[UvjqTVVC]

I know there are a few mechanicy types on here, who will hopefully have been drawn out of hiding by ace_rimmer's post, so here's my problem: overheating!

It's only been the last couple of days or so, but after driving for only 10 minutes or so, my temperature guage goes right up to between 75% and 100%. It normally stays there, but today after I went through the McDonald's drive through and had to turn the engine off and back on, it went right up to 100% and my big red "STOP" light came on. When I drive slowly, like through towns, it seems to cool down a bit, and when I was going down a big hill with my foot entirely off the accelerator the warning light went off and it cooled down a fair bit.

I checked my water level yesterday (the tube next to the radiator) and it was pretty much empty, so I filled it back up with water (apparently I should have used anti-freeze. Oops!). That didn't seem to make any difference. From reading into it it seems that maybe the thermostat is at fault. Does that sound about right? I suppose I'll have to take it to the garage to get it fixed, just wondering if the symptoms seem exactly like anything anyone's heard of or experienced. Ta!

[Intockatt]

Pop off the cap to the radiator while the car has been off for awhile. If you checked the reservoir, that doesn't matter if it is empty of filled to the top.

If the radiator is empty, or not filled up to at least near the top, fill it up with water, run your car for a while and see if there are any leaks. Then fix what is leaking. Straight up water is fine for this test.

If your radiator is full of liquid, then it could be something else like the water pump. Thermostat kicks in to tell the pump to start pushing the water through the motor, and may not be kicking it to do so.

Water in a radiator is fine anyways. You usually have a 50/50 ratio for antifreeze and water, but it is ok to have a little higher water mix, at least in the summer time.

[oscilsoda]

Some things to check for:

Fill the radiator and run the engine for a good 20 mins, then check both radiator hoses and make sure they are hot.

If they are both getting warm....

Check for white smoke from the exhaust, or water spitting out of the pipe.

Check your oil level

Check your oil cap, make sure there is no whitish milky film around the lip

Check your coolant and make sure there is no film floating on the surface

These are possible signs of a leaking head gasket

[Emalodoulouts]

bah I should read all the post before relying.

take it to a garage and have it checked over for overheating damage.

[UvjqTVVC]

I did notice that the oil level was low when I checked the water yesterday. I refilled both and had high hopes that that would solve the problem, but unless they needed a while to work through the system or whatever, they haven't. I have noticed a leak of some kind under my car in the past while, but assumed it was oil.

Some good tips there though, many thanks. I'll make sure and check them out if and when I get home after work [surrender]

bah I should read all the post before relying.

take it to a garage and have it checked over for overheating damage.

Yes, I hear there's some pipe or something you can warp with overheating that can make the whole thing become very expensive. I'm hoping it's nothing like that.

[Emalodoulouts]

I did notice that the oil level was low when I checked the water yesterday. I refilled both and had high hopes that that would solve the problem, but unless they needed a while to work through the system or whatever, they haven't. I have noticed a leak of some kind under my car in the past while, but assumed it was oil.

Some good tips there though, many thanks. I'll make sure and check them out if and when I get home after work [surrender]



Yes, I hear there's some pipe or something you can warp with overheating that can make the whole thing become very expensive. I'm hoping it's nothing like that.

not only pipes me ole muckler

[Konservir]

When the engine is warm/hot you should have the engine running if you want to add more water. If you fail to do so you risk for cracking the head.

What sort of car do you have?

[Intockatt]

When the engine is warm/hot you should have the engine running if you want to add more water. If you fail to do so you risk for cracking the head.

What sort of car do you have?

Are you saying while the motor is hot like when its above normal operating conditions. If you pop open the radiator while its operating and the engine has heated up, pressure builds in the system. Once you pop that radiator cap you are really going to get burnt. Then pouring water into a very hot system wont be good either.

Much safer for the user to just pour water in while the engine is off, or has just been turned on to heat the motor up to get the water pump cranking if it still works.


Just hope that your gaskets are fine. If not, water and oil can have gone places they are not suppose to go. Our Honda blew a head gasket and we had to not only replace that but get a new
radiator (very pricey items), water pump, oil pump, and hoses. Should have also replaced the heater core (another very pricey item) but oh well.
Basically oil and water mix throughout the entire system instead of staying separate like they are supposed to.

[pongeystrhjst]

From reading into it it seems that maybe the thermostat is at fault. Does that sound about right?

That was my initial thought.
And if it is just the thermostat, then it should be a very easy (and cheap) fix.

[Slchtjgb]

There is also the probability that the electric fan isn't operating. If it was a blocked/stuck thermostat it wouldn't cool off when driven at higher speeds.

