Coolant light came on

[HokieZHP]

So driving home tonight my coolant light came on then went back off...kinda worried. Is this a failing cooling system symptom?


Sent from my iPhone using Tapatalk

[Hornung418]

Nah. Be worried if it comes on and doesn't go off 30 seconds after start-up. Was your heater on? It could have filled up the core and you had some air in the system draining the expansion tank :dunno

[HokieZHP]

It was on for the end of thedrive home. (1-2 mins) then went off when I parked and went to take a pic. I turned the heat on but it wasn't warm yet.

Btw my cooling system hasn't been done to my knowledge.


Sent from my iPhone using Tapatalk

[Hornung418]

Check your expansion tank for a visible sticker and it should have the date listed when the part was manufactured. If it's more than 3 years old, I'd be scared.

[HokieZHP]

Ok. My guess is that it's stock.

Where is the expansion tank?


Sent from my iPhone using Tapatalk

[Hornung418]

Come on...it's the thing that connects to your radiator and upper radiator hose...the thing with the cap on it...the thing next to your GruppeM...

[HokieZHP]

Alright haha yeah I've never read into the cooling systems for these cars before and just don't know a ton about the specifics of them. I'll check it tomorrow though.


Sent from my iPhone using Tapatalk

[JKO_ZHP]

The first time this happened to me in my 325Ci, I just mixed BMW coolant with distilled water (50/50) and added some in.
Light never came back on since then.
(Until it got T-boned of course but then all lights were on) :facepalm

[danewilson77]

Ok. My guess is that it's stock.

Where is the expansion tank?


Sent from my iPhone using Tapatalk

http://www.zhpmafia.com/forums/showthread.php?t=588

Sent from Williamsburg, VA USA

[328ioc]

If the light is on add one cup or less of water. Not a full cup such as a solo but the actual measure of a cup.

I have found out that not filling the system all the way but instead filling it to just over the min line aka when the light comes on goes a long way in keeping the system from going all kamikaze because it keeps the pressure in check.

Sent from my DROID RAZR using Tapatalk 2

[HokieZHP]

Not a full cup such as a solo but the actual measure of a cup.


Sent from my DROID RAZR using Tapatalk 2

Thanks for the advice and I appreciate you speaking in terms a college kid like myself can understand with the solo cup reference haha.

I just got out of my dynamics class and will I check out the expansion tank and level shortly.




Sent from my iPhone using Tapatalk

[3ZHP]

Happened to me a few years ago and turned out to be a bad water pump. The thread attached shows diagnosis and fix.

Good luck, and let me know if you need any additional help.

-3ZHPGuy-
http://www.zhpmafia.com/forums/showthread.php?524-BMW-E46-Water-Pump-Failure-Diagnosis-and-Replacement&highlight=water+pump

[HokieZHP]

Thanks.

I just looked at it and didn't see any noticeable cracks or leaks

[328ioc]

Thanks for the advice and I appreciate you speaking in terms a college kid like myself can understand with the solo cup reference haha.

I just got out of my dynamics class and will I check out the expansion tank and level shortly.




Sent from my iPhone using Tapatalk


Us college kids have our own language don't we?

Plus I didn't want you dumping a full 12oz in that would be way to much lol.

[Hornung418]

If it's a hairline crack you won't see it until you remove it. Look for streaks of dried coolant on the sides of the ET and it should point you in the right direction. I didn't see any coolant from underneath your car on Saturday So I doubt it's coming from the front of the block. It very well could have been a fluke, they happen from time to time. But if you find the date on the ET matches the Build date, you're long overdue for an overhaul!

[HokieZHP]

So.....looked at the date on my expansion tank while I was checking out my front suspension (see clunking sound thread) and the date was 6/2003 haha so it's very very old.

