E220 CDI - Engine operating temp.

[Monique]

Hello tech gurus,

I noted our E touring runs cooler than any previous car in my life. It runs at 65-75 C.

Of course, depending on design and placement of the temperature probe, the temperature may vary.

However, the car is a diesel and should perhaps run hotter to minimize pollution.

Can anyone offer an explanation??

Thks

 

[Dieselman]

Simple:
Diesels don't need to run hotter to burn the fuel properly as fuel condensation isn't and issue.
Diesels don't waste as much heat into the cooling system as they turn more of it into motive power hence the system runs cooler.

Give it a really good thrashing and it should heat up more.

 

[DrNick]

My turbo diesel ran cool when I first got it. This was down to a stuck open thermostat. Had it changed and it ran warmer, but didn't make any noticable difference to the car (smoothness, fuel consumption etc)

 

[Monique]

Thanks to both of you. The engine is very smooth and gives good power.

Will keep an eye on the thermostat also. The cooler temps should be a giveaway if it is fuqued

 

[Monique]

Back again.

My car runs at 65C. I consider this too low. What is the recommended operating temp? What does MB recommend??

Thank you

 

[Dieselman]

80-C. Try a new stat.

If you are just pottering about the engine may not be wasting enough fuel to heat up properly with the heater on.

 

[Monique]

Thank you... can someone tell me where the stat is on a 220CDI?

Some are out of reach of the DIYer with home equipment.

 

[DieselE]

Your posts are all based on the assumption that your temperature gauge is giving a correct reading.

If the engine continues to perform well as you say and on cold days you get a really good output from the heater after about 10miles (16km in your part of the world. ) it might just be the temperature gauge reading low.

That's not to say all the advice you've had is wrong, I'm just offering an alternative.

 

[Monique]

Fair enough.... but the heater is anemic at best... gauge reads 60-62 after 100 kms on highway, goes up in traffic.

Think the stat is a good start point.

Thanks for the suggestion.

 

[Monique]

Case closed. Was the stat. Car now operating at 82C as per the print on the stat.

What should have been a vsimple job turned into a chore. I had to buy a set of Torx sockets and of course dropped one of the bolts into the abyss under the engine... then the magnet I had for such retrieval was gone. I loaned it to a friend some months back and he did not return it. Bad but also good. Bought a new HD magnet with longer extension. Will work good on all my cars.

Thank you to all those who helped.

 

[andyturner]

I have the same issue with my 320 CDI. Was your thermostat expensive and did it include temp sensor and housing? Did you need to drain the system?

Andy