E320 cdi l6 2004 low engine temp

[Malcy43]

Hi all. Just joined your great site tonight and just bought my first MB today. A 2004 e320 cdi avantgarde 1 owner FSH 48000 on the clock very low miles. Drove it home about 50 miles give or take and noticed on the coolant temperature gauge it ran about 3 to 4 bars like maybe about 50 degrees or slightly more or less. The car ran beautiful totally faultless but kind of concerned that it is running way to cool?. Mpg says it was getting 36 mpg so not to bad.
Should I leave it be or is this a thermostat problem to all of you think?.
Question is will this damage the car in any way as it's not getting up to temp or am I being paranoid?.
If it is the thermostat I have read that it can be changed easy enough for a diy person. If I did change the housing would I need to use gasket sealant or just bolt it on as it is.
I am really worried that I have bought a bad one but as I said it drove faultless at 75 all the way home it was just the 3 to 4 bars on temp gauge as that's about 50 degrees I think.
Look forward to your replies.
Malcolm

 

[dan-mb]

Your temp gauge seems a bit low but give it a long run say 1 hour on the motorway and see if that gets your temp up to 'normal'. 36ish mpg is about what you should expect, more on motorway runs.

 

[Malcy43]

Ok will take it another run tomorrow and see what's it's like and get back in touch with you on here. Thanks

 

[Ted]

The thermostat is faulty.
Change it and enjoy even better fuel consumption, a heater that works properly and less engine wear.
You will be glad you did.

 

[merc85]

Thermostat and temp sensor well worth changing as above Welcome btw

 

[t-dawg1]

The thermostat is faulty. Change it and enjoy even better fuel consumption, a heater that works properly and less engine wear. You will be glad you did.

+1 I had the same issue when I bought my last C220 turned out a faulty thermostat and car ran much better afterwards and warmer cabin too

 

[SLKNick]

If the engine is not getting up to temperature then it will probably cause the engine to run richer. This will cause increased fuel consumption and may cause the diesel particulate filter to clog up prematurely (if it has one). So better get it sorted sooner rather than later.

But beware if this is your first diesel, they take much longer to warm up than a petrol equivalent (ie 5 times longer), particularly if you drive it slowly and in colder weather.

 

[abecketts]

This thread has been helpful, my w210 e320cdi also runs well below 80 degrees C on the gauge so I will talk to the garage; cheers

 

[Malcy43]

I have it booked into a local garage for Tuesday morning next week the mechanic said its most definitely the thermostat snd will change it for me. Will keep you guys up to date on what happens when it's done. This must be one of the lowest mileage merc e320 cdi on a 2004 out there. 48000 miles

 

[Malcy43]

I am used to diesels but my other car is a 2010 bmw 535d m sport I like my diesels big and powerfull. First drive in my merc it seems much smoother than my bmw