View Full Version : 06 BMW 530i Brown GOO found in my coolant- NEED HELP!

07-16-2012, 04:12 PM
Hello, I'm a new member and love the advice given on this site. I NEED HELP on figuring where this goo is coming from. Here is the scenario!

Car pop up over heat warning so we STOP IMMEDIATELY and tow the car home to prevent any further damage. Open the coolant reserve tank and found this muddy mustard brown fluid mixed in. Got some advice from a friend that the radiator is busted which end up to be true.

Took apart the radiator to find out leaked from the bottom. If I replace this radiator and flush out the system will this solve this issue or would that "GOO" come back to the new radiator.

Check all 6 cylinder compression and it stayed consistent around 215 lbs. Do I just replace the ENTIRE COOLANT SYSTEM which includes: thermostats, transmission fluid cooler, waterpump, radiator... was reading that the mixture could be from the transmission fluid mixed in since Steering wheel fluid is full and oil is in good level. PLEASE HELP!

**Debating to either fix it to sell it or sell it as is. The hard part is coming up with the extra cash to pay for this major repair due to some bad luck incident happening within the last 2 months, bad timing!!!**

2006 BMW 530i sport package 120,000 miles. Mid year production.

07-16-2012, 04:51 PM
, that "goo" stuff is not what you want to see in the radiator. From that picture, it looks like engine oil is mixed with coolant. bad bad news my friend. it looks like the head gasket is shot. the car overheated bad.
a new or re-surfaced head might be needed.
do you see any water or coolant on the oil dipstick?

07-16-2012, 05:09 PM
I concur. When was the last time you had the coolant flushed, and have you ignored any overheat warnings before because there should have been a
warning prior to the engine running too hot (especially since there is no temp gauge).

07-16-2012, 05:18 PM
I6 with 120K.

It was due for a coolant system overhaul; about 20K miles ago.

07-17-2012, 01:58 PM
Its sold now but was told transmission fluid got mixed in which caused that build up. The whole coolant system will need to be replaced obviously. I'm assuming the new owner will replace that and will get it in working order.