Volvo MD11D thermostat question # 2

[bliss]

I recently posted some questions about my older Volvo engine overheating - i subsequently have had the exhaust manifold off - it was pretty clogged up so I
had it acid washed and am ready to put it all back together - i also bought a new thermostat just in case there was an issue with that - the thermostat i have bought is a different shape to the previous one - it is part # 876080 - which when i have searched the internet seems to be the correct part - although it does replace the previous obsolete part - the issue is that it seems too large ( deep i.e. ) to fit - and i can't get the thermostat housing watertight when i put it all back together because the new thermostat is too deep ….

has anyone had this problem ???

I am tempted to grind the required couple of mm off the base of the thermostat but seems a bit odd i need to do this ….. but the part # seems correct

in the attache photo the new thermostat is on the left ...

[model 10]

You need to get a different thermostat. Don't worry so much about part #'s If it fits correctly it will work. Don't mess with the one that does not fit. If you really want to go big, get a "fail safe thermostat"( quits open.) I really don't understand why all thermostats are not "fail safe. Why do you have to go after market to get a decent thermostat? It must be a conspiracy.

[Shawn67]

Test your old thermostat in boiling water and see if it opens properly. If it does clean it up and put it back in.

If it doesn't you probably will need to get another thermostat to make it fit properly. Be sure you check to make sure it is the same temperature rating. Your old thermostat should be labeled with the temp and it is likely 60c. Volvo has a few thermostats that look just like your original that are hotter for fresh water cooled engines. You don't want one of them in raw water cooling, it will clog you up again fast.

Good luck,

Shawn

[bliss]

There is an interesting footnote to my question about the thermostat not fitting into the thermostat housing - i was telling the story o a Volvo mechanic this morning when he asked me if i had read the instructions - now i'm a busy man - i don't usually have time for instructions but they do clearly say that in certain older models you need to either remove or whack in the pipe at the back of the housing 3 mm ..... there you go ... interestingly it doesn't quote my model but i think i that must be the solution