Is mixing coolants REALLY that bad?
Discussion
I replaced a thermostat and temp sensor on a 2004 1.9 TDI Passat on the weekend, lost some coolant so bought some G13 from VW and topped it up. When disposing of the old coolant I noticed it was green, and the VW G12/13 is pink. Googling this, lots of websites said do not mix them under any circumstances as the coolant can turn to a jelly like substance? Anyone ever had this happen? How likely is this?
The car is on 145k and 140k of that was with the previous owner, what is the likelihood of this gelling happening, and if so how quick does it do it? is it weeks or years? Should I rush out tonight to get some more coolant or wait until the weekend to do a full flush? Or not bother and leave it, as the car hasn't got many years left in it to be honest.
Thanks
The car is on 145k and 140k of that was with the previous owner, what is the likelihood of this gelling happening, and if so how quick does it do it? is it weeks or years? Should I rush out tonight to get some more coolant or wait until the weekend to do a full flush? Or not bother and leave it, as the car hasn't got many years left in it to be honest.
Thanks
It depends on exactly what's in the coolants and hence is very hard to give a definitive answer. I think 99% of the time you'll be fine to mix two coolants which use the same anti-freeze base, but are you willing to risk the 1% chance of there being a nasty reaction which causes the coolant to solidify?
Colour is not really a good guide. Some coolants of different colours will be fine together, some of the same colour will not.
How quickly any chemical reaction will take place will depend on exactly what the reaction is which will depend on the two chemicals in question so again it's impossible to answer without knowing the exactly constituents of each antifreeze. Most likely you'll be fine to wait to the weekend, but it's always possible you will not.
Colour is not really a good guide. Some coolants of different colours will be fine together, some of the same colour will not.
How quickly any chemical reaction will take place will depend on exactly what the reaction is which will depend on the two chemicals in question so again it's impossible to answer without knowing the exactly constituents of each antifreeze. Most likely you'll be fine to wait to the weekend, but it's always possible you will not.
Edited by kambites on Monday 21st May 10:11
Riknos said:
Cool cheers guys, I'll order some more G13 in and get it changed on the weekend, car will do 50 miles total before changing it so hopefully should be fine.
Drain off a sample and keep your eye on it, I suppose you could heat and cool the sample a few times, the thing is if there is a reaction you may be too late to save some componentsJust like engine oil is a blend, regular automotive Coolant/Antifreeze is a blend, typically glycol based, each brand will have a slightly different blend of different glycols and additives. You are changing the blend slightly, but the worst case is that are altering the performance to favour cooling or antifreeze, very slightly. I've mixed for decades without issue.
4x4Tyke said:
Just like engine oil is a blend, regular automotive Coolant/Antifreeze is a blend, typically glycol based, each brand will have a slightly different blend of different glycols and additives. You are changing the blend slightly, but the worst case is that are altering the performance to favour cooling or antifreeze, very slightly. I've mixed for decades without issue.
It's not the different makes (blend) that could cause an issue. If the OP has changed a silicate free anti freeze with G13 (which contains silicates), there is a real chance than they will form a thicker jelly like substance. Thats What She Said said:
4x4Tyke said:
Just like engine oil is a blend, regular automotive Coolant/Antifreeze is a blend, typically glycol based, each brand will have a slightly different blend of different glycols and additives. You are changing the blend slightly, but the worst case is that are altering the performance to favour cooling or antifreeze, very slightly. I've mixed for decades without issue.
It's not the different makes (blend) that could cause an issue. If the OP has changed a silicate free anti freeze with G13 (which contains silicates), there is a real chance than they will form a thicker jelly like substance. http://www.benzworld.org/forums/r129-sl-class/2475...
You won't have to read the whole sorry saga, just the last few pages where he solves it.
PositronicRay said:
If you don't believe mixing different coolants is a bad idea, take a look at this.
http://www.benzworld.org/forums/r129-sl-class/2475...
You won't have to read the whole sorry saga, just the last few pages where he solves it.
After reading through it all it was the radiator that was the problem, not wrong coolant, well the way i've read it anyway. http://www.benzworld.org/forums/r129-sl-class/2475...
You won't have to read the whole sorry saga, just the last few pages where he solves it.
I'm mixed coolant for years with no side effects, certainly never had a garage tell me oops, your coolant has 'solidified'??
Mind you, i do remember reading years ago about not mixing coolants, if i' m doing small top ups of coolant i'll use any antifreeze, but if i'm doing a complete coolant change then try and get all the same type, as recommended by your car manufacturer, common sense really.
robbocop33 said:
PositronicRay said:
If you don't believe mixing different coolants is a bad idea, take a look at this.
http://www.benzworld.org/forums/r129-sl-class/2475...
You won't have to read the whole sorry saga, just the last few pages where he solves it.
After reading through it all it was the radiator that was the problem, not wrong coolant, well the way i've read it anyway. http://www.benzworld.org/forums/r129-sl-class/2475...
You won't have to read the whole sorry saga, just the last few pages where he solves it.
I'm mixed coolant for years with no side effects, certainly never had a garage tell me oops, your coolant has 'solidified'??
Mind you, i do remember reading years ago about not mixing coolants, if i' m doing small top ups of coolant i'll use any antifreeze, but if i'm doing a complete coolant change then try and get all the same type, as recommended by your car manufacturer, common sense really.
robbocop33 said:
After reading through it all it was the radiator that was the problem, not wrong coolant, well the way i've read it anyway.
I'm mixed coolant for years with no side effects, certainly never had a garage tell me oops, your coolant has 'solidified'??
Mind you, i do remember reading years ago about not mixing coolants, if i' m doing small top ups of coolant i'll use any antifreeze, but if i'm doing a complete coolant change then try and get all the same type, as recommended by your car manufacturer, common sense really.
Mixing coolant isnt a problem as long as you arent mixing OAT and non OAT coolant.I'm mixed coolant for years with no side effects, certainly never had a garage tell me oops, your coolant has 'solidified'??
Mind you, i do remember reading years ago about not mixing coolants, if i' m doing small top ups of coolant i'll use any antifreeze, but if i'm doing a complete coolant change then try and get all the same type, as recommended by your car manufacturer, common sense really.
Mix those two and you'll get jelly.
4x4Tyke said:
yea, g10 an g11 dont mix but g13 is the slut of the coolant world and goes with anything. Gassing Station | Home Mechanics | Top of Page | What's New | My Stuff