Coolant light: just add more liquid, or is definitely worse?

[2004_blue_zhp]

Hey guys,

My (yellow) coolant light came on when I started my car this evening. It was cold out, and the light came on as soon as I turned on the heat. I turned off the heat and about 30 seconds later the light went away. Put the heat back on and the light came right back.

From googling around, it seems like the next step is to get my hands on some BMW antifreeze and mix it 50:50 with distilled water and then follow the procedure to confirm the cooling system has the proper amount of liquid in it. (Anyone care to recommend their favorite tutorial for this admittedly simple step?) This much I'm sure I can handle, but even before doing that, I wanted to confirm what the next steps would be once I've made sure the cooling system is appropriately filled.

If it takes 1 cup of liquid and is then full (and I can't see dried coolant anywhere in the engine bay), do I just keep driving and see if the light comes back? If it never comes back, do I just move on and forget this ever happened? What if it takes 2 cups? How much would it need to take to make you confident the problem was deeper than just "coolant needs to be topped up"?

My car is at 61k miles now, and as far as I know, the cooling system has never been refreshed. I'm guessing you're all going to suggest I go ahead and do that now. I'm not averse to that idea, but I don't have the time, space, or skill to DIY it. If I just go to the dealer and say "please refresh my cooling system" will they know what that means? What about "please replace my expansion tank, my water pump, my thermostat and associated hoses etc."? At the dealer, what would you expect that to cost? How much do you think it would be if I bought parts online and went to an independent mechanic? Anyone want to suggest a shop close to NYC?

Thanks

[Mtnman]

At 61k, just add some coolant mix and move on. Did u check the coolant stick in the radiator? I bet that measures low too.

[alexandre]

It's a little early for a cooling refresh replacement based solely on mileage, but the 8 year-old plastics are probably nearing the end of their life. Mileage is one thing, but this stuff needs to be replaced often because BMW uses cheap-a** materials. If you're going through big temperature differences (e.g. if you live in the North) plastics are probably getting worn quicker too. At $300-400 in parts, a refresh is cheap insurance. Maybe your expansion tank cracked (even if it's a hairline crack) and is starting to leak a little... I know delmarco's (he's well known at e46Fanatics) system completely failed at 55k or so - waterpump, tank, etc... on a 9 year-old car.

Dealer pricing is probably over $1k parts + labor. Best bet would be to buy the parts yourself (ECS Tuning, Turner Motorsport and getBMWparts all sell a great kit that has everything needed... Just go to a specialized BMW indy and give them the whole kit, they'll probably know what to do.

[nike001]

No, you don't have to do the cooling system overhaul now. But definitely plan for it later.

Your light came on because your heater core sucked in some coolant and that drop in fluid was enough to trigger your light. Add some water and button it up, you'll be good.

[kayger12]

Hey guys,

My (yellow) coolant light came on when I started my car this evening. It was cold out, and the light came on as soon as I turned on the heat. I turned off the heat and about 30 seconds later the light went away. Put the heat back on and the light came right back.

From googling around, it seems like the next step is to get my hands on some BMW antifreeze and mix it 50:50 with distilled water and then follow the procedure to confirm the cooling system has the proper amount of liquid in it. (Anyone care to recommend their favorite tutorial for this admittedly simple step?) This much I'm sure I can handle, but even before doing that, I wanted to confirm what the next steps would be once I've made sure the cooling system is appropriately filled.

If it takes 1 cup of liquid and is then full (and I can't see dried coolant anywhere in the engine bay), do I just keep driving and see if the light comes back? If it never comes back, do I just move on and forget this ever happened? What if it takes 2 cups? How much would it need to take to make you confident the problem was deeper than just "coolant needs to be topped up"?

My car is at 61k miles now, and as far as I know, the cooling system has never been refreshed. I'm guessing you're all going to suggest I go ahead and do that now. I'm not averse to that idea, but I don't have the time, space, or skill to DIY it. If I just go to the dealer and say "please refresh my cooling system" will they know what that means? What about "please replace my expansion tank, my water pump, my thermostat and associated hoses etc."? At the dealer, what would you expect that to cost? How much do you think it would be if I bought parts online and went to an independent mechanic? Anyone want to suggest a shop close to NYC?

Thanks

If you go buy the old school maintenance schedule, at 60K you want to look to replace the water pump, thermostat, and thermostat housing.

I suspect that at 60K if you're losing coolant it's probably weeping from the water pump or a crack in the thermostat housing. It's a sealed system, so it has to be going somewhere.

I wouldn't bother with the expansion tank or hoses at this point. It's not necessary unless you identify an existing problem with either.

