Whisperhead

Hello all.

I have to top up my coolant in my '94 C4 LT1. I can see that there is Green coloured coolant in there, and I understand that I'll need to use the same spec. coolant else I could have issues with coagulating coolant etc.

I have purchased some Comma XStream G48 coolant, that conforms to BS 6580:2010.

I know that the owner's manual states GM spec 1825M is to be used, but when asking for it the vendor told me that this is the stuff I needed.

It doesn't specifically state GM 1825M on the bottle, and is a dark green/blue colour. I'm worried pouring this in as a top up could damage the engine if it isn't compatible with what is in there already.

I know it's a rather generic question about a very specific product, and I'm sorry if it's a dumb thing to ask, but can anyone tell me if this is OK to use? I'd rather look stupid and ask first

Link to product is below:

http://www.commaoil.com/passenger-ve...view/563/XSG1L

c4cruiser

Your '94 uses a green coolant that is an ethylene glycol solution. Searched the Amazon UK website and came up with this coolant that meets the GM1825M spec. You may want to look at the specs of this coolant and see if what you bought has any similar specification or make/model suitability.

The green ethlyene glycol coolants should be flushed and refilled every 2-3 years. So if the coolant in the car is that old, you may want to do a complete flush/fill with fresh coolant. The Amazon listing doesn't say if it's a concentrate or not.

antfarmer2

Sounds like it might have been changed to the old school green. Do not mix the it will be a mess. What ever you decide to use pull your knocks and flush it good first. I recommend new knocks.

ddahlgren

If you only need to top off any quality ethylene glycol will be fine. If due for change I would put it off until winter and the car laid up in the garage. Personally I plan all the large things for the winter and only deal with must do now items in the summer.

antfarmer2

How can you be sure what he has?

A Peter C4

Owners manual says ethylene glycol= green from factory .Not newer orange type.I have been useing Peak long life ethylene glycol.Keep useing this type.Even when you do system flush.

antfarmer2

My 94 had orange in it at 43thou so not sure.

A Peter C4

Peak website says standard green, GM 1995 and earlier.

ddahlgren

Have you ever seen green DEX Cool? Me either...

Whisperhead

Thanks for the replies it literally only requires a top up for now but previous owner did tell me he had replaced all the fluids. Apparently just not enough of it. I will be doing a complete flush as recommended over the winter with a proper GM spec coolant, this exercise is really just to get rid of the low coolant light for now. I suspect there may be a minor leak someplace. The vast majority of comments I've read have recommended the green coolant in any case so I think I'll stick with it. Thanks again all

antfarmer2

If you're putting it up I would do a pressure test to be sure it is not a bad head gasket. You could ruin your engine.

antfarmer2

Have seen a blue green that might not play well. Just better safe than sorry.

ddahlgren

Asa kid never got the big box of crayons so pick 1 of 8 colors and I am ok. Fuscia have no idea. Salmon is wide open as talking farm raised or Copper River Canyon? Farm stuff this pale sickly looking crap that screams throw me out I have gone bad to the good stuff a very deep pink to almost red. Green is easy had that crayon in the box of 8. LOL

antfarmer2

I remember kids like you always had teeth marks in their crayons and most were paste eaters.

Christi@n

I Go with prestone concentrate (yellow can) in every vehicle i have, you can easily find it up there

ddahlgren

I was the kid taking everything apart to see how it worked and when bored with that pull little girls hair LOL

antfarmer2

I used to pick old lawnmowers and take them apart and learned how to fix them after awhile.

RUU

Also possible the cooling system wasn't bled properly after the change. Even then it can take a few heat cycles before all the air is purged from the system.