Cooling problem, Camry V6 -95

[bgkiller]

Hi all Camry-experts!
The last week I have had temperature problems with my Camry V6 1995.
Symptoms are these

- Engine occasionally runs very hot. This can happen both when running and standing still. However, temperature control can work perfect for 50 miles before the problems start.
- When the engine goes hot. I don't get the heating to work, only cold air out of the fan.
- At two occasions coolant has started boiling in the expansion tank.

So far done

- replaced thermostat

To me it seams that something stops the flow of coolant. Are there other suspects than the water pump now? Can a water pump fail in such a way that it works intermittently? Is there some other valve or something that can close the water circuit?

From quickly browsing the forum it seams that others have run in to very similar problems, but I didn't manage to find a good conclusion.

Ideas?

Regards,
Johan (Toyota Camry owner in Sweden)

[deancass2000]

Originally Posted by bgkiller

Hi all Camry-experts!
The last week I have had temperature problems with my Camry V6 1995.
Symptoms are these

- Engine occasionally runs very hot. This can happen both when running and standing still. However, temperature control can work perfect for 50 miles before the problems start.
- When the engine goes hot. I don't get the heating to work, only cold air out of the fan.
- At two occasions coolant has started boiling in the expansion tank.

So far done

- replaced thermostat

To me it seams that something stops the flow of coolant. Are there other suspects than the water pump now? Can a water pump fail in such a way that it works intermittently? Is there some other valve or something that can close the water circuit?

From quickly browsing the forum it seams that others have run in to very similar problems, but I didn't manage to find a good conclusion.

Ideas?

Regards,
Johan (Toyota Camry owner in Sweden)

I would check these things out in this sequence:

Run the car to operating temperature

Feel with your hand, the top hose and then the bottom hose. Are they both hot or is the bottom hose colder than the other, by colder I mean a lot colder.

If they both feel the same or roughly the same, check your coolant level first. If the coolant level is OK I would then pull out the thermostat, refill any lost fluid (probably with just water until you get it fixed) and then run the car without the thermostat. If it seems to stay cool with the thermostat out and is not overheating, then the thermostat needs replaced. If you still have the overheating with the thermostat out, continue reading.

Remove the bottom hose on the waterpump side from the waterpump gooseneck. Remove the top radiator hose from the radiator. Start the car and stick a waterhose in the gooseneck side of the waterpump. Do you have coolant flowing out from the other side's hose that is disconnected from the radiator? If so, then your waterpump is probably working, if not, then your waterpump is probably bad. Just to doublecheck, have someone rev the engine, the waterflow should increase with the engine rpms. If it doesn't increase with the rpms then your pump is probably bad.

If you are getting good coolant flow and the thermostat is out or has been replaced, are your cooling fans kicking on before the temp guage makes it's way to the top? This is easy enough to check. Are they? If not, then you have a problem with your coolant heat sensor in the bottom of the radiator or a fan relay. If the fans are kicking on and you are still overheating after checking all of the above.......it might very well be a head gasket.

I would keep in mind that when you are taking off and putting things back together to remember to fill the block with water from the high hose side, this helps in priming the waterpump...........hope this helps!

[toyomoho]

The pump blades can break off and even lodge in the cooling system, the result is over heating or strange coolant behavior.

Possible for the bottom hose on the radiator to collapse internally from suction of the pump cutting off coolant flow.

Suggest trying to back flush the coolant system with a garden hose.

[bgkiller]

All parts were ok in the cooling system

- thermostat ok
- pump ok
- flow ok (at least when system only contains water)

It must then be head gasket(?) .

- I see no water in the oil (oil is still as new after many miles with this problem)
- I see no white smoke from the car

Could it be "combusted air" that leaks over to the cooling system and pushing the water to the expansion tank. After some time the system contains too little water to get flow and working cooling, which results in overheating starting.

To repair the head gasket would be a too expensive treatment for my Camry V6 -95 (186 kmiles).
Now, I need to drive it until I find a new car. I see two options. Which would you experts say have best reliability, driving experience etc.

1) Keep on as I do now. Fill with water before every driving. Only drive short distances. Always keep an eye on the temperature meter. Carry water onboard to use if overheating occours.

2) More inventive approach. Close the outlet to the expansion tank. This will make the car have a closed system for cooling water. Water can not escape to the expansion tank, which I believe is my problem. Is there a risk that I get a too high pressure in the cooling system? Will I push water into other parts of the engine?

All thoughts are welcome!

Regards,
Johan

[J_Phu]

With minor head gasket damage you can try using some head gasket repair. It'll last you for some months, did it to my car and been running good ever since. It could even take some redlinning once in a while, and no I did't blew my head gasket redlining it was bad old reused head bolt.