Coolant
 

What is the best coolant for a 12A? Keep in mind that I live in the desert which gets very hot.

Here in Oklahoma where it gets moderately hot, I run with green. From what I've read a while back I think that might be the safest option for our engines. I could be wrong, but I've haven't had any issue in 100*+ temps in 3 years here with it.

A couple years ago, someone suggested Mercedes Benz coolant as it supposed to be very non corosive and friendly on anuminum like what our radiators and housings are made out of. It's pricier than the store brands and I can't say any worse or better at high temp protection, but I've saw how normal coolant can coorode aluminum engine parts over time. Not pretty or encouraging if you plan on keeping the car a long period. Anything you run would benefit from regular changes.

I just ran with green in mine as well. I should take pics of my old water pump for ya, it was one of the most disgusting things ever. I'd highly recommend frequent changes of coolant no matter what you run.

gets hot where I am at ... just using the green in ours

You've got an aluminum radiator in your -7? Because most of us just have brass radiators in ours, which came from the factory.

I use green in mine, and it routinely is driven in temps up over 110F with asphalt temps closer to 150F+.

As the above poster mentioned - change it frequently; that's the trick to ensuring that you don't get any corrosion or buildup issues, as the water is what gets boiled off over time and the mixture gets more and more biased to antifreeze vs. water. Mix 50/50, obviously, and change it every 2-3 yrs. HTH,

I run Benz coolant 50/50 with DISTILLED water. $$ but that's just me...
As said: change every 3 yrs. Remember, its the WATER that is the most efficient cooler, not the coolant, so unless your winters take you w-a-a-a-y down in temps, 50% of water is best for the hot days.
Q: have you EVER had your rad pulled and professionally chem-dunked at Rad Shop? great coolant mix useless if the rad is sludged up!

Stu Aull
80GS
Alaska

Don't know how often it freezes there, but if it's like never, then just run distilled water with maybe a little water wetter.

Yes 7Aull I just had the stock rad re-rodded at a local shop, so I'm guessing "green" is normal prestone antifreeze. I heard that water wetter eats seals, which is why if your running it you will have brown sludge in your overflow tank that looks like someone took a dump in it.

GMB water pump
 

Anyone use a GMB aluminum water pump? I got one, the bearing seemed stiff, and the starter couldn't turn the engine over with the pump installed. I have an RMA for the pump, but not sure if I should order a replacement (manufacturing defect) or go with an OEM replacement (design defect).

GMB is huge in the aftermarket ... it's probably an isolated issue