I have a 97 petrol previa auto. Last week it boiled over..never happened before..large whistling sound and water dumped. I waited for it to cool refilled and drove 3 miles home smartish no problem.All was fine for 3 days with short trips. Monday after a 4 mile trip i noticed temp gauge was rising above the normal half way point ut i made it home.After 30 mins i refilled, went for a very short drive and the temp shot up past normal and it boiled over.
All the prophets of doom said head gasket gone £1000 job. But..There is no steam from the exhaust there is no apparent water in the oil or oil in the water. The engine sounds as good as usual.
I changed the thermostat. With the expansion tank cap off I ran the car on tickover for about 15 mins whilst a lot of air bubbled out. By filling it to the brim I see, I think, movement or circulation so I guess the pump is working. I cannot see any turmoil that i have seen in other cars with cracked heads and there is no stream of fine bubbles. The temp gauge sat at mid point all through this test. I blipped the engine a few times which made the water overflow from the expansion tank as it got hotter. Finally the water boiled and overflowed with orrible noises from the hoses and rad.But the temp gauge stayed the same!!
Ok can you guys tell me.
What are the signs for a head gasket gone..
How can you tell if the water pump is working (No bad sounds from it)
Did it boil over because it wasnt pressurised ??
This car has a viscouse fan not electric..any poss problem there?
Any ideas or info most welcome.
This is a classic case where you have a car worth maybe £2500 and facing bills of £1000 plus do you repair it or sell it for breaking and start again. Incidentally they are great cars but very very heavy on fuel but we need an eight seat and such cars are rare.
Cheers