Please help - Car Overheating!

BTTB said:
The cap on the water bottle is often overlooked when it comes to overheating.

Let the car idle until engine is hot and the fan kicks in, at the same time watch the water level in the bottle, it is rises, then the cap is the wrong size and/or not sealing properly.
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ChilliGirl said:
have you checked the thermostat???
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yeah fan switch and thermostat ....

get it done quick ...i left mine tooo late and blew the gasket
 
Gnome said:
Yeah wasn't really disputing what you said, I should have said added that the fact that there is no anti-freeze isn't the reason his car is overheating/boiling/etc.

It may have been caused by the lack of anti-freeze (IE. corrosion, I've seen plenty of 1998 model Corsa's that have never had coolant changes, the water literally looks like liquid rust) but adding anti-freeze isn't going to solve it, the damage is already done.

Delta didn't have a change interval for coolant on the Corsa, GM has subsequently set it at every 4 years, so I suspect the fact that so many Corsa's are driving around with rust colour anti-freeze that hasn't been changed since day 1 might have something to do with the high rate of thermostat failure.
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I have always run my cars on pure anti-freeze for a few reasons. The two main ones are as follows:
Does not keep the temperature down but does prevent things getting under pressure (as it has a higher boiling point).
Stops rust and gunk.
 
AstroTurf said:
I have always run my cars on pure anti-freeze for a few reasons. The two main ones are as follows:
Does not keep the temperature down but does prevent things getting under pressure (as it has a higher boiling point).
Stops rust and gunk.
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Very bad idea. Antifreeze has a much lower heat capacity than water, which means that it's more likely to boil, and thus provides worse cooling. Stick to manufacturer's mixture recommendations.
 
Claymore said:
Very bad idea. Antifreeze has a much lower heat capacity than water, which means that it's more likely to boil, and thus provides worse cooling. Stick to manufacturer's mixture recommendations.
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You have that the wrong way around buddy.
 
Jhercules said:
Hi guys. Don't want to hijack the thread, but I am having this exact problem with my Opel corsa since Monday. The car however doesn't get hot as long as it's moving. It's only when I have to sit and idle in traffic. Does that point to a specific problem? The water was boiling when I opened the bonnet yesterday. Checked oil and water - everything seems fine.
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Your radiator fans are not working. Check fuses, relays, fan motors and temperature switches/senders.

If you want to know whether it's thermostat, just feel the hose going from the top of your engine to your radiator. If it's very hot, your thermostat is most likely NOT stuck closed. (They are designed to fail open).
If the top hose is very hot, feel the bottom hose. If it's cold, it's likely you have a blocked radiator core.
 
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Jhercules said:
Hi guys. Don't want to hijack the thread, but I am having this exact problem with my Opel corsa since Monday. The car however doesn't get hot as long as it's moving. It's only when I have to sit and idle in traffic. Does that point to a specific problem? The water was boiling when I opened the bonnet yesterday. Checked oil and water - everything seems fine.
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definitely sounds like the fan
 
Claymore said:
Very bad idea. Antifreeze has a much lower heat capacity than water, which means that it's more likely to boil, and thus provides worse cooling. Stick to manufacturer's mixture recommendations.
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Isn't it amazing how one person can always get it wrong!!? :rolleyes:

There is nothing wrong with running on pure antifreeze, and your car will thank you for it. Our rally car never saw water added to the antifreeze and we never had an overheating problem after thousands of kilometers of extreme driving.

Astroturf is correct!!
 
The way I see it is antifreeze only benefits you wrt corosion & lubrication (assuming you live in a place where it does not get cold enough for water to freeze). Pure water will run a few degrees cooler than pure antifreeze but pure antifreeze also wont make the temps shoot through the roof and seize your engine.

People running rotax engines for light aircraft for example can see noticeable differences in engine temps based on how much antifreeze they use but then again they have pretty small radiators as well.

http://en.wikipedia.org/wiki/Ethylene_glycol#Coolant_and_heat_transfer_agent
Pure ethylene glycol has a specific heat capacity about one half that of water. So, while providing freeze protection and an increased boiling point, ethylene glycol lowers the specific heat capacity of water mixtures relative to pure water. A 50/50 mix by mass has a specific heat capacity of about 0.75 BTU/lb F, thus requiring increased flow rates in same system comparisons with water. Additionally, the increase in boiling point over pure water inhibits nucleate boiling on heat transfer surfaces thus reducing heat transfer efficiency in some cases, such as gasoline engine cylinder walls. Therefore, pure ethylene glycol should not be used as an engine coolant in most cases.
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Never seen anyone selling pure ethylene glycol as antifreeze.
 
Fazda said:
Isn't it amazing how one person can always get it wrong!!? :rolleyes:

There is nothing wrong with running on pure antifreeze, and your car will thank you for it. Our rally car never saw water added to the antifreeze and we never had an overheating problem after thousands of kilometers of extreme driving.

Astroturf is correct!!
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Your personal anecdotes do not trump scientific facts, I'm afraid, as Ponder pointed out. Otherwise manufacturers would run purte antifreeze instead of a mix, would they not?
 
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