I was changing my water pump and also decided to replace the thermostat as well and noticed on the thermostat a small hole with a tiny bearing on the top of the thermostat. I read that this was to purge air within this area, so I purchased (what I thought) was an OME part rated for 203 degrees and found this somewhat not the same so i called the dealer up (where i bought it at) and spoke with a "diesel tech" he made mention that the thermostat i bought (without the small hole and bearing) would be ok. is this guy feeding me a load or is this ok to install?
please advise.
thank you.

 

Some thermostats have a hole or notch some don't. Some have a "jiggle" valve resembling a ball bearing. Myself, I prefer the ones with a hole or notch. If the one I intend to use doesn't have a notch, I drill a very small hole (<1/16 inch) on the thermostats flange for my gasoline engines.. It will allow any trapped air BEHIND the thermostat to pass on by before the thermostat opens. This can be especially true after the cooling system has been opened up for any part replacement.. Thermostats need hot liquid behind them, to gradually open, large air pockets behind thermostats will prevent the thermostat from opening, thus overheating the engine.
Sounds like you have an OEM stat , so you should be good to go.