I just got a used 1997 Cobalt with a 7.4 Mercruiser and Bravo 3.
What type of coolant should I be using for this engine? It has a closed cooling system.
I took it out for the first time today and noticed it was a little low.
Thanks
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I just got a used 1997 Cobalt with a 7.4 Mercruiser and Bravo 3.
What type of coolant should I be using for this engine? It has a closed cooling system.
I took it out for the first time today and noticed it was a little low.
Thanks
GM dexcool 50/50%
What color is the coolant that is in there?
Reason I ask is you want to only add the same type.
Green is traditional glycol.
Orange is Dexcool.
I have seen red, forget what that was.
Yellow? heavily diluted glycol possibly?
Might be a good time to flush your system and then put in what the manufacturer recommends.
Just my .02
Yellow is probably an anti-freeze like G-05 or G-48. This is a good option for aluminum components in engine. If you not servicing cooling system regularly, I wouldn’t use Dex-cool.
Since I don't know what kind is in the system now can I just add water to top it off and then when I take the boat out for the season in the fall...have the system flushed at that time and have the right stuff put in then?
Texaco makes an universal anti freeze that is yellow also. We use it a lot at the shop. It seems to be a really good anti freeze. Being not sure of what’s in there, imo this would really be a good choice. Drain and refill with a 50/50 mix. We replace all our Dex cool and green anti freezes with this. Out g type anti freeze get the G-05 or G-48 back
Without knowing how much coolant to water ratio you already have, i would not answer that. When you say that the system is low, how low is it?
A little low CAN be OK as when it heats up it, thermal expansion comes into play.
They're is still some visible in the reservoir but it is 1/4" below the min cold line even when the engine is warm.
So if I'm going to flush and add new what would be the best product to put in? The Texaco universal?
If it were mine I would find out why it's low first.
Attachment 444913Just what I would use plus it’s safe to be mixed with most anti freezes. We mainly use 3 anti freeze, the universal in all dex cool and green anti freezes plus the G antifreeze that someone’s already switch to any other anti freeze, the G05/G48 for those that call for it (mostly import) and chevron delo (CAT approved) anti freeze in diesels. Any doubt and it gets the universal, the stuff has held up very well and seems to be very corrosive resistant, stays clean without breaking down.
Anti freeze is also anti boil. It raises the boiling point along with 10-15psi of pressure. I would only add 50/50 not just straight distilled water.
Their it should be a type tester available to see what’s in it, can’t remember if it is carried in stock though at the part stores.