ravi6561
New Member
Hi,
Apologies if this has been resolved in the past, or if this has been posted in the wrong place.
I have a 2007 CL500 C216 with 86k miles on it, and the fan runs at a very high speed once the car is up to operating temperature. It is super loud when it runs this fast. It may slow down here and there, but once the coolant temp is at 82ish C, it's on pretty much all the time and is loud. A/C still works fine. The temperature on the dash has never gone past about 85C.
So far, I have changed the thermostat, and have flushed the coolant twice, and am wondering what to do next. I'm thinking water pump. There seems to forever be air in the system, although there are no leaks I can see.
When I have disconnected the fan momentarily with it running at high speed, to see how hot the radiator is, immediately the yellow coolant symbol appears on the speedo, and the radiator is usually warm, but not hot. Same goes for the expansion tank, its fairly warm, but not 80C hot.
I noticed today that when reinstalling the air filter housing, as I was tapping it in to place with my hand, the fan turned on for a few seconds and stopped. I then tapped the ECU (bosch me 9.7), and again the fan spun up then stopped even though the engine was off. This now makes me wonder if the ECU is bad. I also have been getting a P2088 code, which relates to the cam adjuster magnet, so i replaced all 4 cam adjusters, and still get the code reappear on a daily basis. I can't see any evidence of oil having leaked in to the wiring harness from the old cam adjusters, nor do I think it is premature wear on the idler gear which i know can happen on the M273 engine
My thinking is that if it was the Ecu, then why does the fan at full speed only happen after the car has gotten to operating temperature, and not before. Having the A/C on or off makes no difference. But on the flip side, if it was the Ecu, it might explain the P2088 code.
And advice or suggestions would be very much welcome. Thanks
EDIT: I should add I've used icarsoft MB II, and the only odd things I noticed was the intake air temperature was a found 50C, unplugging the MAF sensor made no difference to the fan. Also, the transmission fluid was always around 55C, so it wasn't that I presume. The request for engine fan never went about 25% at any point, nor does it change when the fan spins up or spins down. Car has been maintained well over the 4 years I've had it, oil change every 5k miles.
Apologies if this has been resolved in the past, or if this has been posted in the wrong place.
I have a 2007 CL500 C216 with 86k miles on it, and the fan runs at a very high speed once the car is up to operating temperature. It is super loud when it runs this fast. It may slow down here and there, but once the coolant temp is at 82ish C, it's on pretty much all the time and is loud. A/C still works fine. The temperature on the dash has never gone past about 85C.
So far, I have changed the thermostat, and have flushed the coolant twice, and am wondering what to do next. I'm thinking water pump. There seems to forever be air in the system, although there are no leaks I can see.
When I have disconnected the fan momentarily with it running at high speed, to see how hot the radiator is, immediately the yellow coolant symbol appears on the speedo, and the radiator is usually warm, but not hot. Same goes for the expansion tank, its fairly warm, but not 80C hot.
I noticed today that when reinstalling the air filter housing, as I was tapping it in to place with my hand, the fan turned on for a few seconds and stopped. I then tapped the ECU (bosch me 9.7), and again the fan spun up then stopped even though the engine was off. This now makes me wonder if the ECU is bad. I also have been getting a P2088 code, which relates to the cam adjuster magnet, so i replaced all 4 cam adjusters, and still get the code reappear on a daily basis. I can't see any evidence of oil having leaked in to the wiring harness from the old cam adjusters, nor do I think it is premature wear on the idler gear which i know can happen on the M273 engine
My thinking is that if it was the Ecu, then why does the fan at full speed only happen after the car has gotten to operating temperature, and not before. Having the A/C on or off makes no difference. But on the flip side, if it was the Ecu, it might explain the P2088 code.
And advice or suggestions would be very much welcome. Thanks
EDIT: I should add I've used icarsoft MB II, and the only odd things I noticed was the intake air temperature was a found 50C, unplugging the MAF sensor made no difference to the fan. Also, the transmission fluid was always around 55C, so it wasn't that I presume. The request for engine fan never went about 25% at any point, nor does it change when the fan spins up or spins down. Car has been maintained well over the 4 years I've had it, oil change every 5k miles.
Last edited: