Land Rover Forums - Land Rover Enthusiast Forum - 2004 Disco - Overheating after head gasket and ALL cooling components replaced

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Quote:

Originally Posted by akbrewer (Post 531666)

Hello all,

I was mistaken regarding the thermostat, it is not an OEM, but the NAPA 180 degree thermostat. The part number is NBH 34723. Since this is a 180 degree thermostat, should I still purchase the Land Rover 180 degree thermostat that was recommended in this thread?

AK, the inline thermostat mod will take you an hour and cost about the same as an OEM thermostat. Really does improve your engine temps and it is all upside for the rest of the life of the truck.

But if you want to stick with the original setup then in hot climates the gurus recommend the 180 soft spring thermostat, which is designed for diesels. This is the one.

you probably want to check it with a digital thermometer to see when it is opening

Napa thermostat is made in China Junk.

Get the land rover 180 degree.

People put in Motorad 180 degree and those are junk too.

Sorry but you need to pony up $80 for the right genuine part.

Your engine is not worth holding out for $80f for the correct thermostat.

Just stay home from going out on the town for a week or two.
That will pay for it.

Or do the inline mod and your thermostats will cost between eight dollars (cheapie--stay away) and 11 dollars (tops!). Sorry. Broken record... but it really is a great mod.

Quote:

Originally Posted by Externet (Post 531403)

Can you explain that, please ?

If a cap does not hold pressure; would that cause overheating ? Or just cause coolant/steam loss and because of that loss, could overheat from lack of coolant ?

Am sure without a cap will not overheat. It will not pass 100C / 212F.
But we have to define a temperature borderline to name it overheat.

I propose defining overheating as over 110C / 230F --->Would that be reasonable ? Is there an already established consensus ?
New cars with idiot pointers tell us nothing, as what is factory 'normal'
If I remember well, the top 'white zone' on Land Rover is 111C

The only way a cap not sealing causes overheating, is allowing the water in the mix to reach boiling point and escaping, therefore coolant level goes down and overheating occurs. If you do run without a cap,(unless you use waterless coolant like EVANS Coolant) once your temp reaches boiling point of water, it will escape and overheat.
Waterless coolants actually recommend drilling very small hole in radiator cap, because boiling point is 375* and you want the water to escape and replace with more coolant until system is totally waterless.

Easiest thing to do is start with ordering the 180 TD5 thermostat. Bleed the system and evaluate the results. It is critical that you find the source of the high temps and correct them ASAP.

What kind of coolant are you using? What color is it?

Thank you all for the feedback. I have ordered the suggested 180 thermostat, and will bleed the system and install the new one. The current coolant is the green from NAPA. What brand do you suggest I replace it with?

Brand of coolant is not as important, just use any conventional green coolant,
Bleeding system completely out of air is the real key,

I think the concern was whether you were using red/orange coolant (dexcool), which can thicken and sludge... especially when you switch coolants from red/orange to green.

more important is that the dexcool is never allowed to mix with air. It then starts solidifying which is were your real problems come from.