Rusty Coolant

[oddnumber]

Afternoon chaps, I picked up my 1.9 T25 today, and am chuffed as hell with it.

The coolant is unfortunately an horrible sludgy rust colour. I plan to replace this with 50:50 G12 coolant, but I was wodering if this signifies something more sinister than lack of use?

Thanks, as ever!

[Wychall]

Not possible to say without history or analysis of the coolant. My advice would be to flush the system thoughly with a hose pipe, then fill and take it for a run with just plain water, drain and refill (again plain water) and keep repeating until the water becomes clear. Then drain and refill with your G12. Then only time will tell.
Good luck.

[oddnumber]

Thanks for the reply, much appreciated. There was fresh coolant added by the new owner fairly recently, but I doubt if it was flushed.

What would cause it to turn rusty so quickly? Head gasket would be mayonnaise in the oil, surely?

[Wychall]

The excessive rusty-ness I would put down to incorrect, or no, antifreeze in the past.

Oil contamination from the head gasket, or any where else, would put an oily film on the surface of the water. Combustion gases from the head would not show, unless it was bad enough to cause bubbling in the header tank. None of it would cause a rusty appearance.

And yes, water in the oil would cause mayonaise.

My money is on bad maintenance in the past allowing sludge to build up in the water jacket and rad. This needs to be flushed out, either each component seperately, or by using the technique that I mentioned in my first reply.

[CovKid]

Its important to disturb any silt when you start flushing. The bottoms of water containers invariable end up with quite a layer of the stuff and you may need to stir this up with a long screwdriver to help it out of the system. Mine was the same. I also used a flushing agent which also helped clear minor blockages in the heater rad then gave it two 20 mile runs, replacing with fresh water each time before doing the final 50/50 antifreeze fill. My heater now works a good deal better and the system is at least clean now.

As said, the rusty stuff is the result of neglect.

[oddnumber]

Thanks very much for that, much appreciated.

I grabbed the following pic - looks like sediment floating on top rather than the typical head gasket mayo. No oil slick floating either.



Any opinions? All greatly received.