Here's a helpful link for changing/adding coolant. (http://www.bmw330ci.net/maintenance/coolant.php)

Here's another link for reputable BMW indy shops. (http://www.bimrs.org/2008MapPage.html)

[BCS_ZHP]

It's hard to see the weep hole underneath the water pump to determine if that is the source of your leak. But if its all original, a cheap check after topping off the coolant level is to replace the expansion tank cap ($10). The rubber seal in that cap degrades over time and can let some coolant leak by. I have found this to be the cause of low coolant on a couple of e46swith lower mileage but over 6 years old.

[2004_blue_zhp]

Keith, you're getting at the issue I was alluding to in my original post. If its supposed to be a closed system, is it ever "really, truly, actually OK" to need to top off with a cup or two of coolant? Or is just "not that big a problem"? To have a dealer do the pump/thermostat/housing trifecta, what would you expect all in? What about at an indy?

[nike001]

Post #4

It's your problem I swear.

[BCS_ZHP]

Yes, you can add coolant. It the coolant was flushed previously and they didn't allow the air to bleed out of the system, then you likely had an air pocket in the system. So you turn on the heat, the coolant flows into the heater core where some air remains, the air is pushed out into the system where it eventually equalizes at the expansion tank. The expansion tank has a level in it to indicate the full level, the system senses its a bit low and deploys your yellow low coolant light. Add some coolant and monitor. If it happens again, then you need to look deeper into the problem.

On a dealer estimate, they're going to rape you to the tune of $750-1000 or more for a cooling system refresh, even a minor refresh as described.

[BavarianZHP]

Definitely start a log on all of your fluids.

Keep track of where the coolant bobber is right now. Log that. Then log how much you added to get it between the full and add lines. Date stamp it and monitor. OP return to us on how much you need to add and when was the last time coolant was added.

[kayger12]

Keith, you're getting at the issue I was alluding to in my original post. If its supposed to be a closed system, is it ever "really, truly, actually OK" to need to top off with a cup or two of coolant? Or is just "not that big a problem"? To have a dealer do the pump/thermostat/housing trifecta, what would you expect all in? What about at an indy?

My understanding is that you should never have to top off the coolant unless there is a leak somewhere.

I agree with Dalton that your light was triggered by coolant flowing into the core when you turned on the heat, but the fact remains that the air pocket in the core had to come from somewhere.

I wouldn't be overly concerned about having to replace some coolant here or there, but I would want to find the source of the gradual loss.

Little problems aren't a big deal, but left unresolved (especially with the M54 cooling system) they can turn into big problems.

I would top off and keep an eye on it. I would prioritize replacing your water pump and thermostat within the next 5k.

Above 60k with an original water pump you're on borrowed time, imo.

Bruce's suggestion about the expansion tank cap is a good one as well. And cheap/easy.



Sent from my kick-A Galaxy S3

[2004_blue_zhp]

Radiator cap = Expansion Tank cap or is different?

[BCS_ZHP]

It's the same, only one cap in the entire cooling system, and the only place you can add coolant too.

[kayger12]

Radiator cap = Expansion Tank cap or is different?

Sorry. Meant expansion tank cap. Fixed.

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[CERF04ZHP]

I had the same problem a couple years ago... I would turn my heat on and the light would come on. Turn the heat off, light off. Also coincidentally, the heat was very inconsistent, as in when I had it on 75 or warmer with the fine tune adjustment wheel turned all the way hot, the heat coming into the cabin was luke warm, sometimes cold and rarely hot. Dane suggested I had a problem with my heater core valve: http://www.ecstuning.com/BMW-E46-330i-M54_3.0L/Search/Heater_Core_Valve/ES177235/
Purchased, replaced in about 30 minutes, topped off and bled coolant system, problem solved.

[2004_blue_zhp]

Last question: Everyone has emphasized that you shouldn't open the expansion tank cap when the engine is "hot". Ok, makes sense. I'm i Manhattan in NYC, so my car lives in a garage. When I go get it, the guys need to bring it around, so I have no idea how long they ran the engine and how long it's been sitting still before I get there. I'll need to pull it around the block to put in the coolant. (They are very strict about "no work being done on premises".) What is "cool enough" to open the expansion tank? Engine temp in the blue on the dash? Everything in engine compartment cool to the touch? A certain number of minutes after turning off the ignition? Thanks for your help.

[BCS_ZHP]

Grab the upper radiator hose, it feeds into the expansion tank, if you can squeeze it then the coolant is still cool enough to open the expansion tank. It the hose is too hot to hold and/or you can't squeeze it, don't open that expansion tank until it cools down some.

[nike001]

My understanding is that you should never have to top off the coolant unless there is a leak somewhere.

Not necessarily true. The cooling system is a closed system, but it's not unlikely to top it off every now and then. It's actually a ritual that most techs do at the BMW dealer I work with. When buttoning the car up, they had windshield washer fluid and top off the coolant.

