Possible coolant leak after timing belt change

jase1

There does seem to be a significant body of anecdotal evidence on the web that mixing VAG G12 coolant with *anything* else, be it red or blue, can cause problems and sludging. This could be where this comes from, and it is not exactly recommended practice.

I have come across two articles purporting to be written by experts (one was a senior engineer from Texaco-Chevron in the US) which state that mixing IAT and OAT coolant types will cause no adverse effects, but that the 5-year lifespan of the OAT variety is cut to the 2-year life of the IAT if the two are mixed in sufficient quantities.

Also, putting in OAT (pink) into some old engines will cause sludging even if the IAT isn't present. There is speculation that the apparent effect of "mixing" is in fact caused by using OAT at all in these older engines.

Certainly the fact that HOAT (hybrid OAT, which is what most generic coolant mixtures are) exists, which is little more than a mixture of the two plus some additives, I am inclined to believe this.

The coolant has been in the car now for six hours, and I just drove the car for half an hour. The two have mixed without apparent sludging so far, and the only difference is a slight purpling of the overall mixture.

Earlier today I believed that the only difference between red and blue was the additives involved and that mixing was OK. I've gone right around the houses on this one and have returned to the same basic view. However this doesn't mean that I won't be vigilant regarding the wellbeing of my car's cooling system.

It seems that the garage didn't actually replace the coolant, they merely topped it up after sorting the other work. This is fine, as the coolant was in good condition. But given that the car is now four years old, I will replace it as a matter of course within the next couple of months regardless of the outcome of my little faux pas.

mikey72

I looked at antifreeze mixes.
All antifreeze types come in a variety of colours.
Occasionally, if everything goes wrong together, some mixes can form a small amount of a jelly like stringy substance, as some of the additive settles out.
At other times, you can mix a tub of everything together, and it'll be fine, but possibly a strange colour.
Some older cars can't use OAT, but need the older "blue" antifreeze, but no-one can quite explain why.
I think the answer is if you look in the expansion tank, and there is nothing floating about, or even settled in the bottom, you're ok.
If you are changing, flush through, run with water a couple of times, then flush and refill with whatever suits the car.

Flying-High_2

jase1 wrote: »

There does seem to be a significant body of anecdotal evidence on the web that mixing VAG G12 coolant with *anything* else, be it red or blue, can cause problems and sludging. This could be where this comes from, and it is not exactly recommended practice.

I have come across two articles purporting to be written by experts (one was a senior engineer from Texaco-Chevron in the US) which state that mixing IAT and OAT coolant types will cause no adverse effects, but that the 5-year lifespan of the OAT variety is cut to the 2-year life of the IAT if the two are mixed in sufficient quantities.

Also, putting in OAT (pink) into some old engines will cause sludging even if the IAT isn't present. There is speculation that the apparent effect of "mixing" is in fact caused by using OAT at all in these older engines.

Certainly the fact that HOAT (hybrid OAT, which is what most generic coolant mixtures are) exists, which is little more than a mixture of the two plus some additives, I am inclined to believe this.

The coolant has been in the car now for six hours, and I just drove the car for half an hour. The two have mixed without apparent sludging so far, and the only difference is a slight purpling of the overall mixture.

Earlier today I believed that the only difference between red and blue was the additives involved and that mixing was OK. I've gone right around the houses on this one and have returned to the same basic view. However this doesn't mean that I won't be vigilant regarding the wellbeing of my car's cooling system.

It seems that the garage didn't actually replace the coolant, they merely topped it up after sorting the other work. This is fine, as the coolant was in good condition. But given that the car is now four years old, I will replace it as a matter of course within the next couple of months regardless of the outcome of my little faux pas.

If in doubt drop it flush and refill.... Simples... I run ECPs Red in all mine... Both Vauxhalls and the ML. Supposed to last longer than the Blue but it gets dropped at Cambelt swaps anyway... For what it costs just do it;) Under £11 for 5litres last time;)

forgotmyname

Also heard the same rumours, Mixing different types can cause issues, Thickening/jelly like state which
seems to get worse with higher concentrations compared to weaker mixes.

Just a thought i have some of both types in the shed will have to try mixing them neat

Tucker

forgotmyname wrote: »

Just a thought i have some of both types in the shed will have to try mixing them neat

Let us know if the shed is still standing in the morning!

cyclonebri1

Tucker wrote: »

Let us know if the shed is still standing in the morning!

And that unfortunately is the belief the pocket emptiers thrive on:eek:;);)

jase1

Well, I discovered the cause of the leak!!!!

One of the new core plugs hadn't seated fully and was leaking. Unfortunately this led to a breakdown on the way to work, as it popped out completely.

Nothing to do with the coolant which was still fine.

This has granted me a free coolant replacement but stripped me of half a day's pay (I am a contractor)

Hopefully this will be the end of it -- the coolant is holding up now.

cyclonebri1

cyclonebri1 wrote: »

Hopefully just an air lock in the system that has now found it's way to the expansion tank. As above carefull monitoring needed.

The only other worries are that the core plugs they replaced would have been plugging the water gallery, could be a source of the leak.
Park it up over paper to check.;)

Ahem, :A,

Oh, the core plugs don't "seat" as such, they are simply knocked in flush with the block with sealant applied to the flanges, in fact they can actually be hammered straight through if not carefull. A bit of a get out by the garage to be honest.

Wig

No idea really on anti freezes, but you guys seem to have already done some research.

AFAIK red/blue/pink means little, it either ethylene glycol or something else

You shouldn't mix the ethylene glycol with the 'other stuff' whatever that maybe.

AFAIK Toyota use red stuff that is not ethylene glycol