Background. 360/5.9 in 1500 4WD. Did the plenum repair with the Hughes kit. Installed new 190 thermostat also from Hughes.

Problem. After reassemble and following the “burping” procedure recommended in several threads here, the following happens.
indicated temp on dash will go over 210 after 20-30 minutes at idle, hot coolant comes up the radiator (using the burping funnel), lower hose very hot, passenger side radiator header very hot. upper radiator hose cold, but full of coolant, driver side radiator header cold. After several minutes running like this, coolant flows up and overflows the burping funnel. Shut down the engine, after a few minutes, all the coolant in the funnel (close to 1/2 gallon) is sucked back down into the radiator and then some (air sucked in), after cooling down, takes close to 1/2 gallon to refill the rad to the top. (Probably close to the volume that overflowed the funnel. Repeated this 3 times, with same results.

question.
is the new thermostat bad, as the upper hose and driver side radiator header never get hot?
or is this standard procedure no just need to keep trying?
I didn’t check this ‘new’ thermostat in boiling water before installing.

appreciate any advice. Not a Novice, but First time working on a vehicle without an air bleed screw.

Mike

 

As you found out the "“burping” procedure" doesn't work. The t stat will trap air in the top of the motor. Drill a small hole in the stat or find one with an air bleed like in post #14 here.

 

Is the belt for the water pump routed properly? Almost sounds like it's running backwards.

 

Thanks.
Guess that the t-stat needs to come out and meet up with the drill.
About The belt routing, thought the same about the Waterpump behavior. Belt is routed according to the sticker on the front bulkhead and the pre-work photo I took. Really only works 1 way.

let me know any other ideas.
will post up when I get this solved this weekend.

 

Got her done.

“New” t stat #1 was defective.
“New” t stat #2 tested Ok. 1/8 hole drilled. “Burner” clean of bubbles in 20 minutes.

adivse anyone replacing t stat to give it the hot water bath test before investing time standing bent over the rad.

 

You didn't get a Failsafe thermostat at first did you? Every one of those I've dealt with failed. Either it was bad when it came to me or it failed soon after. I put one in a Ford Taurus once. Fortunately, those are easy to get to on top of the engine. It didn't last 24 hours and failed 30 minutes into the drive after installation.

I'm assuming you used a 195 thermostat unit as that is the most common.

 

Stant superstat thermostats have never failed me - unfortunately, they are harder to find with all of the parts company buyouts, but seem to still be available if you look around a bit -

 

Now boxed as Motorad....

 

I have not used the Motorad version to-date. I still look for NOS Stant Superstat thermostats, since I'm unsure of what Motorad may have done to the quality of Stant thermostats post-takeover..