W210 Low Coolant Temperature

[Bahnsturmer]

Hi all. I hope you can help me. I have recently acquired a W210 320CDI estate. The car had been little used/unused for the last 2 years. I have noticed that the coolant does not appear to come to temperature and the gauge shows a temperature between 40 and 60 C. This is even after driving for over longer periods of (half an hour +). Fuel consumption seems high: only 30mpg on motorway. Am I right in thinking that this likely to be a thermostat problem or the temperature sensor?

 

[Blobcat]

I'd change the thermostat

 

[malcolm E53 AMG]

+1 - stat needs changing it’s a common failure mine went at 60k miles and yes the car takes over half an hour to warm up to temperature in fact it hardly ever gets there

 

[grahamcol]

As above. The low temperature seems to affect fuel consumption rather a lot with the CDl engines in my experience and it should improve noticeably once the stat has been renewed.

 

[Naraic]

Yep, one more, change the stat...it's a normal thing for this car.

 

[Bahnsturmer]

Thanks to all for your replies. I have ordered a new one and shall be replacing asap. BTW is it crucial to drain the cooling system completely? I would like to get away with a partial drain if possible.

 

[Steve@Avantgarde]

Thanks to all for your replies. I have ordered a new one and shall be replacing asap. BTW is it crucial to drain the cooling system completely? I would like to get away with a partial drain if possible.

Youll find youll lose about 2-3 litres of coolant when pulling the stat, the whole system holds 5, they are easy to bleed out so you may as well change the coolant and do it properly, especially if its not been done for a number of years. I would.

 

[Bahnsturmer]

Thanks Steve, I'll do that.

 

[mioba]

another one for stat. Mb stats are like butter.

ideal to flush the coolant with stat out as you can flush the block.

MB coolant is 15 years so do it now and its good for the next 15 years .... lol

 

[Bahnsturmer]

 

[ajlsl600]

I'd change the thermostat

Hope it not some modern shite design that involves a forced change of housing and stat. When all u need is a 5 quid stat.

 

[Blobcat]

Hope it not some modern shite design that involves a forced change of housing and stat. When all u need is a 5 quid stat.

W210 so should be good

 

[Bahnsturmer]

@asjl600: I had thought that a belt and braces approach by ordering a stat with housing and sensor and gasket was the way to go. So that is what I ordered. I will keep the old housing and sensor in case the quality is sub par.

 

[LostKiwi]

Hope it not some modern shite design that involves a forced change of housing and stat. When all u need is a 5 quid stat.

Yep... Just ordered a genuine stat for the R class - £153!

(Ducks under bench and waits for ajlsl600 to spontaneously combust )

 

[Bahnsturmer]

Update: Changing the thermostat did the job. Engine now running at around 85 degrees and fuel consumption much improved.

Thanks all

 

[malcolm E53 AMG]

Beautiful engine especially when it’s running at temperature I still miss mine

 

[mioba]

Update: Changing the thermostat did the job. Engine now running at around 85 degrees and fuel consumption much improved.

Thanks all

Top job, had the same issue on my w220 years ago. Stats do alot of opening and closing and get worn.
The difference on fuel economy, running and heating was night and day.
Glad you are sorted !!!

Did you change the coolant too.

 

[Bahnsturmer]

Yep changed coolant too.


Sent from my iPhone using Tapatalk

 

[ajlsl600]

Yep... Just ordered a genuine stat for the R class - £153!

(Ducks under bench and waits for ajlsl600 to spontaneously combust )

F me!! How that not pure robbery

 

[LostKiwi]

F me!! How that not pure robbery

Knew that would get you going!

It comes with the obligatory aluminium housing and has some kind of electronic interaction via a connector on top.

But yes it's ridiculous for something that does the same job as a £10 wax stat.