I may have done a bad thing...

My new (to me) Blazer (2001) has leaked coolant since I bought it a few weeks ago. I noticed after a couple of days. Then when I made sure it was full, with no air pressure in the system, it seemed to stop leaking. Then on my way home one day it almost red-lined hot a couple of miles from home (my commute is about 65 miles round-trip). As far as I know, it was the top radiator hose and coolant outlet at fault, both had holes in the same place.

Now, my mistake is that while this is going on I bought coolant from a convenience store and a NAPA auto parts store (both green), but after reading the label of the NAPA fluid, it is for '95 and older vehicles. Then today, after hopefully buttoning up the leak with a new upper radiator hose, thermostat, and coolant outlet, I added DEXCOOL "compatible" orange fluid.

I have read various accounts about how this is or is not a problem, and I am now asking it here: How big of a problem is this, and how soon do I need a full coolant system flush? I am planning on doing this anyway very soon, but I wanted to repair any leaks first. So if I drive it like it is for under 350 miles, will that lead to major problems with different chemistries of coolant?

Thanks in advance,
Matt

 

I had a situation, first hand, where mixed types gelled in the system. I was lucky, I wasn't traveling far from home and my radiator was shot anyway. I do not recall what types I mixed. Every vehicle I drain, gets flushed and filled with green. I never had a problem with it and I like only needing one product on hand.

 

Thanks for the input. Mine had green when I bought it. I am wondering though, since my owner's manual clearly states to only use DEXCOOL if I should do that after flushing. Maybe the common issue of the lower intake leaking is due to people using the wrong coolant?

 

Negative. Coolant type has nothing to do with leaks. Every auto manufacturer calls for their own, special fluids but none of them make them and it's uncalled for. The one that cracks me up the most is the transfer case. Most of them are made by an outfit in Syracuse, NY and I know that Ford, GM and Dodge all use them but they all have their own specified fluid to fill them with. I'd be really surprised if there was much difference in the innards of those from one motor company to the other. There are some issues of newer anti-freeze types being incompatible with some of the older parts but I haven't heard of anything that's not compatible with green anti-freeze. If someone knows different, I'd like to hear it.

 

Thanks again. It looks like I am still stuck. I just ran it at idle in park, after installing upper radiator hose, coolant outlet (inlet?) / thermostat housing, and new thermostat, and she is still leaking. I fear it may be the dreaded lower intake manifold gasket issue...

 

Coolant is a black hole of confusion. The reason that your owners manual calls for Dexacool (OAT) is so that you don't add a coolant that is not compatible with the factory Dexacool like some green (IAT) and make sludge and presumably to sell more Dexacool. So mixing can be a problem, sometimes. Some manufacturers also want certain coolant technologies for certain metals/materials/gaskets, something that started coming up with aluminum, nylon, etc. Some believe that this may be a factor in our LIM adventures. There are many variations on these technologies, like silicate free... There are also hybrid coolants that mix OAT and IAT so mixing is not always bad. It gets worse because the colors are not standardized. Even green ain't green because it can be based on EG or PG. I just went through this with a Mercedes. In addition some claim to be universal. So mixing is bad and not bad at the same time.

I gave up a long time ago trying to be a coolant expert because the interwebs will drive you nuts with the misinformation and confusion. In my mind there are two strategies. Pick one and use it in everything and forget about metal and plastic compatibility and corrosion concerns or use the OEM in each vehicle. A good single choice would probably be a "universal" coolant where the Prestone nerds are at least trying to not get sued due to internal engine damage but I still don't know about mixing, especially if you are not the original owner. You mix at your own peril, ask me how I learned that 20 years ago. Because of this if I am not confidently adding the same coolant that I know is in there now, I flush first with water and then stick with what I just chose as I did with the aformentioned Mercedes coolant rabbit hole adventure.

BTW, we have a Chevy Malibu in the family that is past 100,000 miles. I just changed out the pristine and trouble free Dexacool recently with GM branded Dexacool. Dexacool is not automatically bad.

In case you want to geek out on coolant or just like torturing yourself, attached is a summary chart. Be careful, there will be no coming back after this chart. I use green everywhere and Dexacool sucks will be a long lost simple rule, especially if you have vehicles from other brands/continents and you want to get 200,000+ miles out of them without LIM like problems.

George

 

Thanks, George.

Yeah, I am getting that there is a lot of confusion out there. I may do myself and my head a favor and skip the article you mentioned. I have been down far too many rabbit holes already, but thanks for the info.

I have decided to flush out the mix, clean the system and go with a "universal" green. Green was what was already in it, so if it is bad, then I guess the damage is already done...

Still working on the leak(s) as well.

 

If I am not mistaken I think Prestone "universal" is an amber color but don't quote me on that.

George

 

I had not looked at this in a while, so while I was eating lunch - holy crap. Here is Prestone:

Max ALL vehicles - Yellow
Platinum All vehicles - Yellow/green
ALL vehicles - Yellow

and yet we still need:

Max American - Orange
Max American - Purple
Dex-cool - Orange
Max Asian - Red
Max Asian - Blue
Max Asian - Green
Max European - Blue
Max European - Pink
Max European - Violet

I think I need a nap,

George

 

It is yellow (maybe amber) for the extended life, "all makes and models". According to O'Reilly's info, the O'reilly, PEAK, and Prestone have the same specs. The bottle indicates up to 10 year / 300,000 mile life, which is double what is shown on O'Reilly's comparison chart.

Matt