Coolant problem on 2000 540i - BMW Forum

bccwu · 12-15-2003, 02:28 AM

Hi, I would like to get some opinions on this small issue. Recently the LCD indicator started giving me the warning about "checking coolant level". So I checked and it's almost empy. So I called the service dept. of the local BMW dealership. The guy told me I need to bring it in and do a total coolant flush. This car has really really low mileage : about 20K KM or 13K Miles. I hardly drove it for the last 10 months. My question is : Can I simply do a coolant refill or the guy just wanted my money?

Thanks, Bill

SoonerE39 · 12-15-2003, 04:23 AM

Normally a radiator flush is done around 60,000 miles. I don't see a problem with just filling it and avoiding the flush with your mileage that low.

Chooch · 12-15-2003, 04:45 AM

fill it and do a pressure test of the coolant system .... you can get the kits, i think, at auto supply stores ... you may have a busted hose or worse a crack in the engine block ... i really don't think it's normal to be that low on coolant ... maybe the thermo is shot and the coolant is boiling over ....

EXtech · 12-15-2003, 01:30 PM

don't get all freaked out about a cracked block or anything. Fill the system and then pressure test it. Don't do a flush, you don't need it yet. There used to be a radiator cap recall on alot of the cars do to coolant loss from improper sealing. I would go through a pressure testing of the system and determine if there are any leaks. If the car has any warranty, then let the dealer do it and make sure they do an extended test on it where they leave the system pressurized for at least 20 minutes ( and not completely cold). From the sounds of it, I would take it to a different place than the one that told you to flush the system. It will be very expensive to go buy the tester itself because after you spend $60-100 or more for the tester, then you have to buy a special adapter for the beemers and those cost 20-30 bucks. After you've covered the basics, then start focusing on more complex issues.

bccwu · 12-16-2003, 01:33 AM

Thanks for these helpful advices. Yesterday after work, after reading your advices, I went to the dealership trying to get some genuine BMW coolant, but the guy told me it was just generic aluminum compatible antifreeze they sold. So I bought some from a local Canadian Tire (like Kmart in the States) instead. I tested the colour of the remaining coolant in my car and it was very green so there was no dirt in it.

I then mixed 2 L (1/2 GAL) of the bottled coolant 50:50 with some spring water (the purest I could get from a grocery store). I proceeded to fill it up in the car. The coolant indicator popped up after less than 300ML (0.08 Gal) or so of the mixture added! I put the cap back and start the engine. The warning disappeared!

questions :
1) Could I have a faulty coolant level sensor?
2) can I store away the remaining 1/2 GAL non-mixed coolant and the already mixed (with water) coolant for future use? I put them in the unheated garage, but it's like -15C (5 F) outside)
3) if I proceed to do a pressure test, can I just go to any hardware store and pick up a pressure test kit? Where can I get the special adoptor the last poster suggsted?

Thanks again, Bill

EXtech · 12-16-2003, 03:44 AM

It doesn't take much to set off the low coolant sensor in these cars. If the level dropped below where you could see it then it was probably low enough to trip the light. If it was only that low, I would suspect that you've got a huge leak or anything but if you want to still test the system then you can find the adapter at any major tool supplier like Snap On, MAC Tools, Matco Tools, Stahl Wille, Cornwell. I know a Stahl Wille toolman here in Texas who is the best guy in the world. If you want, I can put you in touch with him. He has awesome prices and usually will work deals not to mention he has access to any tool that you want. The good thing about Stahl Wille is that they specialize in German auto maker tools (ie. for BMW, Mercedes....). PM me if you are interested. Hell, if anyone else is interested then PM me also.

EXtech · 12-16-2003, 03:49 AM

..the more that I think about it, if there is something that is wanted by the masses then he would surely make a group discount. He has pressure testers to brake bleeders to specialty wrenches to service indicator reset tools.. everything you can't find anywhere else.

CosmosBlack · 12-16-2003, 05:51 AM

bccwu,

My advice from personal experience with two 540i radiators, is to check around the plastic "neck" area on top right (when you're standing in front of the car facing radiator) of the radiator. That is a common problem with fine hair-line cracks, which you wouldn't even notice normally. Also, on the 2000 540's, the upper assembly hoses for the radiator, where it goes into the engine, they need to be replaced. It's in the service bulletin. If you check them out and see greenish deposits around the joints, that's one of the possible causes of a leak. The updated replacement is a simpler setup and has less joints.

Good luck!