So I made a discovery today when I was cleaning up my engine and it answers the question that many have asked in the past.

While cleaning today I noticed a very small drop of coolant just below my coolant reservoir, so I started looking around the reservoir and the hoses to find out where the leak was coming from. I couldn't find a leak anwywhere and everything I touched was dry. So I thought maybe the coolant level sensor might be leaking around the circlip, again everything was dry and clean. I decided to pull the wire off and check the sensor and all of a sudden coolant started pouring out of the wiring harness!! I grabbed a rag and tipped over the harness and watched a ton of coolant flow out. I couldn't believe it. This explained why I had a slight coolant drop without any visible leaks. I spoke to my mechanic and he explained that the sensor typically fails from the inside where the electrical connection is made which explains how this happened.

So anyone that has mysterious coolant loss, check your level sensor first, could be dripping down the wire into the insulation.

Hope this helps someone.

__________________
Afshin

Current:
02 C32 AMG

Previous:
92 500E
84 190E 2.3 5 Spd