Is it high enough to do damage? It's for a mate who's just blown his Porsche's radiator out in Italy.... he thinks he's on his way to a radiator repair place, but not entirely sure as the recovery truck driver doesn't speak a word of English!

 

That's pretty hot, yes. Water shouldn't get over 100, or even near it, ideally.

 

thats not true... engine coolant will go above 100, the system is pressurised which increases the boiling point and the chemicals in the anti-freeze/coolant also allow the water in the system to rise above 100 without it boiling

You probably wouldnt see over 100 in the rad but in the water ways around the cylinders over 100 is probably normal...depend where you take the reading from.

Gaz

 

The Wife's SLK said in the instructions that it could run upto 120 C without problems!

 

According to google, the water will boil at about 115 degrees

 

If you go on how stuff works and look up car cooling systems it will give you more info... With the correct amount of chemical in it the water should be ok up to around 120-135 C then you have the addition of the pressureised system which will prevent boiling further.

However if the car runs at say 90 C on the gauge which will have the sender unit placed in a fairly hot place but not at the hottest part (hottest part being around the cylinders, exhaust ports etc) and the gauge has increased 30 C then it would have increased quite alot around the hottest parts of the engine which could be enough to boil it in thoes parts of the engine.

It probably wouldnt have done any damage if it was only run for a short while and wasnt thrashed when it was running. Running an engine too hot could warp the heads, cause the oil to break down so it wouldnt lubricate properly and could cause the engine to seize by welding the pistons to the bores.