M272 June 2008 SL350 Thermostat - what temperature for steady state?

[Mr Greedy]

Posting for a fellow forum member @sausage

Code scan using iCarsoft revealed code stating thermostat not closing fully resulting in slower warm up (I don't have the code number).
Temperature seemed to be at 93°C via live data feed.

What temperature should the steady state temperature be for this thermostat? Does anyone know?
Looking at the parts associated with the MB part number seems to suggest 100°C (e.g. look at the Autodoc link below).


Check on 7ZAP using VIN reveals part number A2722000415 (which replaces A2722000115).
Thermostat is now electronically controlled, and there for expensive than the passive wax-only type thermostat.

£130 from MB Newcastle on eBay
https://www.ebay.co.uk/itm/131837751393

Could possibly risk a Mahle for £70, but a lot of people have had issues with non-MB on the W212 OM642 diesel engine
https://www.autodoc.co.uk/mahle-original/8269051

Would be worthwhile having a full coolant change whilst the stat is being done if there is no record of this. Use genine Merc coolant, which is rated for 15 years, but most would change anywhere from 10 years.

 

[mioba]

With the stat out is ideal as you can really flush the system well. close it all off without the stat and fill with water, run, empty, repeat.

Then put it all back together with fresh juice.

Dont bother with an aftermarket stat if original had lasted 10 years, a super-ceded part should be better.

It wont need touching again for hopefully another 10.

Edit: Just noticed its not a drop in stat, but still with stat out is a good time for backflush

 

[Mr Greedy]

Thanks

My question on the steady state temperature is because a lot of the Mercs run at around 90 degrees C.

E.g. OM642 diesel is 88/89 deg C and I *think* my more agricultural M271 3.0 V6 petrol ran at 90 deg C steady state.

 

[mioba]

The temps are atill arounf 90 degrees, its only 1 deg temp difference you mention, a new stat will be right regardless and ensuring of course the coolant mix is right.