Overheating at startup.
 

Hi all,
I've been reading about over heating issues here and before I bought a new thermostat, wanted to run a few things by you all for advice:

2002 Disco II with 147,000 miles. When I first start the truck and begin to drive, the temp gauge climbs to hot, then drops to normal after a few minutes of driving. I checked the reservoir and it looks the correct level.

My first instinct is to replace the thermostat. I found a replacement thermo and housing for $25, or genuine part is $45. Question 1: Rock Auto has just the thermo for $5. Can I buy just the thermostat and re-use the existing housing? Should I buy the complete assembly for $45?

Question 2: A while back a small rubber hose that runs to the reservoir became brittle, so I replaced it with a metal hose. Would this be enough to have let air into the system and perhaps it just needs to be bled?

Last question: If I replace the thermostat, I plan to only raise the expansion tank and then swap the thermo without removing the fan. Will I pour coolant everywhere and lose a lot? Will I have to bleed the system after replacing the thermostat?

Thanks!
Jamie

If replacing the thermostat consider the motorad 180 tstat for a 10 degree drop in coolant temps. Motorad 439 180 180F 82C Thermostat | eBay

You could just buy the thermostat but most people don't seem to do that.

You don't need to remove any fans to replace the thermostat, just the fan shroud. Yes you will need to bleed the system. Fairly simple, once you replace the t-stat, with the engine cold unsnap the expansion tank and hold it 8 inches above the upper radiator hose. Loosen the bleed screw. Let gravity burp the system while refilling(still elevating the expansion tank). You'll know when all the air is out when you see a steady stream of coolant coming from the bleed screw. Retighten bleed screw, and top off.

Not sure what you are looking at but there is no such thing as a t/stat housing for a D2.
Do you know how to bleed the sytem and have you?

Thanks for the directions! Sounds easy enough.

Regarding the thermostat and housing, this is the thermostat housing, http://www.roverparts.com/Parts/PEM100990.cfm (the plastic part) and the actual thermostat is inside, which is this: http://www.rockauto.com/getimage/get...ll/QTH102F.jpg which sells for $5.

My question was, can I just open the plastic housing, replace the $5 metal thermostat, or is the plastic sealed and I have to buy the whole assembly?

Thanks!

The plastic is sealed, the first picture is of a complete assembly (the thermostat is inside the housing) the second picture is what you would use in a DI (or any other old school engine)

That $5 t/stat does not go in that sealed t/stat housing for a D2.
As for installing the t/stat do like the rest of us who have been dealing with Rovers for years and bleed it properly so you don't toast your engine.

That sounds fine by me. I will get the $45 original t-stat.

As for "proper bleeding" - is that the description above?

"You don't need to remove any fans to replace the thermostat, just the fan shroud. Yes you will need to bleed the system. Fairly simple, once you replace the t-stat, with the engine cold unsnap the expansion tank and hold it 8 inches above the upper radiator hose. Loosen the bleed screw. Let gravity burp the system while refilling(still elevating the expansion tank). You'll know when all the air is out when you see a steady stream of coolant coming from the bleed screw. Retighten bleed screw, and top off."

I downloaded the RAVE manual, I saw the section to replace the thermostat, but no bleed section.

Thanks!
jamie

Sounds like your describing a D I t-stat

Here is a pix of a D2 stat, if it would open easily it would not have been chewed open by the 40 hp turbo squirrel owned by a member.