COOLANT

[BBBAD94ZR1]

What is the best coolant to run in a 94 lt5? Im going to service my cooling system this week and would like to know your thoughts. Use distilled water or not?

Thanks in advance.
Ray

[tomtom72]

Hi Ray, GM spec # 1825-M GM still sells this but the parts dept. at a local chevy dealer may not keep it in stock because it is a sillicate based corrosion inhibitor and the newer GM cars use a different corosion inhibitor chemical. Please do not do anything till you get the correct 1825-M coolant. Do not use the newer GM stuff.

I don't know that color means anything as you can dye a liquid any color you want. Dex-cool II or what ever it's called is the "red" stuff GM uses now and it has no sillicates in it. Our systems were designed to work with sillicated, 1825-M coolant and not the newer non-sillicated coolants. If you buy coolant from the parts store read the label to find the active ingredients or look at the "medical warning" label & you should find the corrosion inhibiitor system used.

There is a thread here about this stuff and over at CF/ZR-1 section there is some evidence from one of the tuners of the damage he thought was caused by using the wrong spec coolant in an LT5. The head gaskets swelled & failed.


Tom

[Z Factor]

Originally Posted by tomtom72

There is a thread here about this stuff and over at CF/ZR-1 section there is some evidence from one of the tuners of the damage he thought was caused by using the wrong spec coolant in an LT5. The head gaskets swelled & failed.


Tom

You will find that a search here will produce just about anything we need to know ZR-1/LT5 wise.

For instance, here is a thread on the subject;

http://zr1netregistry.com/forum/show...hlight=coolant

[Aurora40]

I'd second what Tom said. I'd play it safe and go with the ACDelco/GM silicated coolant. And I'd use distilled water to dilute it definitely.

[tomtom72]

Ray I just remembered this item. Sorry! Over at the netregistry site in the "maintenance section" there is a "how to" section that has a write-uop on how to make a screen to protect the air intake for the radiator. It's worth reading and doing....man do C4's suck up lots of jumk off of the road....the term used was C4's breath air to the cooling system thru the splitter under the bumper so they vacuum the roads very effectively!