# Yanmar 336 D Thermostat



## TractorNewb (Apr 3, 2021)

Hi Folks
I am a newbie with tractors. bought a tractor with a property a yanmar 336 d. have some issues with overheating.
There is no thermostat in the radiator. My question is should there be?
My local tractor shop says no but i see them on the internet.
My Yanmar is about a 1993 model.
Thanks for any help


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## winston (Aug 19, 2008)

It should have a thermostat. THERMOSTAT: Yanmar Tractor Parts (hoyetractor.com) 

I doubt the missing thermostat is causing the overheating. Dirty radiator inside and or outside would be most likely. Could be loose fan belt but not as likely.


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## bmaverick (Feb 20, 2014)

TractorNewb said:


> Hi Folks
> I am a newbie with tractors. bought a tractor with a property a yanmar 336 d. have some issues with overheating.
> There is no thermostat in the radiator. My question is should there be?
> My local tractor shop says no but i see them on the internet.
> ...


Like Winston mentioned, could be dirty on the inside of the radiator. 40+ years of scale or slime in the bottom of the tank can cause slow flow. Likewise, the fins being clogged on the outside. 

Now, there is also another tending issue for overheating, the air-intake filter. When this gets clogged or dirty, the engine temps rise as well because the operator just gives the engine more throttle to achieve the power needed. I've been there twice with this. Caught me off guard the first time. Now I know better.  

Other items to check is the water pump (if equipped) and the belt.


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