Overheat Protocol?

[osha7677]

Just want to say that since buying a 93 camry with 210K miles a few months ago, this forum is a godsend.

Ok, now for the new problem...

My wife tells me "the car is smoking", so I pop the hood expecting the worst and see coolant all over the front of the engine compartment (whew... was thinking engine was burning).

I ask her if it overheated, and of course she didn't think to look. I ask her if any lights came on and she said she didn't notice any. So I tell her next time she drives it to look at the temp guage and look for any lights. I also told her if it was overheating to pull over and let it cool down before driving it back.

So the next day she comes in the house saying that it is smoking again and that it overheated and the radiator light came on. (of course she drove it home while it was overheating )

No coolant in the resivoer, so I open the radiator and dont' see any coolant in there. I check the oil for tell tail head gasket milk oil and the oil looks fine (thank God).

I look at the hoses for visable cracks and don't see any, of course there is coolant everywhere so it is hard to tell where it was comming from. My GUESS based on the splatter locations is that the cap blew (coolant all over top of radiator, under the hood, and pooled below the radiator).

Two other interesting things... the heater is blowing cold air (i assume this is because the heater core has no coolant) and the radiator fans do not come on.

I bought a new cap, a new thermostat, and rented a pressure tester. Its too cold out right now to mess with it, but thursday it is suppose to get up into the 60's...

Main question I have after all that rambling is this...

If i replace the cap and the thermostat and that does not fix it, AND the pressure tester indicates that I have a seal... what should my next step be? I will probably only have one semi-warm day to mess with this so Im looking for suggestions ahead of time.

[osha7677]

The fans not comming on seems weird to me. What controls when they come on? If it is really cold out will they not come on?

I always thought that overheating due to a fan problem was different from overheating due to coolant loss. Then again, I know little about how the cooling system works...

Is it possiable that the fans were not working which caused the coolant to overheat and blow the cap? It has been freezing tempatures here lately when this started, so I would think the fans would not be nessasary.

[Stillrunning]

Engine?

Your location and time of year may mean the fans don't need to come on. The fans are activated by the coolant temp switch at the bottom of the rad and, I believe, by turning on the A/C. I find the fans come on at idle and/or in traffic when there is not much air flowing thought the rad. If there is no water in the rad then there is nothing to activate the fan switch. I'd check for leaks first with the tester, then check fan operation. If you have an oil cooler check for leaks at the water hoses.

[Kep]

+1 on the temperature switch being inactive with no water.

If your car or truck is working OK, swap cars with your wife until you figure this out. It seems like she is making a bad situation worse. If the car is steaming you may be able to fix it easily. If it is smoking it is getting really hot. Either way, driving with it while overheating will likely damage it. The pressure check will be interesting.

It's too late now, but does your coolant have sufficient anti freeze?

I am not aware of a situation where you could be loosing coolant without a leak and a resulting loss of pressure with a pressure tester. Especially if you are loosing that much coolant in one trip.

Kep

[shocar4]

Originally Posted by osha7677

Just want to say that since buying a 93 camry with 210K miles a few months ago, this forum is a godsend.

Ok, now for the new problem...

My wife tells me "the car is smoking", so I pop the hood expecting the worst and see coolant all over the front of the engine compartment (whew... was thinking engine was burning).

I ask her if it overheated, and of course she didn't think to look. I ask her if any lights came on and she said she didn't notice any. So I tell her next time she drives it to look at the temp guage and look for any lights. I also told her if it was overheating to pull over and let it cool down before driving it back.

So the next day she comes in the house saying that it is smoking again and that it overheated and the radiator light came on. (of course she drove it home while it was overheating )

No coolant in the resivoer, so I open the radiator and dont' see any coolant in there. I check the oil for tell tail head gasket milk oil and the oil looks fine (thank God).

I look at the hoses for visable cracks and don't see any, of course there is coolant everywhere so it is hard to tell where it was comming from. My GUESS based on the splatter locations is that the cap blew (coolant all over top of radiator, under the hood, and pooled below the radiator).

Two other interesting things... the heater is blowing cold air (i assume this is because the heater core has no coolant) and the radiator fans do not come on.

I bought a new cap, a new thermostat, and rented a pressure tester. Its too cold out right now to mess with it, but thursday it is suppose to get up into the 60's...

Main question I have after all that rambling is this...

If i replace the cap and the thermostat and that does not fix it, AND the pressure tester indicates that I have a seal... what should my next step be? I will probably only have one semi-warm day to mess with this so Im looking for suggestions ahead of time.

any update on this situation! my brother's 93 is doing the same thing! no heat, overheating almost immediately! the water pump only has 20k on it and he replaced the thermo, but nothing! could the heater core be clogged???

[Dave's]

A clogged heater core can result in no cabin heat but should not cause the engine to over-heat. I suspect you both need to check the coolant mix. If it's wrong in either direction (too much or too little anti-freeze mixed in with the water) then it may be turning to slush and not cooling properly. If that's ok then, with the engine cool, remove the radiator cap (not the reservoir cap) and start the engine in park/nuetral. Check that the coolant begins to flow and increase noticably in the rad within 10-15 minutes or so. (good time to check those fans too - don't touch them! they can start at anytime.) If not then the t-stat could be stuck shut or the pump's bad. That's where I would start. I'm sure others can give you other ideas as well.

[haskandine]

ok, first thing i clean off all the coolant that was spilled with a water hose. next fill up the radiator with coolant, i prefer toyota red coolant because when it leaks it drys and turns red. which makes it easier to see a coolant leak. next look for any coolant leaks from the top of the radiator. when the plastic on top gets old it cracks. ive seen so many toyota radiators do this. next, i would pressure test the coolant system. when you apply pressure look for any visual leaks. if it is holding pressure then i would say it might the thermosat.

[shocar4]

Originally Posted by haskandine

ok, first thing i clean off all the coolant that was spilled with a water hose. next fill up the radiator with coolant, i prefer toyota red coolant because when it leaks it drys and turns red. which makes it easier to see a coolant leak. next look for any coolant leaks from the top of the radiator. when the plastic on top gets old it cracks. ive seen so many toyota radiators do this. next, i would pressure test the coolant system. when you apply pressure look for any visual leaks. if it is holding pressure then i would say it might the thermosat.

we dried the coolant and replaced the thermostat and after about 3 minutes of the car running the temp climbed to the red zone! water pump is only 20k miles old and i can't hear any noise coming from it, but it acts like the coolant isn't getting circulated through the car! no heat...no fans running, but it is in the teens here right now!

[Kep]

shocar4 - did this start happening before or after replacing the thermostat. When you drain and refill the system t is not unusual for an air bubble to collect at the thermostat and then the thermostat (even a new one) can't open and the coolant can’t circulate. Some more expensive thermostats have a little air passage at the top to allow the air on through.

If this is your problem, a cheap alternative is to drill a small hole in the thermostat's flange where it will be at the top of the housing so the air can pass through to the radiator. Do some searches, there were a couple of posts on this.

Some other folks park the car on a steep incline or hop a curb and get the air out that way. I believe that there is a relief fitting that can be unscrewed also but I don’t know where it is on the engine.

Kep