[kayger12]

Not necessarily true. The cooling system is a closed system, but it's not unlikely to top it off every now and then. It's actually a ritual that most techs do at the BMW dealer I work with. When buttoning the car up, they had windshield washer fluid and top off the coolant.

If you have to top it off, it's because you're losing coolant somewhere.

It's a closed, pressurized system. If you don't have a leak, you should not need to top it off.

Are you saying a properly operating system "uses" coolant?

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[2004_blue_zhp]

Ok. Finally got around to topping off the coolant. I added about 1.25 liters of fluid. That got the lower sphere on the floating stick up to the top of where the expansion cap screws on. I.e. "max fill". What do you guys think. Is adding that much coolant cause for concern? For example, does anyone know how much coolant is the difference between "min fill" and "max fill"?

(Brief aside: I added about 0.75 liters of coolant and about 0.5 liters of distilled water. I was alternating one and the other and ended with coolant so wound up with a bit more concentrated than 50:50. I figured it didn't matter given that the whole system is more than 8 liters. No issue with that logic, right?)

[danewilson77]

Most likely you have a leak = cause for concern.

Williamsburg, VA, Droid DNA, Tapatalk

[kayger12]

^ This

The coolant had to go somewhere.

Small coolant loss left undiagnosed often turns into large coolant loss.

If it were me, I'd want to hunt it down.

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[2004_blue_zhp]

Fair enough.

Kayger: I'm in NYC and I see you're in NJ. Can you recommend an independent shop in the vicinity? I agree this isn't a good issue to ignore. That said everyone I know who has gone to the NYC dealership for service has come away wishing they hadn't. (No space or experience to DIY this on my end.)

[kayger12]

List of what are supposed to be reputable indy shops here http://www.bimrs.org/2008MapPage.html

Also have heard good things about Bimmer Clinic in Elizabeth. http://bimmerclinic.com/home/

[LivesNearCostco]

If that is true then I feel better about my car loosing a small amount of coolant. Though as Kayger said, it's going somewhere...

Not necessarily true. The cooling system is a closed system, but it's not unlikely to top it off every now and then. It's actually a ritual that most techs do at the BMW dealer I work with. When buttoning the car up, they had windshield washer fluid and top off the coolant.

[2004_blue_zhp]

To tie off a loose end. Topped off coolant 2x more. Each time needed way less than previous. Now been 2k more miles with 0 decrease in coolant level. Guessing system was incorrectly bled last time Indy refilled it and it took a few top offs to deal with air bubbles working their way out. Replaced expansion tank cap ($30 at dealer) as insurance against leaky o rings there.

[LivesNearCostco]

I was sure my coolant loss was coming from where ET meets mounting plate, so bought new ET at dealer ($130 after CCA discount and tax), put it in last Friday. Drive 450 miles + 160 minutes on track over the weekend, zero leaks! But yesterday my coolant light came on again and found coolant on undertray, ET nearly empty.

New theory: I didn't put on the ET cap tight enough most of the time. Yesterday there were fresh traces of dried coolant on the top and sides of the brand new ET. If the leak were only from the bottom/plate, can't see how it would get up onto the sides of the ET. It must be the cap (I tells myself). Either it's a failed cap, wasn't on tight. I put it on very tight last Friday but opened it Monday or Tuesday to check on the coolant level. Still have my old cap in the trunk just in case. The good news is now I'm sure I do NOT have a headgasket leak and my coolant loss before was not disappearing into the oil (confirmed with multiple UOAs). It was just coming out of the ET somewhere...

[LivesNearCostco]

I'm embarrassed to say that at least some of my old coolant leak and all the leaking after putting in the new BMW ET was from not tightening the ET cap enough. I figured it just had to be lightly snug because the two small O-rings on the ET plug would blog the opening. But it seems the bigger rectangular profile O-ring at the top has to seal tight against the inside of the opening or it leaks when hot.

[BCS_ZHP]

An honest tech once told me one of the weaker links in our e46 system is the EP cap, dealers use it to sell you a cooling system refresh. His advice was if the coolant level sensor in the EP, "the dark red thermometer", was dark red then just replace the cap. However if its light red or pink or even white, refresh the whole cooling system.

[LivesNearCostco]

Yes but I can't even blame a failed ET cap! It it was "user error." *Maybe* the Meyele ET wasn't sitting properly on the mounting plate, not sure.

And now I have 3 ETs--two genuine BMW ones (one new, one with 75K miles) and one Myele ET with 20K miles.

[echo46]

I'm skeptical of the quality of Meyele products. I had a fit issue with a Meyele ET and quickly went back to a BMW ET for a perfect fit.