[BCS_ZHP]

Chris,
I was losing coolant 2 months ago on GiGi's car, had a thread around here somewhere. I replaced just the expansion tank cap and its not leaking anymore. I know my wife's coolant systems is low mileage (42K) but its aged (2004) so I'm planning to replace it soon. But the $10 new cap bought me some more time as I'm no longer losing coolant.

Wish I had seen this earlier, I have a spare brand new cap here and Preston left this afternoon to head back your way. If getting to a dealer is a problem for you, PM me your address and I'll ship the cap out tomorrow. Basically, comparing original to new, you'll notice a big difference in the o-rings on the cap itself -- yours have probably flattened out over time whereas a new one has full/plump o-rings. Now if you're losing a crap load of coolant then its likely the water pump and its weep hole. Just a little and its probably just this cap.

[HokieZHP]

It must just be a small amount if any cause I looked at the bottom of the tank and there is no residue or anything and none on top either. The light hasn't come one since even with the heat going. I'm trying to decide if it was just a glitch or what.

[nike001]

Woah. Why does everyone jump to such bold conclusions here?


OP, the light came on because you were already somewhat low on coolant. What happened was the coolant flowing to your heater core was just enough to trip the light. It's a common thing, and the fix is to just add water or coolant. That's it. It had nothing to so with cooling system components other than a potential leak

[BCS_ZHP]

Chris,
The cap is only $10, replace that and I think you'll solve the problem satisfied until you can budget it a cooling system refresh. I too could not find an evidence of coolant leak, maybe a tiny bit around the neck of the expansion tank but only found that in retrospect after I replaced the expansion tank cap.
Bruce

[HokieZHP]

Alright. Well I think I'm going home tuesday so I can 1.) get a new ID since I lost mine, 2.) have my mechanic check out my suspension and get an alignment and 3.) play some golf and catch up with my mom. So I can get a new cap while I'm down there but if I can't then I'll shoot you a PM bruce and buy that cap off of you.

Thanks!

[danewilson77]

Alright. Well I think I'm going home tuesday so I can 1.) get a new ID since I lost mine, 2.) have my mechanic check out my suspension and get an alignment and 3.) play some golf and catch up with my mom. So I can get a new cap while I'm down there but if I can't then I'll shoot you a PM bruce and buy that cap off of you.

Thanks!

Have you found evidence of a leak? Is/was coolant level low?

Sent from Williamsburg, VA USA

[danewilson77]

Thanks.

I just looked at it and didn't see any noticeable cracks or leaks

Copy. Answered my own question.

Sent from Williamsburg, VA USA

[HokieZHP]

I haven't checked the level yet. But I didn't see any evidence of a leak when I was just under the car

[danewilson77]

I haven't checked the level yet. But I didn't see any evidence of a leak when I was just under the car

This happened 4 days ago?

Sent from Williamsburg, VA USA

[HokieZHP]

The light came on a few days ago but then went off and hasn't come back on since.

I was just under the car an hour ago though.

[BCS_ZHP]

Very similar to my situation, try the cap first.

[danewilson77]

I wouldn't try shit if there's no visible leak and level is good, and light has stayed off.

Sent from Williamsburg, VA USA

[BCS_ZHP]

Dane, no visible leak with mine either but coolant was obviously going somewhere. O-ring gaskets on the cap must have been depressed enough to let a little vapor release each heat up/cool down cycle, but the simple $10 cap fixed it.

[danewilson77]

Dane, no visible leak with mine either but coolant was obviously going somewhere. O-ring gaskets on the cap must have been depressed enough to let a little vapor release each heat up/cool down cycle, but the simple $10 cap fixed it.

Ok. Guys are finally using heaters this time of year, and we get a lot of these indications of the light blipping on and off (as Nike suggested), when heater core takes up some coolant. Cap is very good preventative maintenance. If it were me, I would probably add a couple of cups of 50/50 (not to overfill) and watch it for a while.

If it is the cap o-rings, it'll come back, but won't blow or anything.

Sent from Williamsburg, VA USA