Disco Overheating

[bordonladdie]

Since renewing the water pump on my 1997 Disco 1 ,with 130,000 kms I am experiencing constant overheating. I've bled and rebled the cooling system,removed the thermotstat . After a short ***,2/3 miles the temperature gauge goes up in the red.At times if I continue to drive, the temperature drops back to normal, other times it just remains on the red. Could it be a blown head gasket? There is no loss of power or white smoke from the exhaust, but there is loss of coolant.Also the coolant can be heard boiling in the expansion tank after switching off.
Your help is appreciated. thanks

 

[joey]

I would stop driving until you had it checked out. If you drive it and it is overheating plan to buy a new engine real soon. On the other hand it could just be a bad sensor. Either way have it checked unless you like spending money.

 

[Disco Mike]

As Joey has said, stop driving it.
Reinstall a new t/stat, running without one can cause the engine to run hotter. Have yo check your 2 electric fans as well as the mechanical one, are they all working when the engine is getting warm?

 

[bordonladdie]

Thanks ,Mike and Joey. I had a small leak in the system which I could not pin point , so I took the opportunity to put some radiator stop leak in the system right after I had refitted the water pump. Eventually, I took the cylinder head off and discovered that this Stop Leak stuff had bunged up the water jacket holes in the cylinder head. Engine runs fine now.

 

[joey]

Stop leak should only be used in an emergency in my opinion. Carry some if you on the trail and you spring a radiator leak... otherwise I never use it.

 

[Disco Mike]

To add to Joey's last post, if stop leak has to be used, only you one that has no inert material, like shaved copper, or aluminum, it will just come back and bite you.