Adding Coolant

[Snakepit]

I've had my 540 for a year now and put close to 5k miles on it. I've always checked the coolant since I bought the car but lately the "coolant level owner's manual" message comes on almost everyday now.

The coolant seems to have dipped a little bit and I was thinking of adding more. However, I don't know what brand is in there right now and I wasn't sure if its ok to mix brands of coolant. And how full should it be?

I tried searching but all I could find was instructions on how to flush the system.

Little help?

[e34Croak]

May need a water pump if it is losing coolant check around that area before just adding more coolant to see if you can find a leak. There is a thread somewhere about phosphate levels and all that stuff concerning what type of coolant to use. IMO it's not a huge deal to run your Wal-Mart type of anti-freeze (not sure though).

[bradhouser]

I've had my 540 for a year now and put close to 5k miles on it. I've always checked the coolant since I bought the car but lately the "coolant level owner's manual" message comes on almost everyday now.

The coolant seems to have dipped a little bit and I was thinking of adding more. However, I don't know what brand is in there right now and I wasn't sure if its ok to mix brands of coolant. And how full should it be?

I tried searching but all I could find was instructions on how to flush the system.

Little help?

It should be almost to the top of the filler neck, so none spills out when you put the cap back on.

Looking for leaks:
Check for drips under the car after parking over night. Check for smell of coolant in the AC. Check for loose hose clamps. You can also buy flourescent UV dye and a black light to check for slow leaks.

(I had what my mechanic said was a heater core leak. These are a PITA and $$$ to repair, so I bypassed the heater for one season. After closer inspection, it turned out the heater valve was broken, so I replaced that, and things are much better. I still get the occasional COOLANT LOW message, but not like I did before. I can live with it now, so I have heat again. I always have a gallon of coolant in the trunk.)

Compatible coolant:
Of course you have the expensive stuff at the dealer. Or you can get Xerex G05 at Kragen and other places. It is one of the only aftermarket coolants that is OK for BMWs. Check the label, some are premixed with water. I pay about $14 for the unmixed coolant.

[Snakepit]

No drips under the car. And the temp gauge stays solid at the center line. So is it safe to get Zerex and just add that to whatever is in the reservoir right now just to fill it back up?

Thanks for the help.

[jimoreno]

If you look at the front translucent wall of the expansion tank, there is a mark for the "Max Cold" level with an arrow molded in the plastic. If you have blue stuff it's the original BMW stuff. I get it at the dealer for $16 a gallon undiluted which is the same price that I paid for the Xerex around here. Get a gallon of distilled water to mix at 50% strength. Just in case, take a look at this post (http://www.bimmerboard.com/forums/posts/264840)for an e38 but is the same engine. It shows the valley pan gasket replacement and typical leak points.

[Shuasha]

If your coolant isn't actually low, it could just be the coolant level sensor. They go bad all the time and are pretty cheap and easy to replace.

[Snakepit]

If you look at the front translucent wall of the expansion tank, there is a mark for the "Max Cold" level with an arrow molded in the plastic. If you have blue stuff it's the original BMW stuff. I get it at the dealer for $16 a gallon undiluted which is the same price that I paid for the Xerex around here. Get a gallon of distilled water to mix at 50% strength. Just in case, take a look at this post (http://www.bimmerboard.com/forums/posts/264840)for an e38 but is the same engine. It shows the valley pan gasket replacement and typical leak points.

Checked the translucent wall and the coolant is about half an inch below the Max Cold level. I'm thinking just adding coolant should do the trick? But I stopped at a local Kragen to get some Zerex but its pink instead of the bright green that's in the reservoir right now. Is it safe to mix those two? Or should I pick another brand (Prestone) that says "ok to mix with other colors" on the label?

[E34Kevin]

if its dipped "a little bit" why not just some water??

[Snakepit]

if its dipped "a little bit" why not just some water??

Is it safe to top it off with just water?

[queens]

Did you check if you have coolant in your oil?

Get NGR+ waterless coolant from BavAuto or get BMW anti-freeze and mix it with distilled water 50/50 and top it off + bleed it. I would not recommended using any gas stop coolant/wall mart brand in your car.

If it's hot out you can just run on distilled water without any problems.