My truck is over heating

[Ahmad Alfilchawi]

Hello guy how are you

 I got 2015 Chevrolet Silverado and the last month I install transmission cooler with deleting the thermostat for the transmission. also I included coolant thermostat for the engine which is Mishimoto. the Engine temperature before installing the engine thermostat when the truck was on the oem thermostat the engine temperature was between  180F to 210F it doesn't go over that range. But today I noticed that the engine is overheating and I don't know the reason why I check the coolant fluid and it was on the level.  Also I checked the fuses for the cooling fans they were in good condition. Do you recommend me install back the OEM thermostat to check if it's on the thermostat or not. In my opinion maybe it could be from the transmission cooler because it is blocking some air from the radiator?.  

And if you have any suggestions to diagnose the issue. 

[davester]

Do the large radiator hoses and radiator get hot when the engine is overheating?  Maybe you installed the thermostat backwards or the thermostat isn't working right?

[Lsgun1]

Did you bleed the air from the cooling system?

[Ahmad Alfilchawi]

Actually no I didn't try to bleed the air because I didn't drain the whole cooling water, but actually I have figured it out  one of my friends had the same issue he told to change the thermostat and get back the oem or jets thermostat. 

[Lsgun1]

You opened the cooling system, therefore air was introduced whether you drained it out completely or not.