BMW coolant question

[munciedr]

I am a new owner of a 1995 525i and recently noticed a puddle of coolant under the car. It is not a huge puddle and it only occurs occasionally. Also, I noticed that the coolant is blue in color and, as a first time bimmer owner, that is new to me. I am familiar with the green and red coolants, but not blue. My questions are this:

1. Is this blue coolant a special coolant that I need to use in the car and if so, can I get it anywhere other than from a dealership? Can one use the green or red types of coolant in this car?

2. Any ideas about the occasional coolant leak? The car has not had an overheating issue while I have had it and the leak is not very large and I have not been able to see where the leak is coming from by my first quick looks under the car. I have not done an exhaustive search, but as a guy who has worked on plenty of american cars (I am not new to car work - just working on BMWs), I am comfortable in an engine bay. I made a quick look underneath and could not readily see any leak location and plan to put the car up on ramps and look more closely, but just thought Iwould ask these questions here in case there first.

Thanks in advance for any help!

[zmuff]

The blue coolant is genuine BMW coolant available only from the dealer. There are lots of stories bouncing around about green and orange being 'bad' coolants, but there are just as many stories of folks using them for years with no issues. If you have blue already, stick with it.

As far as your leak, just keep looking around. The radiator necks are prone to cracking, as are all the plastic pieces in the cooling system. Check all of the hose connections with the engine cold using a mirror and look for a drop of coolant hanging under the fitting. Good luck.

Mike E.
Yorktown VA

[munciedr]

Thanks Mike!

I am guessing that you can't mix the blue with other colors, so I will just stay with that one for now and get it from the dealer. About the leak, I was looking around a bit and it looks like the leak might be coming from around the water pump shaft. Since the leak/puddle has only showed up occasionally it has been hard to diagnose, but it looks like there has been some coolant flung around the area of the water pump pulley. Do these tend to leak around that shaft? I haven't been able to find a leak anywhere else and the plastic necks on the radiator, etc., look OK for now. Also, in looking through some past posts on this forum, it sounded like the water pumps on these cars are not replaced completely - but the internal impeller (which was plastic from the factory) are replaced. Am I reading that correctly or have I mis-read something? Again, thanks for your help and any additional info is greatly appreciated!

[zmuff]

The m50 engine is not my strong point but I'll see if I can help. Definitely don't mix coolants...you're okay there. More often than not, the impeller starts slipping on the shaft and doesn't cool as well, or the impeller degrades and just explodes...plastic everywhere. But any water pump can start leaking past the front seal. If yours is still the original, it should be replaced when you have a chance. Here's a link to BMA parts, best prices around...free shipping over $50.00.

BMA Auto Parts

Sorry for this HUGE pic! It's all I could get.

[uscharalph]

You can't mix coolants. They don't mix very well and can cause problems in your radiator. You are going to have to either go to the dealer (Expensive $32 / gallon) or try www.bmaparts.com ($19.00 / gallon).