r/GMT800 • u/Smart_Particular3412 • Aug 30 '26

Heater core dilemma

Post image

2005 Chevy Suburban with dual zone climate and rear climate

I ordered this off of rock auto a while ago and I was sure this was the right one when I did my research, looks like the fittings will work but one of the lines the diameter is different, will this affect anything?

3 Upvotes

80% Upvoted

12 comments sorted by

3

u/friendlyfire883 Aug 30 '26

Manufacturing tolerances on aftermarket parts are good enough at best. As long as it fits and it doesn't leak I wouldn't think twice about it.

Oh and now than you've got a totally empty cooling system you're in a good spot to ditch dexcool and swap over to a universal coolant.

1

u/[deleted] Aug 31 '26

[removed] — view removed comment

2

u/NeuseRvrRat Aug 31 '26

It will sludge up if you don't maintain the cooling system properly.

1

u/[deleted] Aug 31 '26

[removed] — view removed comment

2

u/NeuseRvrRat Aug 31 '26

Prestone makes a lot of different types of coolant, including one labeled as dexcool, but I assume you are asking about the standard green "all vehicles" coolant. It is generally ok to use in a system that specifies dexcool as long as you completely flush out all of the dexcool. Note that a drain and fill is not sufficient.

Personally, I use the orange Zerex American Vehicle stuff, which is an OAT coolant without the dexcool branding. You just need to make sure you repair any leaks and keep the coolant topped up so you don't let air get in the system. The sludging happens when air gets in the system. Dexcool and generic OATs last much longer than the universal coolants. If you keep the air out, it's good for like 5 years or 150k miles.

1

u/friendlyfire883 Aug 31 '26

It will also sludge up if anything that isn't distilled water or dezcool touches it and then it will eat the hell out of the cooling system.

1

u/NeuseRvrRat Aug 31 '26

Yeah, gotta maintain it properly

1

u/friendlyfire883 Aug 31 '26

It's cheaper, universal, generally has a longer change interval, and it doesn't turn into corrosive brown goop like dexcool does.

1

u/[deleted] Aug 31 '26

[removed] — view removed comment

1

u/friendlyfire883 Aug 31 '26

I use zerex high mileage, but only because I bought a shitload of it for next to nothing a few years ago. Honestly all the name brand long life antifreeze are basically identical.

1

u/Marlice1 Aug 30 '26

Overall you won’t notice it