C43 Cooling Fan Issue

[sgregory124]

As per Germgh0st, 29mpg is about right. I've never seen above 30, 32 mpg and thats driving in Eco mode mainly motorway with very light throttle movement when we had the fuel shortage.

After all, it is a 3 litre twin turbo, tuned for performance so I wonldn't expect high mpg figures.

Personally I am super happy with the mpg figures I get as I actually expected a lot less when I bought this car.

If it is economy you are after, forget about buying AMG engined cars. They are primarily designed for performance, and not enconomy. Getting heavy on the right foot on occasion is irresistable as that is what they are about. and that costs petrol

Quite bizarre this - my C63S will do 33mpg on a motorway run and regularly reaches 28/29 on A's and B's (assuming i'm adhering to speed limits in all cases). Got to be down to individual driving styles more than the engine surely?

 

[f17ant]

Quite bizarre this - my C63S will do 33mpg on a motorway run and regularly reaches 28/29 on A's and B's (assuming i'm adhering to speed limits in all cases). Got to be down to individual driving styles more than the engine surely?

Same I can get 33mpg on a long motorway run and 27-29 on empty B, but London roads 20 or less

 

[sgregory124]

Same I can get 33mpg on a long motorway run and 27-29 on empty B, but London roads 20 or less

20? I've seen 9 mpg on a cold morning commute into Nottingham

 

[Germgh0st]

It’s juts strange that I was getting upto 39mpg which was great! Good to know people are getting the around 29mpg, I knew what I was buying, just strange that I was averaging 39mpg in eco mode which gave me a false sense of economy!!!

It’s not the end of the world to be fair but will keep you guys posted on how things go.

The MPG figure on the dash is a calculated figure based on your driving style etc, worked out by the ECU. You'd be better off keeping a paper record to measure it properly than relying on what the ECU tells you.

 

[f17ant]

Quite bizarre this - my C63S will do 33mpg on a motorway run and regularly reaches 28/29 on A's and B's (assuming i'm adhering to speed limits in all cases). Got to be down to individual driving styles more than the engine surely?

Same I can get 33mpg on a long motorway run and 27-29 on empty B, but London roads 20 or less

20? I've seen 9 mpg on a cold morning commute into Nottingham

granny driving!

 

[classiccarzone]

Might not relate to all of the OP problems but if you were using the A/C, the A/C module will keep the fan running for a time after the engine switches off.
If the A/C module fails (happens often when a discharged battery is changed) the fan will switch on within 30 seconds and will stay on until the ignition is switched off.

 

[Barnowl1]

Mine is a 2020 C 43 with 10 k on the clock. I’ve noticed that the cooling fans stays on for a few minutes after the engine is turned off. even after just a short ( say 3 mile journey) I also assumed it’s normal, but I’ll ask at the next service as it in the Approved scheme.

 

[RobMea]

Hi, has anyone got to the bottom of the fan issue?

After having my 2018 68 plate for around 4 months the fan has started staying on after every journey. Also my fuel economy has dropped noticeably since the issue started.

Wondering if anyone knows what causes this?

Thanks

 

[RobMea]

Mine is a 2020 C 43 with 10 k on the clock. I’ve noticed that the cooling fans stays on for a few minutes after the engine is turned off. even after just a short ( say 3 mile journey) I also assumed it’s normal, but I’ll ask at the next service as it in the Approved scheme.

Did you get to the bottom of this when your car went in for a service Barnowl1?

Any feedback would be appreciated!

 

[RobMea]

Did this ever get fixed , as I’ve noticed mine has done this today and yesterday ? Wondering whether to contact the dealer

Hi Mike, did you get to the bottom of this. Mine has been in to the dealer today because of this but they said no issue. Just doesn’t seem right…

 

[Mike9999]

Hi Mike, did you get to the bottom of this. Mine has been in to the dealer today because of this but they said no issue. Just doesn’t seem right…

no - still happens - weirdly seems to happen only in winter - in summer its ok - sam ething occasionally happens on the wifes M4 as well so have put it down to a performance car "feature"

 

[RobMea]

no - still happens - weirdly seems to happen only in winter - in summer its ok - sam ething occasionally happens on the wifes M4 as well so have put it down to a performance car "feature"

Thanks for the reply… Do you notice a drop in mpg when it happens?

 

[fatzwithaz]

Just joined this as my 2020 C63 Cab with G/OPF had this issue last year and is now back.

