mani198

Hi everyone I have a m156 engine Amg s63. My father was driving it the other day and told me he seen the temp needle reach the 120 mark at which point he stopped driving and let the engine cool. He made his long journey back home and the temp stayed stable at 80. He tells me it happens when the cars sitting in traffic. Now I opened the bonnet today amongst the rain we have been having and noticed the radiator pipe sought of collapsed on itself ie there was a vacuum built up in it. This pipe is the one that connects to the rad mid way. Once the car reached temp the fan kicked in. Well I thought to myself the fan is working. I revved the car at 2000rpm and held it there for a minute or so. The fan kicked in at what seemed to be full rpm I've never heard it spin so fast something was telling it the temp was high but on the gauge it was reading a little higher than 80. Now I opened the coolant reservoir tank to find the coolant wasn't actually that hot! What's going on? Is the pump playing up. As I'm reading into this I've found there may b an electronic auxiliary pump as well what's this for. I'm would class myself as an intermediate diy mechanic lol. Anyone got suggestions or has this happened to you. I initially though fan module but fan runs.

triniexr

I would think that is a thermostat issue.

mani198

I was thinking the same thing. I've taken it to an independent garage and his had it connected to the computer. He tells me the fan doesn't kick in more than 30 /40 %. So he want to replace the fan the temp sender and the thermostat. Doesn't make sense as I've heard the fan working at full rpm! Which sounded like a turbine. Would this fan have a control module like the rest of them? Surely if the fan motor is getting voltage and spinning it's nothing to do with the motor. It's something to do with the controller of this 850w + motor or the temp sender but his doesn't explain the vacuum in the pipe. 😬