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- - D2 inline thermostat mod ? (https://landroverforums.com/forum/discovery-ii-18/d2-inline-thermostat-mod-32216/)

D2 inline thermostat mod ?

i saw this on other boards....does anyone have a write up on it?

like where do you buy the parts...where to cut hoses?

I spoke with Josh a couple of days ago and he thinks he may have his write up sometime this weekend. There is also a write up on the LRO about it.

i saw the other write up...buts i dont think its good enough to jump on.....i like josh's way of explaning things

Did this to mine about a week ago. Its very simple, same as replacing hoses really. I posted the part numbers for what i used in the thread on the other board.

why isnt this the best post of the year....does no one see the value in a reliable cooling system?

i have orderd the parts... now i'm waiting for a write up

I would caution against converting to an inline thermostat (or conventional thermostat) if you live in colder climates. The original set up was designed (as I understand it) to mix water from the radiator and the engine together so that the block didn't receive a sudden rush of extra cold water which could shrink the liners and cause a problem.

Where I live, the radiator may very well contain coolant which is 30 degrees below zero while the engine warms up. With an inline thermostat, when it opens, the coolant moves into the engine without blending and you'll see the temperature gauge drop like a rock. OK for an cast iron small block chevy but might be a problem for an aluminium engine with sleeves.

Note that I'm not immune to hot weather. Summer temps often reach 100 degrees. If you consider the wind chill in January, my Rovers have to operate from 60 and 70 below zero to 90 degrees (F) and above, so the cooling/heating system gets a real work out.

Rave specifically states that the design of the DII cooling system is for passenger comfort.

General
The cooling system used on the V8 engine is a pressure relief by-pass type system which allows coolant to circulate
around the cylinder block and the heater circuit when the thermostat is closed. With coolant not passing through the
radiator, this promotes faster heater warm-up which in turn improves passenger comfort.

By-pass flow valve
The by-pass flow valve is held closed by a light spring. It operates to further aid heater warm-up. When the main valve
is closed and the engine speed is at idle, the coolant pump does not produce sufficient flow and pressure to open the
valve. In this condition the valve prevents coolant circulating through the by-pass circuit and forces the coolant through
the heater matrix only. This provides a higher flow of coolant through the heater matrix to improve passenger comfort
in cold conditions.

So the problem with this is that as the performance of the water pump, radiator, heater matrix, etc diminishes,(due to lack of maintenance) it becomes harder for the coolant to flow efficiently thereby heavily contributing to our genetic head gasket disease.

My temps are 182-193 between hwy driving and idle in stop and go traffic...70k miles with stock radiator, water pump, hoses, etc. I have done two COMPLETE coolant flushes in the last 15k miles of my ownership.

Compare that to 200-210+ temps in other DII's I've worked on down here ranging from 53k miles to 150k miles.

Quote:

Originally Posted by 03discoman (Post 185408)

i saw the other write up...buts i dont think its good enough to jump on.....i like josh's way of explaning things

Thanks! It's my way of giving back to everyone who has helped me.

How to do the inline thermostat mod

Watch your oil temps though. Too low is bad also, could lead to sludge formation, excess fuel dilution and moisture in the oil.