My engine temp started spiking last night when sitting at lights so I pulled into the servo this morning to top it up with water and when I took the radiator cap off there was a white foam that bubbled over. Does anyone know what this is? I flush and fill my radiator every 10k when I change the oil so I would have thought the radiator is in fairly good condition. It may or may not be related too but since last night there has been a light ticking noise coming from the engine too but the engine oil is fine and has never been low.

Any ideas?

Sure it wasn't just the water boiling over?

What kind of foam was it?

dunno exactly how to describe it but it was pretty much just white and made up of tiny little bubbles? Like spitting when brushing your teeth kinda thing.

I'd be looking into this fairly cautiously.

Maybe let the car cool, and try to determine if you have oil in coolant, or coolant into oil. Look for emulsified sludge on underside of oil cap, or visible in rocker cover through oil cap opening. Look for rust mark on dipstick, or water/emulsified-oil on dipstick.

If you've topped-up radiator, did it stay full? Check all hoses for leaks or splits, esp those hard to see or obscured by TB/air-intake etc. If cooling and oil services are regular, hose failure may have caused your drama (mum has managed to cook the odd TN and TP with split heater and bypass hoses, over the years).

With car cool, start car and look for bubbles in radiator - tho you will need to wait for thermostat to open and water circulating from block into radiator for this to be a worthwhile check.

Did ticking sound from engine go away, stay? Try to trace where the sound is coming from.

I'd be concerned that you might have done a head or head gasket - combustion gases into coolant or mixing of coolant and oil being the standout suspects for the "foamy" symptom you describe.

If you have a Haynes Manual, or the PDF Mitsi Workshop Manuals - try to look through for "troubleshoot" type chapters which lead you through a diagnostic process.

Best Wishes, don't mean to be all gloom and doom - but would rather you check carefully and minimise further damage. There are much better mechanics than I on these forums, too - hopefully you will get responses from a guru or two!! All best

EDIT: There's no chance your cooling system has been topped-up with a new/different/incompatible coolant or additive recenty??

sorry to say mate i think you have a blown head gasket.

sorry to say mate i think you have a blown head gasket.

In a 3rd gen, its a very hard thing to do (Metal head gasket), usually if the head gasket is blown there is going to be alot more damage and it could require an engine swap... Let it cool down, open the cap and see if there is any oil in there.

Yeah this doesn't sound too good now. If need be I'll just get a second hand engine from a wrecker and possibly go up to a 3.5l one. I'll do the suggested tests in the morning and see how she goes. I forgot to mention in the original post that she died in the drivethrough of KFC last night as well hahahaha and I had to push the bitch all the way around which really sucked. Turned out to just be a dead battery but since then she's been ok.