Today was hot and sunny here in Melbourne, Aus.

so I took the family to the to the beach....wouldn't you know it no parking anywhere.

After 15min or so looking for a carspace in the hot sun the temperature gauge started to creep over the 90 degree mark. I quickly pulled over suspecting a coolant leak, I opened the hood and was horrified to see what looked like froth on top of the coolant in the reservoir tank.

I let the car cool down then I opened the tank and was shocked to see a creamy sludge (kind of looked like melted strawberry icecream, lol).

- I fell to me knees in horror and raised my hands towards the heavens and I shouted at the top of my lungs, "NOOOOOOOOOOOOOO!!!"

 

ever mix the purple/pink G12 with the green coolant?

 

I think what cocoacrustation was trying to say is that mixing coolants could cause it to thicken or if u have no water mixed in with the coolant lessens it's ability to cool the engine

 

Hopefully it's just a coolant problem but check your oil too... it could be mixing via the oil cooler or via a bad head gasket. Oil mixed with green coolant can look like a milkshake or melted cheese so with the color of G12, a strawberry milkshake/ice cream seems plausible.

 

lol nice addition of the dramatic reaction you had.

 

Yes I've heard of this type of scenario with generic coolant & g12 on this forum, but I wish that was the case for me. There is definitely oil seeping into the cooling system. Question is: Head gasket or Oil cooler? Any suggestions??. There was a bit of water spraying out of the exhaust in the past...so I'm leaning more to a head-gasket.

I spent most of the today draining and flushing the cooling system, (about 20 times I think), I added some additive ("cargo, metallic seal-up") into plain water in the reservoir which apparently can repair head gasket problems with oil to water contamination.

I'll give it another flush tomorrow and add some clean water to see if the additive has worked. I dought it though.

 

Just out of curiosity, what can or will happen if you continue driving the care with sludge in the cooling system apart from overheating the engine?

 

I drove fine with a failing oil cooler for a few months.

Not saying I knew that was the issue, and ignored it, but saying it is doable. I kept having to add oil because it was leaking into the cooling system, but all in all Its "ok".
Good luck flushing the system though

 

The oil cooler is more common and cheaper to boot.

 

I have a feeling replacing the oil cooler would be significantly cheaper and easier than the head gasket, so I would start with that and go from there. If that doesn't help, ecstuning.com has HG kits and the head bolt tool for pretty cheap, if you have the tools, patience, and know-how to do it yourself. Good luck.