Coolant issue FYI

Interesting post, Rick.

I know that late-model Chrysler cars are supposed to use the next marketing breakthrough (gimmick?) - which is the GL-5 grade of coolant. AFAIK, Zerex is the only maker of it. It is supposed to eliminate supposed problems of DexCool/Prestone Extended Life.

I've seen some technical articles on the GL-5 posted on a Chrysler forum

- I'll track them down and post unless someone beats me to it.

Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")

I mis-typed - it's G-05, not GL-5 (I think I must've been thinking of a type of Subaru brake fluid or transmission grease or something).

I got my education on it from thread on a Chrysler 300M forum

. The definitive post said: "Bill, you are right about DexCool being anOAT coolant. However, G-05 is an HOAT (hybrid organic additive tech)coolant, which unlike DexCool does have silicates in it. Chrysler foundthat the silicates prevent cavitation erosion of the aluminum water pumpimpeller. Indeed, water pump failure was the main reason they did not gowith DexCool as an extended life coolant. The gross difference seems to be that the G-05 has low silicates (*not* silicate-free) - apparently it has been determiend that silicates provide some benefit in the coolant system (water pump).

Does that mean it is the best to use in all cars? Who knows. The laws of physics are the same everywhere, but maybe there are subtle differences in materials or finishes. If I read the info. on the G-05 correctly, it should be "best" for all cars.

An informartive post from another Chrysler forum:

's an article referenced in that post: Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")

yeah GL-5 is a gear oil rating.

AFAIK the sludge problem caused by Dexcool was because dealerships were putting in stop leak pellets at time of PDI's. I suppose it had to be a normal GM practice to put theese pellets in their rad's before the vehicle left the dealership, but appearently since the switch to Dexcool this practice didn't stop, until GM finally put out TSB to dealers to stop adding pellets.

I have to wonder about the use of stop-leak pellets in a brand new car anyway. Maybe it is standard procedure with every manufacturer, but it doesn't seem useful to put stop leak into something that's new and therefore shouldn't be leaking.

-Matt

Hi,

I don't know how many manufacturers do (did?) this, but my mid-80's Toyota pickup came from the factory with some kind of sealer, and I understand Ford has also used it at some time. Why? Bill probably hit it having to do with certain manufacturing processes...

Rick