Which brand thermostats?

[Lmmbrad33]

Is there a gasket under the t-stat housing or is it just a machine fit? And the rubber on the thermostat seals it?

 

[Robby Avery]

Correct, machine surface the oring type gaskets on the thermostat create the seal. Just fwiw I take the stats out reseat the housing pull the drain plug out of radiator and flush til clear water is seen with hose in coolant reservoir just make sure any and all dexcool is properly flushed than install new stats and vac and fill as long as 28 in of mercury is held for 5 minutes I fill it and it's out the door:thumb:

 

[duramaxzak]

I've used the Mishimoto low temp thermostat's and never had any issues.

 

[JoshH]

I have always had good luck out of the Mishimoto thermostats. Unlike most aftermarket thermostats for our trucks, they actually have the rubber seal that seals the thermostat closed instead of a metal on metal seal.

 

[OregonDMAX]

I got mishimoto in mine, low temp for AZ. I'm in love with them.

 

[Robby Avery]

Just an fyi to look out for, I put new AC DELCO OEM styles in my LB7 the 1st of the year. They came in the GM boxes and looked to be the real deal. Put them in and they don't open until 190 and 195. I haven't really worried about it as I don't mind it running a bit warmer since I don't tow much anymore. But it went from running 180 idling and 185 running down with my old stats(before the rubber seal failed on one), to idling at 188-190, and running 195 down the road.

The ferm I've been thinking about the temp subject for awhile now since the last post I wonder if a company like dei radiator relief for diesels would help lower temps back to 180-185 or is it snake oil in a bottle like other claimed products?

 

[Robby Avery]

Just fwiw has anyone tried the dei radiator relief for diesels? Or is it a hype? Just curious if the stuff works