Author Topic: Engine Coolant Question  (Read 420 times)

Offline Jak220

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Engine Coolant Question
« on: January 06, 2022, 10:19:12 AM »
Not 100% sure this is the right thread but didn't see a better option, if so just lmk and I'll move it. I have a 1984 K10 with a sbc 400 in it that I inherited relatively recently, been doing a bunch of work on it. I noticed the coolant in the radiator seems to be the normal yellow Prestone stuff, I was doing some research and people seem to disagree on whether or not it HAS TO BE dexcool or not so I wanted to hear you guys' thoughts. I know you definitely arent supposed to mix dexcool with any other coolant but it seems to be entirely just normal antifreeze. I drove it once before i took a look at the coolant and noticed it wasn't dexcool but it reached operating temperature fine and never overheated or had any other issues. Should I just leave it be or is it really worth flushing the whole system and replacing it with dexcool?

Offline bd

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Re: Engine Coolant Question
« Reply #1 on: January 06, 2022, 11:51:53 AM »
Your '84 uses regular ol' green, propylene glycol coolant.
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Shifty

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Re: Engine Coolant Question
« Reply #2 on: January 06, 2022, 12:19:26 PM »
Dexcool didn't exist when your truck was made. 
87 V20 Standard Cab Longbed (current)

87 R30 3+3 Longbed (days of yore)

98 C2500 ext cab longbed

Offline LILT77

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Re: Engine Coolant Question
« Reply #3 on: January 06, 2022, 02:41:41 PM »
Use the green flavor
77 C10/Big 10 Cheyenne "Old Blue"
81 C2500 Sierra Grande "Gramps"

Offline wz7u

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Re: Engine Coolant Question
« Reply #4 on: January 06, 2022, 03:43:40 PM »
Dexcool killed the gaskets on my Impala. It's been hard flushing that stuff out, but it went to green because it doesn't eat stuff up like DC does.

Dexcool is of the devil.
'79 C20 454/th400 "Pearl"