EdGs
Senior Member
Got a late start on my Nephew's 2018 Laramie, 140k miles and a cracked radiator. He's had it for the last 25k miles or so.
I made a couple boo-boo's on this. I should have left the old radiator in until we got the coolant pretty well flushed out, but I did not.
Brain fart.
I should've pulled the block drains, but did not.
Anyway, got the old one out and the carquest replacement in. His thermostat was really stuck like chuck in the bore. So much so, that when it finally popped out, the gasket remained on the engine. Once it was peeled out, we cleaned the bore where it sits.
As you all know, a drain and fill does not remove much old coolant, so we had 12 gallons of distilled water on hand.
At 140k miles and no previous coolant service, we drained the reservoir. What little fluid it had left looked pretty crappy.
What came out with the radiator was not any better:

I put my gutless thermostat in and filled her up with distilled water, and when we ran it for 30 seconds or so the clean water turned brownish very fast and developed a white froth quickly.
Several drain and fills later, it was a little lighter, but still crappy. So, finally we took the top hose off the rad and i plugged the hose neck with my hand, filled the radiator with clean water half-full into my coolant funnel and ran the engine for 15-20 seconds with a couple revs to push the dingy coolant from the top hose into our collection pan.
After a few rounds of this, it was getting clearer, but still had the white froth. It smelled like coolant and was not oily as far as I could tell.

It got really late and we were down to the last couple gallons of distilled water, so I filled the rad with a jug of 50/50 coolant I had.
We ran the engine long enough to start pushing out the 50/50 mix, shut her off, reconnected the top hose, and installed my spare 192°Calorstat I just got from RockAuto. Filled the rad with about 3 qts. of OAT concentrate.
I did notice that once I added the first 50/50 coolant, and cycled the engine to push it all the way out the top hose, the amount of froth dininished greatly. Not sure why, but I will take it.
Heater her up until the t-stat opened and added a bit more concentrate 'til she was full. Temps stable so far, got up to 206° or so, and quickly dropped into the mid 190's, even upper 180's. Probably not quite a 50/50 equivalent, but will take it for now.
HIGHLY RECOMMEND the Calorstat 192° thermostat, thank you again @Ken226.
Here's the progression of very dirty to still a little dirty, but good enough for this go-round.
From dirtiest on right to good enough for now on the left:

It has to be 50 times better than it was before.
Going to recheck it later.
I made a couple boo-boo's on this. I should have left the old radiator in until we got the coolant pretty well flushed out, but I did not.
Brain fart.
I should've pulled the block drains, but did not.
Anyway, got the old one out and the carquest replacement in. His thermostat was really stuck like chuck in the bore. So much so, that when it finally popped out, the gasket remained on the engine. Once it was peeled out, we cleaned the bore where it sits.
As you all know, a drain and fill does not remove much old coolant, so we had 12 gallons of distilled water on hand.
At 140k miles and no previous coolant service, we drained the reservoir. What little fluid it had left looked pretty crappy.

What came out with the radiator was not any better:

I put my gutless thermostat in and filled her up with distilled water, and when we ran it for 30 seconds or so the clean water turned brownish very fast and developed a white froth quickly.
Several drain and fills later, it was a little lighter, but still crappy. So, finally we took the top hose off the rad and i plugged the hose neck with my hand, filled the radiator with clean water half-full into my coolant funnel and ran the engine for 15-20 seconds with a couple revs to push the dingy coolant from the top hose into our collection pan.
After a few rounds of this, it was getting clearer, but still had the white froth. It smelled like coolant and was not oily as far as I could tell.

It got really late and we were down to the last couple gallons of distilled water, so I filled the rad with a jug of 50/50 coolant I had.
We ran the engine long enough to start pushing out the 50/50 mix, shut her off, reconnected the top hose, and installed my spare 192°Calorstat I just got from RockAuto. Filled the rad with about 3 qts. of OAT concentrate.
I did notice that once I added the first 50/50 coolant, and cycled the engine to push it all the way out the top hose, the amount of froth dininished greatly. Not sure why, but I will take it.
Heater her up until the t-stat opened and added a bit more concentrate 'til she was full. Temps stable so far, got up to 206° or so, and quickly dropped into the mid 190's, even upper 180's. Probably not quite a 50/50 equivalent, but will take it for now.
HIGHLY RECOMMEND the Calorstat 192° thermostat, thank you again @Ken226.
Here's the progression of very dirty to still a little dirty, but good enough for this go-round.
From dirtiest on right to good enough for now on the left:


It has to be 50 times better than it was before.
Going to recheck it later.
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