[TrailsEnd]

I replaced the thermostat in my 99 Disco II, and after replacing it one of the coolant hoses (coming from the bottom of the block back up to the thermostat) is expanding like a balloon. The longer the engine runs, the bigger it gets. Opening the top vent screw releases the air/gas, but it just gets more in there after I close it up again.

Looking for ideas on what could be the problem. It did not have this issue before I changed the thermostat, but it was overheating with the old thermostat (I changed it to try and fix that issue thinking it was stuck).



Any help is appreciated.

Thanks,

Derek

 

[number9]

Your system coolant level may be low. That hose goes to pump, if not enough fluid in block hot gases expand. Did you refill and bleed system after thermostat change?

Possibly bad from stock thermostat, reinstall old one to see.

......

 

[TrailsEnd]

I refilled it but after doing some reading today I may no thave have filled it enough or bled it properly. I will give it another shot tomorrow.

Thanks,

Derek

 

[number9]

Found easiest and least messy/wasteful way to top off/bleed is by removing bleed screw and slowly adding fluid to bleed fitting using a small funnel. I will do this cold, prior to first start of the day with reservoir and cap in place. If reservoir is a bit low top-off to full mark. After a thermostat or coolant change it's a good idea to repeat this process several time/days because it may take awhile to get the most air out of cooling system.

......

 

[redtruck12]

Wow
If the hose has expanded that much it needs to be replaced for sure!
Regardless of the bleeding, that is a lot of pressure. To much pressure!
Why originally were you changing the thermostat?
I assume you put in a 180deg thermostat?
Having that much pressure could be a bad cooling system cap. Or possibly an indication of an internal issue such as a head gasket leak (I am dealing with similar on my 2002 D2)
As for bleeding, you need to bleed it from cold.
Pop the resivor out of its mounting clip and raise it as high as you can hold it without pulling on the hoses, fill with the bleeder cap loosened until you get a steady stream of coolant and no more air. Once you are comfortable you have all the air out close the bleeder and then re mount the Resivor.
Start and run the engine at idle with the resivor cap off, heater on full hot heat you should see a solid stream from the small hole inside the top of the resivior.
Monitor actual temperature DO NOT rely on the dash gauge. They register the same 150 to dam near 240 which is way too hot.
Temp should be under 190deg with a 180 deg stat and under 205deg with a stock stat.
Let us know what you see tomorrow.

 

[Chubbs878]

it has been 1 week since you posted this so I'm sure that you have fixed the problem by now. Is the system working properly now? and what all did you do to make the fix? Thanks for following up.

 

[redtruck12]

:devilEveryone please remember that Internet advice is not always accurate! Always consider the source and make your own judgment
Here is a perfect example of bad advice:devil!

Your system coolant level may be low. That hose goes to pump, if not enough fluid in block hot gases expand. Did you refill and bleed system after thermostat change?

Possibly bad from stock thermostat, reinstall old one to see.

......

Found easiest and least messy/wasteful way to top off/bleed is by removing bleed screw and slowly adding fluid to bleed fitting using a small funnel. I will do this cold, prior to first start of the day with reservoir and cap in place. If reservoir is a bit low top-off to full mark. After a thermostat or coolant change it's a good idea to repeat this process several time/days because it may take awhile to get the most air out of cooling system.

......

:wink

 

[p76rangie]

:devilEveryone please remember that Internet advice is not always accurate! Always consider the source and make your own judgment
Here is a perfect example of bad advice:devil!
:wink

Here is another:grin:angel

Pop the resivor out of its mounting clip and raise it as high as you can hold it without pulling on the hoses, fill with the bleeder cap loosened until you get a steady stream of coolant and no more air. Once you are comfortable you have all the air out close the bleeder and then re mount the Resivor.
Start and run the engine at idle with the resivor cap off, heater on full hot heat you should see a solid stream from the small hole inside the top of the resivior.

Temp should be under 190deg with a 180 deg stat and under 205deg with a stock stat.

There is really no need to do anything with the "resivor". Just poor in about a gallon of coolant with the bleeder cap undone. Start engine and keep on adding coolant until it it starts to overflow from the bleeder. No need to have the heater on as all Land Rover heaters are constant flow, That is, there is always coolant running through it no matter what the temp is set at. Refit the pressure cap and run the engine up to running temp and then switch it off. Carefully undo the pressure cap and you should here a bubbling sound as the system "burps" itself. You might have to do this last step a couple of times to get all the air out of the system

The later D2's came stock with a 180 thermostat. The early ones 190 and there was an interim between the two at 186. So a 180 is "stock". The temp of the thermostat is indicated by the colour of the casing. They can be grey, black or a yellowed white. It is this last one that is the 180 and should be used in all models if you have one of the earlier ones fitted.

 

[WadiRover]

Search the forum for rave recommended bleed process. It's pretty straightforward and one cycle does the trick. I think you can check to see if your thermo opens by chucking it in a pan of boiling water. Maybe just check that the hose connections are the right way round. And I'd definitely change the hose or at least carry it Spare until you solve the problem. Good luck

 

[number9]

Always consider the source and make your own judgment

Source considered.

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