The heater not heating correctly is generally the first indication that the engine is slightly low on water. I would suspect in your case the engine was more than just slightly low on water.

Some radiator caps are very difficult to get off, the easy way to occassionally check your water level is to look at the plastic expansion tank. When the engine is cool the expansion tank should be nearly full, more tanks are either translucent plastic or they have a translucent plastic window where you can see the water level and there is a level index mark on the side of the tank to indicate if your engine is low.

However, if your engine has lost enough water to cause it to overheat, I would definitely check all the hoses and connections to make sure you do not have a leak.

I had to do something similar once. The car overheated to
the point that the engine died. We coasted off to the side
of the road. Sat there til the engine cooled off. Started
it back up and drove towards home, watching the heat gauge.
It was a wide stretch of road with a wide shoulder to pull off
on when we needed to. So we would get up a lot of speed til
the engine overheated, then turn the key off and coast as far
as we could before pulling over to the side of the road. We
would sit there and let the car cool off then take off again.
We had to do that several times to get all the way home.
Finally got home and let the car sit over night to cool off
completely so we could check it out. It had plenty of coolant.
It was a stuck thermostat causing the problem.
Changed the thermostat and we were good to go.

Pooh Bear

Agree with lzaypup. Before you take it to the local garage for service, check the fluid level. Fill the radiator to the top with pre-mixed coolant.

You probably have a small hose leak that has slowly allowed most of the coolant to escape. If you have a black light, you can check for leaks yourself. Coolant contains phosphorous which glows under black light.

Worst case scenario is a bad head gasket but you'd see a ton of vapor from your exhaust. If your water pump is leaking, you'd see some fluid underneath your car.

I had the same thing happen to me. While the engine was cold, I popped the radiator cap, filled with pre-mixed fluid and started the car. I was able to confirm both the thermostat and water pump worked fine. Before too much pressure builds up in the system but when the temperature rises, you can watch the fluid move through the system via the cap. This is just additional diagnostic info.

Following the uphill with engine running ... and downhill with it not ... made it home without further incident.

I'd had further trouble, in that the warning lights on the dash that turn on when one turns the key on but go off when the car starts ... had been staying one.

And the engine was running much too fast when it was sitting, idling.

On Monday morning, checked oil - O.K., down a little, added some.

Checked coolant, down a little, added some.

Had moved car from garage to by the house ... then it didn't want to start ... after sitting for about an hour, it did.

Stopped at the end of the lane to get the mail, turned engine off - wouldn't start.

Pushed it back up a slight rise in the lane, pushed it down to get started, but not enough speed to start.

Let it sit for a half hour - wouldn't start.

Called CAA ... they said it's be about 45 min, later auto meesage said about an hour, but the tow truck arrived in about 45 min., asked what was wrong, I said starter wouldn't turn engine over. He asked about tapping the starter with a hammer ... but couldn't find it, told me to try to start, I said he should, that I'd tried ...

... so he did ... and it started!

After some colourful language on my part, I told him that I'd be O.K ... and took off immediately, before the engine heated. I thought after I was on the road that I should have asked him whether he'd come from the city, in which case he could follow me down the road that I was going on for about 6 mi., till I turned away from the city, about a half mile from the garage.

More of the operating uphill, not downhill for about 5 miles, till engine began missing some as I was climbing an overpass over a freeway.

So, over the top, I stopped at the side of the road for some recuperative/cooling time - though I hadn't seen the heat gauge rise high, but it rises slowly and I'd been running the engine in short bursts.

Too impatient, I guess (not wanting to sit, doing nothing? maybe should have brought a book?) ...

... after 10 - 15 min., pushed it a bit, it started rolling down the hill, the engine started ...

... but it was still missing ... and after a few hundred feet of travel .. stopped, so I coasted to the side of the road.

Within a mile of the garage, I walked there, they pushed the car in.

It seems that the belt driving the alternator had broken, that produces electricity to replenish the battery's charge. Though it seems that the belts running the water pump, power steering pump, etc. were intact, for some reason the water pump wasn't working ... so, with very little water circulating through the radiator to cool it, the water in the motor heated rapidly. Power brakes and power steering were operating O.K.

Fortunately, they'd replaced my battery last month, so I'd been running on that one battery charge for all of that time. If I'd known of the need, I could have recharged the battery Sat. overnight, at home.

This library closes at 4, so no dice here on Monday, after the garage... and only the downtown London library opens on Monday ... but parking meters near it are rather expensive ... so sometimes I park half a mile away, then walk ... but didn't, yesterday.

However ... I'd made a special call to son on Sat. night, saying that I had pizza ... and would bring it on Sunday ...

... but had forgotten, and had supper with son on Sunday.

So I took the pizza in on Monday and we had pizza for supper; forgetful Dads can be something of a pain.

I'd thought to go to the city library after, but went home instead.

So - it looks as though things are back to normal.

I'm thankful that, most of the time, when I'm in the car ... it's as full of hot air as necessary ... again!

ole joyful

Glad you are no longer hot under the hood!

PoohBear, it's nice to see you here!

Joyful, you and your auto sagas are always entertaining!

If you have plenty of coolant then the overheating is likely
caused by a bad water pump or a bad thermostat.
If you still have problems with the car starting after the
overheating issue it fixed, you may need a starter. As the
engine comes up to temperature the armature in the starter
swells and gets tight inside the case. Makes it hard to turn
the engine to start it. I had that problem once with a truck.

Pooh Bear

Hi Pooh,

It's some chillier here than in TN.

I haven't found out the reason, but it seems that the water pump wasn't operating - though, to hear them tell it, the belt running it was in operation.

Do you figure that I might have been making close to 70 mi. per gallon?

ole joyful