Engine Coolant Capacity And Mixture For 2005 Suburban

wtk1562 · June 27, 2009

I just had my coolant flushed and replaced and I am concerned that my mechanic didn't do a 50/50 mixture (water and coolant). If he put 100% coolant how could i tell andd what are the dangers. I know he used 1 and 1/2 gallons of coolant but unsure of the capacity. Please help.....

DBVille · June 27, 2009

Welcome!!!

It may depend on the engine & if you have aux heat & AC. Do you have your owners manual?

Go to an auto parts store, and get a hydrometer to measure the temp the coolant will freeze at. Should be less than $5. It will tell you how low the freezing point is, and should be able to get an idea of the percentage of anti-freeze. Normally it is 50-50. Pure antifreeze will not dissipate heat as well, and you could overheat. Probably some other issues as well.

After I finish lunch, I'll go downstairs and check the capacity of my 2005 Suburban, and let you know. I suspect it is ok. Did he use 100% coolant, or the pre-mixed kind?

tramz · June 27, 2009

Welcome and see attached for capacities. If it was a complete system flush your only half capacity. If he only drained the radiator you should be OK. I use nearly 100% coolant/antifreeze and have never had an issue, but since GM started using Dex-cool, I stay with the recommendations in the OM. With the

cost of coolant these days, it's probable that he used pre-blended 50/50.

capacities.pdf

redvett · June 27, 2009

A 100% antifreeze mixture will freeze in very cold temps and as posted above is a very poor heat conductor and you will probably will have overheating problems.

tramz · June 27, 2009

A 100% antifreeze mixture will freeze in very cold temps and as posted above is a very poor heat conductor and you will probably will have overheating problems.

I don't disagree at all, but nearly 100% was actually like 80-85%. Here in Florida, don't have to worry about very cold temps and want it to be a poor heat conductor.

DBVille · June 27, 2009

My owners manual (2005 Suburban, like the OP) says 16-17 Qts, plus 1 liter for rear heat. 16.2 for the 6.0, and 17 for the 5.3 (yes, thats what it says). So, completely drained, it should take about 17 qts. The OP used 1 1/2 gallons or 6 Qts.

If he used 100% coolant:

Assume 17 Qts total, 6 qts. anti-freeze, 35% anti-freeze - too low.

If he used pre-mixed coolant:

Assume 17 qts total, 3 qts (6/2) anti-freeze, 18% anti-freeze - even lower.

In either case, it would appear to be low. I am guessing that it was flushed with water, and the radiator was re-filled with pre-mixed, giving the worst case scenario. I would go talk to the mechanic and figure out what he did, and have him drain some out and add pure antifreeze - the premix will not get you there now.

redvett · June 27, 2009

Here in MI -25F is plenty for freeze protection and much better for overheat protection. The only way to be sure is to check the actual AF/water ratio with a hydrometer. Anything else is a guess.

A 100% antifreeze mixture will freeze in very cold temps and as posted above is a very poor heat conductor and you will probably will have overheating problems.

I don't disagree at all, but nearly 100% was actually like 80-85%. Here in Florida, don't have to worry about very cold temps and want it to be a poor heat conductor.

tramz · June 27, 2009

Here in MI -25F is plenty for freeze protection and much better for overheat protection. The only way to be sure is to check the actual AF/water ratio with a hydrometer. Anything else is a guess.

A 100% antifreeze mixture will freeze in very cold temps and as posted above is a very poor heat conductor and you will probably will have overheating problems.

I don't disagree at all, but nearly 100% was actually like 80-85%. Here in Florida, don't have to worry about very cold temps and want it to be a poor heat conductor.

If I lived in MI or any other northern state I would have had a different approach. What I did worked for me and for 22 years this is the way I did it and never once had a radiator, cooling or heating issue. When I purchased my '05 I changed my method and now follow the OM guidelines because of dex-cool. BTW-If you know how many qts of coolant to how many qts of water, its not a guess, its an approximation.

redvett · June 27, 2009

Guess or approximation its still not as accurate as a hydrometer. The only reason the MFR's recommend 50-50 is to protect their investment not knowing where all the vehicles will be sold and simplifying assembly procedures. I myself have used this method on all my vehicles for pleasure and my business vehicles. The highest mileage truck has 251000 mi with only a water pump replacement and rad hoses, the heater hoses are original. Works for me.

Here in MI -25F is plenty for freeze protection and much better for overheat protection. The only way to be sure is to check the actual AF/water ratio with a hydrometer. Anything else is a guess.

A 100% antifreeze mixture will freeze in very cold temps and as posted above is a very poor heat conductor and you will probably will have overheating problems.

I don't disagree at all, but nearly 100% was actually like 80-85%. Here in Florida, don't have to worry about very cold temps and want it to be a poor heat conductor.

If I lived in MI or any other northern state I would have had a different approach. What I did worked for me and for 22 years this is the way I did it and never once had a radiator, cooling or heating issue. When I purchased my '05 I changed my method and now follow the OM guidelines because of dex-cool. BTW-If you know how many qts of coolant to how many qts of water, its not a guess, its an approximation.

c4cruiser · June 28, 2009

Most shops buy both the old green ethlyene glycol and the newer Dex-Cool or compatible coolant in bulk and it is already in a 50% mixture. These mixes use a distilled water to make up the supply. Having pre-mixed coolant makes it easy for a service tech to do a coolant system service and not "guesstimate" how much concentrate and how much water must be put into the system.

Depending on the type of "flush" done, it can be difficult to use a concentrate and water mix to get the correct proportions. Some shops will simply drain the radiator which leaves some amount of old coolant in the block and heater core. A mechanical flush using a pumping system will remove all of the old coolant while refilling with the proper mixture.

A 50-50 mix protects to -37 degrees F and that is good enough for just about any climate in the continental US be it Miami FL or

International Falls, MN. Even driving around in sub-zero temps, the wind chill factor for the air going into the radiator, that mix will work fine.

wtk1562 · June 29, 2009

I just had my coolant flushed and replaced and I am concerned that my mechanic didn't do a 50/50 mixture (water and coolant). If he put 100% coolant how could i tell andd what are the dangers. I know he used 1 and 1/2 gallons of coolant but unsure of the capacity. Please help.....

Thanks guys for all the replies, I know we used Dex-cool and don't beleive it is premixed. I will check with mechanic as to his process. Where can I get a hydrometer and what is the cost? Thanks again for all the help.

DBVille · June 29, 2009

I just had my coolant flushed and replaced and I am concerned that my mechanic didn't do a 50/50 mixture (water and coolant). If he put 100% coolant how could i tell andd what are the dangers. I know he used 1 and 1/2 gallons of coolant but unsure of the capacity. Please help.....

Thanks guys for all the replies, I know we used Dex-cool and don't beleive it is premixed. I will check with mechanic as to his process. Where can I get a hydrometer and what is the cost? Thanks again for all the help.

Go to an auto parts store, and get a hydrometer to measure the temp the coolant will freeze at. Should be less than $5. It will tell you how low the freezing point is, and should be able to get an idea of the percentage of anti-freeze.

Answer is above.