Cooling problems

[Psirus]

Hello,
my car has sort of broken down on me.
I was cruising along the motorway, when the cooling warning light came on.
Yet the water temperature was fine.
Unable to do much about it, I drive until the next town (20-25km).
Along the way, I noticed a very unhealthy sound from the engine bay.
Also, the heater stopped working, it would still blow some air, but that was very cold.
In that town, I opened the bonnet and noticed that there was no coolant whatsoever left, so I poured a bottle of mineral water into it...don't know if that was such a good idea.
Drove the last 20km very easy on the engine, and now parked it in front of a garage, will talk to the guy tomorrow.
Any ideas what it might be, and how much I'm likely to spend?

[Spectre]

Um.... You may have very severely damaged the engine.

[Psirus]

Could you be a bit more specific?

[narf]

Originally Posted by Spectre

Um.... You may have very severely damaged the engine.

No heat from the heater is a pretty bad sign because it gets its heat from the cooling system. Just like with an outboard motor, if you let it wee the expelled water onto your hand and it feels cold you have a problem.

Indicated fine water temperature may be pointless if there is no water to measure the temperature of

Usually a warning light (oil, cooling and the like) is the engine screaming for help, asking to stop immediately. While you may be lucky and everything may be fine, running an engine without coolant is like running your CPU with a small heatsink and turning off the fan. Will work for a bit, will start to scream for help soon, will die a while after.

[rowd22]

Originally Posted by Spectre

Um.... You may have very severely damaged the engine.

Yes, you could have.
If there's no coolant to cool it, the whole engine will expand, (albeit slightly) because metal expands when heated. This could be causing the unusual sounds you heard - maybe knocking or thumping sounds???

Then again, you may be lucky and the damage is minimal - just need more coolant

[Nabster]

Generally by the time the oil or coolant lights come on, if you don't stop and turn it off right there you'll dig yourself into trouble. Mineral water was not the best choice, but in your situation probably the right thing to do, though it won't have helped much. Your cost could be as simple as a replacement hose for one that failed plus the cost of refilling the cooling system, or as much as a new engine. With what you gave us, it's rather hard to get very specific.

[_HighVoltage_]

The Polo engine is a tough little engine. But even so, running it without coolant can be fatal.
You could have a cracked radiator and all your coolant may have leaked out. If it was just a hose, you probably would've noticed it.

[Dr_Grip]

The best thing you can do at this point is trying to find out where the coolant went, fix the leak (new hose/radiator/whatever), replace the coolant and hope the engine starts and runs normally.

If not, check back with us for more ideas

[VR6]

Do you have a coolant leak? Or plumes of white smoke coming out the back?

[argatoga]

Originally Posted by VR6

Do you have a coolant leak? Or plumes of white smoke coming out the back?

It looks like he had no coolant at all.

[VR6]

Originally Posted by argatoga

It looks like he had no coolant at all.

I was wondering how it got out in the first place.

[Polygon]

Well, coolant gets out a couple of different ways.

1. Leaks: It can leak from various places like a hose, the radiator, the heater core, or the water pump itself. You can check for for these pretty easy. Fill the system and check for the leak. Now, if it's the heater core it will fog up your windshield.

2. Combustion: This happens when you have a leak that allows the coolant to get into the combustion chamber. This can happen because of a blown head gasket, a cracked/warped block or head, or a cracked sleeve/rings. To check for this there are a few ways and that would be a sweet smell in the exhaust usually paired with white steam. Do a leak down test. If you hear bubbles then you have a leak at the engine. You can also have the coolant checked for hydrocarbons.

Now, this all being said. The reason your light came on but temp stayed normal is because the light told you that you needed coolant. The temp was fine because there was no coolant around the sensor to measure the temp so it was just measuring the temp of the air. The damage you may have cause would be warping or cracking the head/block. If you warped them that can be fixed. If they've been cracked you'll need to replace them. If you're really lucky then you might just need to do the head gasket(s).

When you find that you're coolant light comes on and/or you're over heating then pull over ASAP and shut off the car and let it cool down. Once it's cooled down then you can add water but never add water to the system when it's still hot.