Car Over Heating??? Help Needed

[Mike.C]

I know that this sounds like the 'How long is a bit of string' question, but here goes anyway.

How hot are the rubber pipes supposed to get in a cars cooling system? Just by chance I happened to touch one of the rubber hose's on my wife's Vauxhall Astra, and it was so hot that I could not keep hold of it. The only problem I have had with the cooling system was a couple of months ago when I noticed that the fan was not coming on, and in the end I traced it to the radiator thermal switch, which I changed.

Except for the extremely hot pipes there is there are no other symptoms of over heating. The gauge on the dash reads normal. The expansion tank shows that I have used about a cup of water since I renewed the anti freeze when I changed the above switch. There is no mayonnaise type gunge which happens when oil and water mixes. There is no loss of power.

Oh yes I also changed the thermostat when I changed the above.

So should the rubber pipes get this hot?

Cheers

Mike

 

[Dibs-h]

I know that this sounds like the 'How long is a bit of string' question, but here goes anyway.

How hot are the rubber pipes supposed to get in a cars cooling system? Just by chance I happened to touch one of the rubber hose's on my wife's Vauxhall Astra, and it was so hot that I could not keep hold of it. The only problem I have had with the cooling system was a couple of months ago when I noticed that the fan was not coming on, and in the end I traced it to the radiator thermal switch, which I changed.

Except for the extremely hot pipes there is there are no other symptoms of over heating. The gauge on the dash reads normal. The expansion tank shows that I have used about a cup of water since I renewed the anti freeze when I changed the above switch. There is no mayonnaise type gunge which happens when oil and water mixes. There is no loss of power.

Oh yes I also changed the thermostat when I changed the above.

So should the rubber pipes get this hot?

Cheers

Mike

I don't think there's anything wrong with your car Mike. Coolant (aka antifreeze) also raises the boiling point of the water in the system and has corrosion inhibitors - it isn't all about "anti freeze". As long as the gauge is operational and sat where it is supposed to - no issues. You aren't supposed to be able to hold the rubber coolant pipes when the engine is up to temp.

HIH

Dibs

p.s. A little bit of coolant "lost" every now and then is no big issue - especially as everything else looks fine and it's about a cup worth.

 

[Noel]

Hot (but not too hot) pipes taking the hot water back to the rad are ok. When the engine is still warm take the cap off the expansion tank (carefully with a rag) and have a sniff, if there's that "overheating" pong you may have an issue. Could be a brown gunge partial blockage somewhere. Did you give the system a good flush when you renewed the AF?
Noticed any decrease in MPG?

 

[Mike.C]

I know that this sounds like the 'How long is a bit of string' question, but here goes anyway.

How hot are the rubber pipes supposed to get in a cars cooling system? Just by chance I happened to touch one of the rubber hose's on my wife's Vauxhall Astra, and it was so hot that I could not keep hold of it. The only problem I have had with the cooling system was a couple of months ago when I noticed that the fan was not coming on, and in the end I traced it to the radiator thermal switch, which I changed.

Except for the extremely hot pipes there is there are no other symptoms of over heating. The gauge on the dash reads normal. The expansion tank shows that I have used about a cup of water since I renewed the anti freeze when I changed the above switch. There is no mayonnaise type gunge which happens when oil and water mixes. There is no loss of power.

Oh yes I also changed the thermostat when I changed the above.

So should the rubber pipes get this hot?

Cheers

Mike

I don't think there's anything wrong with your car Mike. Coolant (aka antifreeze) also raises the boiling point of the water in the system and has corrosion inhibitors - it isn't all about "anti freeze". As long as the gauge is operational and sat where it is supposed to - no issues. You aren't supposed to be able to hold the rubber coolant pipes when the engine is up to temp.

HIH

Dibs

p.s. A little bit of coolant "lost" every now and then is no big issue - especially as everything else looks fine and it's about a cup worth.

Many thanks for your quick reply Dib's. I did forget to say that in between services it does not use/lose any coolant at all. The expansion tank is filled to the maximum mark, and that's where it stays, except on this occasion.

Noel wrote;

Hot (but not too hot) pipes taking the hot water back to the rad are ok. When the engine is still warm take the cap off the expansion tank (carefully with a rag) and have a sniff, if there's that "overheating" pong you may have an issue. Could be a brown gunge partial blockage somewhere. Did you give the system a good flush when you renewed the AF?
Noticed any decrease in MPG?

The pipe coming out of the bottom of the radiator is just as hot as the one going into the top.

I just tried the sniff test and to be perfectly honest I THINK???? it smells the same as usual :roll:
There is defiantly no brown gunge, it is it's normal sky blue.

Yes I did flush the system before I added the new anti freeze.

I have not noticed any decrease in the MPG.

Cheers

Mike

 

[Dibs-h]

Just keep an eye on the gauge and coolant levels for peace of mind - but I do not believe your car is over heating.

Dibs

 

[Mike.C]

Thanks to you both, I will keep an eye on it.

Cheers

Mike

 

[greybeard]

Physics never was a strong point of mine.....but I seem to recall that some car cooling systems may be pressurised up to 2 atmospheres? Or sometimes more? All in the interest of maintaining a suitably hot operating environment.....Or is that complete wossnames?

Whichever/whatever - any increase in system pressure raises the boiling point, and therefore the effective operating temperature...which I always understood to be a good thing. So ditto for the pipework etc......?
Too hot to touch/hold is nowhere near BP I suspect?

I know, I know - more questions than answers!

 

[misterfish]

Sounds perfectly normal to me. If the temperature gauge shows normal and doesn't fluctuate all the time then it sounds OK.

The water in the cooling system does get hot - you should always be very careful undoing the radiator cap when the system is hot as the release of pressure can allow the coolant to boil over. If I remember rightly the temperature that the thermostat opens to allow the coolant to flow into the radiator is around 90 degrees C, so it will feel hot.

Misterfish

 

[Ironballs]

The fans in many cars are triggered to kick in at 80-90C, if you can hold a hose with 85C water in it you're a tougher man than me and can do/say just about whatever you jolly well like!

My Trevor has a digital dash and readouts for oil and water temps, I've seen the water get up to the early 90s in traffic and summer heat

 

[Shane]

The fans in many cars are triggered to kick in at 80-90C, if you can hold a hose with 85C water in it you're a tougher man than me and can do/say just about whatever you jolly well like!

exactly

safe working temperature for an engine is between 80-95c, much less and the oil is to cold to work properly, much hotter and the oil will start to break down, if you can hold a water pipe in that heat range you is well'ard

 

[webriq]

that was the problem with me also looking for some good suggestions what to do

 

[Digit]

As was pointed out by greybeard Mike the pressure cap raises the boiling point of the coolant so yes, the pipes do get bloody hot.

Roy.

 

[Mike.C]

As was pointed out by greybeard Mike the pressure cap raises the boiling point of the coolant so yes, the pipes do get bloody hot.

Roy.

Thanks everyone I believe you. It was just that for the first time between services it had used some water and I cannot remember the pipes being that hot, but on the other hand I have never worked on the car straight after a long run, which was when I felt the pipe.

Mind you I am still well'ard :roll:

Cheers

Mike

 

[Ironballs]

I've had a leaky seal on the cap before Mike and with the heat and pressure it was enough to lose quite a startling amount of water over a few months - when the garage pointed it out

 

[Mike.C]

I've had a leaky seal on the cap before Mike and with the heat and pressure it was enough to lose quite a startling amount of water over a few months - when the garage pointed it out

Thanks mate I will keep an eye on that too.

Cheers

Mike