[GillTeepbew]

There is also the probability that the electric fan isn't operating. If it was a blocked/stuck thermostat it wouldn't cool off when driven at higher speeds.

Agreed for the most part.

If the engine is cooling off to normal temperatures while driving at high speeds, then it's not the thermostat. Because obviously it is open and water is flowing. But it never hurts to change it out anyways. Usually cheap to do and very easy to do yourself. Quick question tho. How long does it take your car to heat up? if the thermostat is stuck open, it should take your car much longer to heat up.

And to check Gordo's suggestion. Park your car and pop the hood while letting it idle and heat up. Check your water temps and check to see if your fans kick on. Just keep your fingers clear.

And it is normal for a cars water to heat up while the engine is off. That's because while the engine is off, the water pump is not working. The water sits inside the engine absorbing more heat out of the block before everything will start to cool back down.

[Konservir]

Are you saying while the motor is hot like when its above normal operating conditions. If you pop open the radiator while its operating and the engine has heated up, pressure builds in the system. Once you pop that radiator cap you are really going to get burnt. Then pouring water into a very hot system wont be good either.

Much safer for the user to just pour water in while the engine is off, or has just been turned on to heat the motor up to get the water pump cranking if it still works. If the engine has overheated you're going to get severely burned if you open the cap whether the engine is running or not.

You let cool the engine a bit. With a cloth folded several times you turn the cap just a bit while your arm is extended. IF there's steam release, screw back the cap, then unscrew it again. Do this operation until there's no more steam, and then you can fully open the cap. Turn on the engine. With the engine running add anti freeze/water.

I wouldn't advise to anyone to add water when the engine switched off while it is warm/hot. You risk of cracking the head!

[Konservir]

Still need to know what car is it.

[Theariwinna]

Sounds like maybe you have a radiator fan and it isn't cutting on.

If there's a fan on the radiator, start the car up and check and see if it's spinning.

[pongeystrhjst]

If the engine is cooling off to normal temperatures while driving at high speeds, then it's not the thermostat. Because obviously it is open and water is flowing.

If the engine is cooling off while driving at speed it's because there is airflow.
Air cooling is plenty sufficient to keep an engine cool.

The indicator, to me, that it's the thermostat is that it overheats while not moving or moving slowly.

[Slchtjgb]

If the engine is cooling off while driving at speed it's because there is airflow.
Air cooling is plenty sufficient to keep an engine cool.

The indicator, to me, that it's the thermostat is that it overheats while not moving or moving slowly.

Haha - no!

[Theariwinna]

If the engine is cooling off while driving at speed it's because there is airflow.
Air cooling is plenty sufficient to keep an engine cool.

The indicator, to me, that it's the thermostat is that it overheats while not moving or moving slowly.

Revving up an engine to increase the speed will NEVER cool it down. You might as well speed up when you're low on gas so you get there quickly, before you run out!

The reason why it's cooling off when you are coasting down a hill is because you're increasing speed(in return, airflow) without heating up the engine.

[UvjqTVVC]

It's a peugeot 306 I have, and I'm fairly sure the radiator fan isn't coming on, since you can't hear it at all, like I could on a previous 306 I had. Though I've never heard it, so I'm sure there's something else going on there as well.

It takes about 5 minutes or so before the temperature guage goes all the way up, so it's not going to be that it takes overly long to heat up.
When I was giong down the hill, the temperature didn't return to normal levels, just low enough that my warning light went out.

I have my car booked in to the garage on Monday, so I guess I'll see what's going on there, fingers crossed it's nothing too expensive.

Ta again for the tips/advice folks!

[Theariwinna]

It's a peugeot 306 I have, and I'm fairly sure the radiator fan isn't coming on, since you can't hear it at all, like I could on a previous 306 I had. Though I've never heard it, so I'm sure there's something else going on there as well.

It takes about 5 minutes or so before the temperature guage goes all the way up, so it's not going to be that it takes overly long to heat up.
When I was giong down the hill, the temperature didn't return to normal levels, just low enough that my warning light went out.

I have my car booked in to the garage on Monday, so I guess I'll see what's going on there, fingers crossed it's nothing too expensive.

Ta again for the tips/advice folks!

Just pop the hood and crank it up to see if the fan comes on. If not, that sounds like your problem. Might just be a fuse that you can replace yourself.

[Konservir]

Does it have an a/c? If yes turn on the a/c and it should turn on the fan. It happened to me in my sisters golf 3. The cooling fan wasn't turning on so I turned on the a/c, which turned on the fan so I could drive till I had it repaired (faulty temp switch).

If you don't have a/c but want to make sure that the fan is at fault, turn on the engine, let it heat, the turn on the heater inside the car at full power. This should cool the car down (It's going to be pretty warm inside though).