Hello,
Disaster happen last weekend and I need help.
I'll try my best to explain but pardon my English.

Was driving on highway at night, suddenly all instrument lights up and lost power steering.
Then engine temp started rising, overheat warning light came up.
I was on a highway without shoulder so had to push driving till next exit without stopping car. Probably I drove few miles with overheat….damn.

Anyway right after exit, parked car immediately and opened hood. I see my coolant boiled, white smoke all over.
It was after 11pm so couldn't see much in the dark. Called towing and now car is in my garage.

I checked the car last weekend and see my belt is gone. I think I read about somewhere about weak idler pulley so checked two pulley first.
One looks good but the other one that located closer to front radiator is very loose, just dangling around.

So first questions are,

Can this blow my head gasket? Or probably engine usually hold few miles with high temperature?
If it's not engine, what are the thing I need to check for leaking coolant after overheat?

Last, idler pulley. How easy it is to change? Just un-bolt and put new one in? Should I just use same OEM pulley?

Thanks.

 

Ouch. Since the SC is connected to the water pump, it would make sense that it overheated. There is definitely a risk of a blown gasket, but that can be checked with compression/leakdown tests if there are no outward signs of it having blown.
Be sure to check your crank pulley, as they have been known to be damaged by the tensioner pulley when the belt breaks.

 

how crank pulley damaged by the tensioner pulley? Just trying to understand here. Also how to check crank pulley is good or bad?

By the way when overheat the coolant after SC/water pump not spinning by belt is off, does coolant hoses gets busted first? or head gasket? generally speaking......

Thanks for much for post.

 

The tensioner pulley can over-extend and contact the crank pulley, thus marring/denting or otherwise damaging it. Haven't seen it in practice, but if it looks 'whole' - i.e. undamaged, it should be ok. You should also be able to crank the engine over and see if it runs true.

As for overheating, the first point of failure, it really depends. Could be a hose, the fill/overflow tank, or any point in between. In my history, clouds of smoke is more indicative of a hose, rad cap or water pump weep hole (of course, the last two do not apply to the MCS) than a head gasket - head gaskets tend to weep one way or the other (into or out of the cylinder) vs. going up in smoke. I just had a head gasket go on our Subaru, and it boiled over through the cap/overflow tank.