Thermostat?

[Oliver Reilly]

Hi guys,

First post here!

New to Mercedes coming from a Renault Megane RS265. The arrival of my daughter a while ago and a new one on the way has forced me to grow up but I refused to rough it, so I found myself a lovely 2014 C220D wagon.

Anyway, I got myself an icarsoft computer to read the fill levels on the DPF. They jumped from 60% full to 290% in around a week. I tried a forced regen and that didn’t work. The only thing that changed was the fill level went up to around 360% whilst trying to force the regen. The engine light has come on and the revs won’t go over 3k. This isn’t a problem, as coming from Renault, I am used to getting my hands dirty! I’ve found a video on how to clean the DPF, but I’ve noticed the temp fluctuating up and down whilst driving. Will rise to 90degs whilst engine is under load, but then drop to 80degs when not under load.

First question - is this why my DPF hasn’t been regenerating due to a faulty thermostat?
Second question - what thermostat do I need? I thought they were the little metal disc things and when I search, it seems the whole housing with thermostat built in needs to be bought, ranging from £30 - £130 in price. If anyone can show me a picture or a link of what is needed, then that would be amazing! I don’t want to buy the wrong part and have trouble when I come to swap it over.

Thanks in advance for your help, Oliver.

 

[LostKiwi]

A faulty thermostat will definitely prevent a regen.
There are a number of prerequisites for a regen to happen and if any one of them isn't met it won't happen.
Some of the prerequisites:
1. Engine at normal temperature
2. No engine management fault
3. A certain level of fuel in the tank

There are more but they're the common ones.

 

[onefortheroad]

Buy the stat from mb dealer. Others maybe cheap but last half as long.

 

[malcolm E53 AMG]

^ As above buy the part from MB - stats nowadays are more complex and communicate with the engine management system a faulty one can lead to a DPF malfunction.

 

[Oliver Reilly]

Thanks for the replies guys, I’ll contact Mercedes tomorrow and get one sent over and get it fitted at the weekend. I don’t really want to get one from eBay as I’m sure I’ll select the wrong one. Mercedes will be able to send the right one from the reg number I’m sure. What kind of cost am I looking at?

 

[LostKiwi]

Thanks for the replies guys, I’ll contact Mercedes tomorrow and get one sent over and get it fitted at the weekend. I don’t really want to get one from eBay as I’m sure I’ll select the wrong one. Mercedes will be able to send the right one from the reg number I’m sure. What kind of cost am I looking at?

Phone MB Grangemouth and mention the forum. They do forum discounts and will send it out for £5

 

[onefortheroad]

Thanks for the replies guys, I’ll contact Mercedes tomorrow and get one sent over and get it fitted at the weekend. I don’t really want to get one from eBay as I’m sure I’ll select the wrong one. Mercedes will be able to send the right one from the reg number I’m sure. What kind of cost am I looking at?

Be best part of 100 quid . Maybe more

 

[ajlsl600]

For a thermostat!!!

 

[EmilysDad]

For a thermostat!!!

EmilysMum's Citroen C3 has an ECU controlled motorised valve instead of a conventional waxstat thermostat .... IIRC it was around £160 plus fitting!

 

[ajlsl600]

I hope my ml don't have that... More robbery!

 

[ajlsl600]

Shxx.! A quick search shows around 75 quid!!! As usual it comes with its environmentally friendly plastic casing which I don't need.........

 

[malcolm E53 AMG]

The OM642 stat for the 350cdi engine is £130 plus fitting

 

[EmilysDad]

Shxx.! A quick search shows around 75 quid!!! As usual it comes with its environmentally friendly plastic casing which I don't need.........

Mine came from Citroen though they are probably available as a pattern part as I believe the engine is a BMW lump.

 

[Oliver Reilly]

Phone MB Grangemouth and mention the forum. They do forum discounts and will send it out for £5

Thanks LostKiwi! Just ordered the parts now from MB Grangemouth. I had a good look at the thermostat in my engine bay and discovered that someone hadn’t clipped the air box on properly, wearing a nice big groove into the hose that goes from the rad to the thermostat
Expected to get shafted on parts and was pleasantly surprised to find that the stat and pipe came to £88.75 delivered! Took the chassis number so I know it’s going to fit. Excellent result. Thanks for all of your help guys!
Anyone know what coolant it will take and how much? Makes sense to flush the whole system whilst I’m there

 

[LostKiwi]

The coolant spec should be in the handbook but is usually G48 for MBs.