I experience the car hanging in lower gears, hence 20% more fuel consumption, then on engine turn off the cooling fans always run on.

Last year the issue was solved by a "hard" gearbox reset at my local dealer under warranty. A soft reset failed to cure it. There were no error codes (allegedly) so were unable to comment on why it happened.

Why would the cooling fans come on with a gearbox issue?!

A work colleague has suggested it may be to do with the O/GPF trying to undergo a regeneration cycle but unable to complete due to my short journey to work (6 miles). He has the same issue on his diesel dpf car, except the gearbox hanging, as his is a manual (could my car be hanging in lower gears to increase the temp to aid regen?). His issue is solved by a long, hard drive. I'm going to se if this sorts mine this evening.

Comments welcome?

 

[TS99]

Just joined this as my 2020 C63 Cab with G/OPF had this issue last year and is now back.

I experience the car hanging in lower gears, hence 20% more fuel consumption, then on engine turn off the cooling fans always run on.

Last year the issue was solved by a "hard" gearbox reset at my local dealer under warranty. A soft reset failed to cure it. There were no error codes (allegedly) so were unable to comment on why it happened.

Why would the cooling fans come on with a gearbox issue?!

A work colleague has suggested it may be to do with the O/GPF trying to undergo a regeneration cycle but unable to complete due to my short journey to work (6 miles). He has the same issue on his diesel dpf car, except the gearbox hanging, as his is a manual (could my car be hanging in lower gears to increase the temp to aid regen?). His issue is solved by a long, hard drive. I'm going to se if this sorts mine this evening.

Comments welcome?

I literally had the fan issue on my 2019 C43, 14k miles put it in for a check no issues at all, had all the software updates etc and the specialist also mentioned he thought it was trying to do a regen cycle. Weird it only started to happen when the temp dropped and I also had a drop in MPG. I had this for 4/5 months and just put it down to being normal, I tried the long drive didn’t do anything. But it’s now been 10 days since I have had the fan come on I don’t know if it’s because the temp has risen but I also didn’t start the car for 3 days, so maybe that gave it some sort of ‘reset’.

 

[fatzwithaz]

I literally had the fan issue on my 2019 C43, 14k miles put it in for a check no issues at all, had all the software updates etc and the specialist also mentioned he thought it was trying to do a regen cycle. Weird it only started to happen when the temp dropped and I also had a drop in MPG. I had this for 4/5 months and just put it down to being normal, I tried the long drive didn’t do anything. But it’s now been 10 days since I have had the fan come on I don’t know if it’s because the temp has risen but I also didn’t start the car for 3 days, so maybe that gave it some sort of ‘reset’.

Took mine out last night and drove it like I stole it for 45 minutes. This morning's drive to work now normal with no gear hanging or cooling fans on after turning engine off. Could be a one off but I suspect my work colleague was right!

 

[sunste]

I also feel that this hapens in the winter (after the last upgrade of the ECU from the dealer, didn't notice this before that). I can also se that the turbopressure goes realy high, and goes up and down, it feels like the engine strugle with the low rpm. So maby the gearbox is the problem and don't shift down when it should. When you drive in sport or sport+ there is no problem.

C43 AMG 2020

 

[RobMea]

Did anyone get to the bottom of this? Mine hadn’t done it for the last 6 months, but has started running the fan again this week. Can’t be temperature related as it’s not remotely cold at the moment.

Did a 30 mile motorway run yesterday with no effect.

 

[RobMea]

Did anyone get to the bottom of this? Mine hadn’t done it for the last 6 months, but has started running the fan again this week. Can’t be temperature related as it’s not remotely cold at the moment.

Did a 30 mile motorway run yesterday with no effect.

And MPG instantly dropped…

 

[f17ant]

Did anyone get to the bottom of this? Mine hadn’t done it for the last 6 months, but has started running the fan again this week. Can’t be temperature related as it’s not remotely cold at the moment.

Did a 30 mile motorway run yesterday with no effect.

I don’t know if this helps but if I have a spirited drive and drive like a granny like 5 mins sometimes the fan does run if I drive like a granny last 10 mins no fan. I think it’s just related to oil and gearbox temps.

 

[f17ant]

Did anyone get to the bottom of this? Mine hadn’t done it for the last 6 months, but has started running the fan again this week. Can’t be temperature related as it’s not remotely cold at the moment.

Did a 30 mile motorway run yesterday with no effect.

Sorry re read and just seen you said not temp related I have a diagnostic tool if your close to Essex and want to scan the car