Slow warm up on W209 cdi

[Tacho D]

I find that it takes ages for the 220 CDI engine to reach operating temperature. I suspected the thermostat, but I thought it is more common for these to fail shut, causing overheating. As the coolant is due for replacement, it may be worth replacing the thermostat anyway. In addition, the heater delivers heat as all or nothing, regardless of the temperature setting. Are the two issues related?

 

[onefortheroad]

I find that it takes ages for the 220 CDI engine to reach operating temperature. I suspected the thermostat, but I thought it is more common for these to fail shut, causing overheating. As the coolant is due for replacement, it may be worth replacing the thermostat anyway. In addition, the heater delivers heat as all or nothing, regardless of the temperature setting. Are the two issues related?

The 2 I've had fail , were open , some just open too soon . Diesels have to be driven hard if you want a fast warm up time.

 

[redjules51]

I find that it takes ages for the 220 CDI engine to reach operating temperature. I suspected the thermostat, but I thought it is more common for these to fail shut, causing overheating. As the coolant is due for replacement, it may be worth replacing the thermostat anyway. In addition, the heater delivers heat as all or nothing, regardless of the temperature setting. Are the two issues related?

My 220 cdi always takes a few miles. Longer in winter months I hasten to add. Definitely check the thermostat though. When I replaced faulty one it had stuck open.

 

[Wighty]

If it’s cheap enough and you have the coolant to do , just replace it at the same time anyway , they don’t last forever .

 

[AlanGunn]

I can feel heat start coming from the vents on mine in around 3 minutes driving out of the estate.
It then takes 10 to 15 minutes to get up to temp normal driving.
Does that sound right (new to mrec).

 

[Tacho D]

Yes apparently, they are not the quickest to warm up, but as it turned out, mine wasn't going past 60 degrees and that was effecting economy. So changed it, a little fiddly, and changed the coolant at the same time as that was overdue. Now running at normal temperature with good economy.