Overheating (1 Viewer)

[Boo]

Hi again all oldies and newbes,

Finally got membership :thumb: *grrrrrr paypal*

Since I topped my radiator up with water it has decided to throw all the coolent out and temp gauge goes up to 220 degres ( hope that is C and not F))

Should I have use special coolant?


Cheers in advance

Boo

 

[blamehofman]

 

[Boo]

means? lol!

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[jezport]

You dont say what vehicle or engine so it is hard to help

 

[Boo]

Sorry, was having a moment there.....its a 7.4 Vortec Chevy V8.

Boo

 

[jezport]

Sorry, was having a moment there.....its a 7.4 Vortec Chevy V8.

Boo

You need to speak to Duncan at Star Spangled Spanner. http://www.starspangledspanner.com/shop/index.php
He is a top bloke and will give you good advice as he is also a mechanic with over 30 years experience.

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[BobProperty]

Since I topped my radiator up with water it has decided to throw all the coolent out and temp gauge goes up to 220 degres ( hope that is C and not F))

Er, first, I think you mean the other way round. 220C and various bits under the bonnet will have melted. 220F is about 104C which agreed is too hot for an engine coolant temperature. Coolant additive won't make too much difference but something is wrong beyond just that. Please let us know what vehicle and engine you have (guessing RV given that then temp gauge is in F.)

 

[BobProperty]

Cross posting for the fail

 

[chesterfield hooligan]

Hi it sound's like you have air in the system and require's bleeding

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[blamehofman]

means? lol!

Yeah going back to my old one

 

[Boo]

Er, first, I think you mean the other way round. 220C and various bits under the bonnet will have melted. 220F is about 104C which agreed is too hot for an engine coolant temperature. Coolant additive won't make too much difference but something is wrong beyond just that. Please let us know what vehicle and engine you have (guessing RV given that then temp gauge is in F.)

It is a Winnebago Brave with a 7.4 Vortec Chevy engine

 

[scotjimland]

If you removed the cap whilst still hot it will boil over because of the pressure drop.

At shutdown, the temperature will go up and the engine will boil over. Engines can have an operating temperature of as high as 265 f / 129c When they are under pressure the coolant will not boil. Release the pressure and they boil over.

You need to check a few things. Replace the radiator cap and see if that helps. It may not be holding the pressure. If so, that was probably the problem. If not, replace the thermostat and flush the system.

Other possible causes of overheating are

* a bad fan or an electric fan that does not continue to run at shutdown.

*Loose belt, that is not turning the pump properly,

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[Dodgey]

Hey Boo:thumb:

Hopefully you know not to take the cap off when hot?

Anyway, where does it come out from and at what point ie full temp, just as it hitsfull part way through the warm up?

Ultimatly yes, you should top up with an antifreeze mix at all times, but not doing so wont cause a motor to overheat.

 

[Boo]

Thanks all for your replies,

Looked today and the water level is up to hot even when its cold, I maybe think I might have put too much water in the expansion tank oh:

I'll test the rad thermostat tonight in a bowl of boiling water...........cheers all and good to be back :thumb:

Boo

 

[wivvy's dad]

Aaaah, I think you've just solved your own problem. The expansion tank should have virtually no fluid in it when cold. It is there to take the hot fluid when it has warmed to operating temperature. When the motor cools, the fluid will return to the radiator. Fluid should only be added to the radiator.

There were a number of problems over the years with Honda Pan European ST1100 motorcycles overheating. This was eventually traced to the pipe between the radiator and expansion tank slowly perishing over time, and developing minute holes. These holes didn't allow fluid out, but did allow air in. Over time, as more air was sucked into the radiator, the fluid level dropped, being replaced by an equivalent amount of air.

Eventually this small amount of water rose higher and higher in temperature, and serious overheating started. Top up the rad or expansion tank, and it would soon boil away.

Replacing the tube between expansion tank and top of rad solved the problem. I did this on all of mine, and on BMW's too.

I know this may very well not be your problem, but it's good to be aware of the not so obvious.

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[pappajohn]

i believe most american ford and chevvy engines require a specific coolant but im sure this is just for the special anti-corrosion/lubrication properties.

it shouldnt boil that easily even running on nowt but water.

think back quite a few years.....cars only had antifreeze in winter and usually had that diluted to nowt during the summer.