Coolant Loss?
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Coolant Loss?
Hey Guys,
I was hoping you might be able to offer up some insight. I own a ‘95 C36 w/ close to 145k. I’ve owned the car for nearly 8yrs now and bought it when it had 101k. The two major parts I had to replace were the water pump and upper harness. I absolutely love the car and refuse to sell it! It rarely gets driven, but I make an effort to take it out on a spirited drive once or twice a week. All the records were transferred to me when I acquired the car. One of these invoices confirms the head gasket was replaced at the MB dealership when the car had 49k miles prior to the mfg. warranty expiring.
In the first 2-3 yrs of ownership I noticed the car would exceed the 100c mark before the fan would kick-on and knock it back down to about 95c. This was a typical scenario in humid weather or sitting in traffic. After about 4 yrs I decided to replace the fan clutch and fan itself which made a huge difference in dropping the temp when the car started moving. Also, the coolant resovoir cap. New thermostat too in addition to a coolant flush with the updated MB coolant. The car still rises up to the 102c range before the fan initiates on a humid day when idiling in stop and go traffic. Till this day though I get a bit of coolant loss on a very humid day when idling for a period or sitting in traffic. A tech pressure tested the car 3 yrs ago and confirmed there were no issues.
I’m curious to know if this is common on the M104 (C36). I generally add a bit of coolant 2-4 times per year. There is no contamination in the coolant resovoir and the oil looks clean. My car requires a small amount of top off oil every 3.5-4K miles. That’s about the extent of it. Any insight would be appreciated!
Cheers,
-Rob
I was hoping you might be able to offer up some insight. I own a ‘95 C36 w/ close to 145k. I’ve owned the car for nearly 8yrs now and bought it when it had 101k. The two major parts I had to replace were the water pump and upper harness. I absolutely love the car and refuse to sell it! It rarely gets driven, but I make an effort to take it out on a spirited drive once or twice a week. All the records were transferred to me when I acquired the car. One of these invoices confirms the head gasket was replaced at the MB dealership when the car had 49k miles prior to the mfg. warranty expiring.
In the first 2-3 yrs of ownership I noticed the car would exceed the 100c mark before the fan would kick-on and knock it back down to about 95c. This was a typical scenario in humid weather or sitting in traffic. After about 4 yrs I decided to replace the fan clutch and fan itself which made a huge difference in dropping the temp when the car started moving. Also, the coolant resovoir cap. New thermostat too in addition to a coolant flush with the updated MB coolant. The car still rises up to the 102c range before the fan initiates on a humid day when idiling in stop and go traffic. Till this day though I get a bit of coolant loss on a very humid day when idling for a period or sitting in traffic. A tech pressure tested the car 3 yrs ago and confirmed there were no issues.
I’m curious to know if this is common on the M104 (C36). I generally add a bit of coolant 2-4 times per year. There is no contamination in the coolant resovoir and the oil looks clean. My car requires a small amount of top off oil every 3.5-4K miles. That’s about the extent of it. Any insight would be appreciated!
Cheers,
-Rob
Last edited by RPB; Oct 3, 2017 at 07:36 PM.
Thread Starter
Super Member
Joined: Sep 2007
Posts: 754
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Thanks for your response, can you please elaborate for me? My current fan turns on around 102c. Is this not the correct operation, if my memory serves me correct the first stage initiates a little over 100c and then another stage around 110ish which I have luckily never experienced.
I would assume this is the function of the "fan sensor switch".
Thanks!
-Rob
I would assume this is the function of the "fan sensor switch".
Thanks!
-Rob
