there are many other techs who would agree with that schedule. I'm guessing the failures are now much less frequent on the boards as most people who frequent the boards have embraced the preventative maintenance approach to the cooling system.
http://www.m3forum.net/m3forum/showthread.php?t=338369
http://www.bimmerfest.com/forums/showthread.php?t=513903

[kayger12]

I'm shocked he said no to the thermostat. I thought "conventional wisdom" had us doing the whole cooling system at once, together, instead of piece mealing it.

A pulley on my dad's N52 was already starting to go at 50k. Two of mine were done at 98k on my e46 325. They just suck.

Piece mealing is actually the OSMS reccomendation:

I recommend the following preventive replacement schedule for the cooling system on
this car:
Every 60,000 miles: water pump, thermostat, plastic thermostat housing if so equipped
(or replace it once with the aftermarket aluminum thermostat housing)

Every 90,000 miles: radiator, expansion tank, fan and fan clutch if so equipped (for cars
you’re going to keep forever, consider using the all-aluminum radiator and expansion
take from www.zionsvilleautosport.com and you won't have to do it again at 180,000)

Every 150,000 miles: all coolant and fuel hoses

Every two years: drain and fill coolant, including draining the engine block by opening
the drain plug on the right side under the exhaust manifolds, replace using fresh original
BMW anti-freeze mixed 50-50 with distilled water

[Whammy]

I don't know dick! Everything I know, I learned on the interwebs. I trust you guys as a group, but I do trust my indy as well - he's quite revered here in town, and he's got a TON of experience, and he's the only one who's touched my cars for a few years now. I like that he's a bit on the conservative side with his recommendations - yet he won't hesitate to suggest something be done if his own personal experience deems it necessary. He's pretty bullish on the E46 cooling system being pretty solid, while readily acknowledging that it was a notorious weak point in the E36. And here in the Sonoran desert, if a cooling system is weak, it ain't gonna last, that's for sure.

He'll call me tomorrow to give me an estimate, and I'll ask him again about about the thermostat and tensioners/pulleys, mentioning the concern expressed here. I'll report back on how it all turns out. Thanks for everyone's input!


"Bullish" is my own term. As for the water pump specifically - where's the hard evidence that it's a turd? I've read plenty of paranoia over the past couple of years since buying this car, but not much that sounded well-founded. I haven't seen any hard numbers on failures. Lots of preventative replacements, but not many reports of "my water pump just died at 50k and left me stranded, O my!!" type of thing.

Look for another indy? Insane. If you had any direct experience with the guy, I'm pretty sure you'd agree with me.

Here is my question to you: Why don't you do this work yourself versus this indy?

I ask this question because I just did this procedure myself. I am not the most mechanically inclined however I am able to do it.Tools needed were car ramps, a bucket for coolant, socket set, screwdrivers (flathead & phillips) and a torx socket set. It is not hard and if I lived near I would do it for you for a really good bottle of whiskey (bourbon, rye or scotch) or really, really good beer.

DIYs are out there and it is fairly easy.