Thread: Who is running a PEL500110 thermostat in their D2

Were the new thermostats Genuine LR parts?

I'm interested as I'm probably going to change mine out soon (td5) as preventative maintenance.

On my 90 Rangie I bought a few new sensors that were aftermarket, fuel temp, coolant temp, etc and every one was useless - ended up replacing with the original sensors and they're still there five years on with no problems.

PEM100990 - Cream is 88° With hard Spring (Designed for Diesel and V8 applications)

PEM101020 - Black or Cream is 82° With Hard Spring (Designed for a V8 and used as a stopgap with K4 engines)

PEL500110 - Grey is 82° With Light Spring (K4 engines)

You need the PEL500110 The hard spring prevents flow through the radiator at low speeds and so in our ambient temps runs hotter. I have it in mine (V8) and sits on 87.7 at idle in full sun on 35+degree days. On the freeway drops to 84.

You can't really install them the wrong way as there's 2 outlets on top and on underneath.

I changed mine pre radiator change and it only dropped a little, after the new rad, coolant (Penrite purple) and water wetter dropped to very stable temps that I'm happy with. There's no effect on cold starts and increased fuel consumption with cooler running as the cold start system shuts down at 55 degrees.

The 100990 is the std Aust spec thermostat. 101020 is gulf spec and the 500110 is actually from the freelander.

Originally Posted by bidds

Were the new thermostats Genuine LR parts?

I'm interested as I'm probably going to change mine out soon (td5) as preventative maintenance.

On my 90 Rangie I bought a few new sensors that were aftermarket, fuel temp, coolant temp, etc and every one was useless - ended up replacing with the original sensors and they're still there five years on with no problems.

Yes I changed with Genuine LR thermostat.

The hard spring prevents flow through the radiator at low speeds and so in our ambient temps runs hotter.

I think the opposite
the softer by-pass spring causes more coolant to by-pass from the radiator,back to the top Rad hose instead of forcing through the thermostat & into the block.
equals less flow to block & hotter running on the HWY.
check out the flow chart on RAVE
The by-pass valve flows back to the top rad hose & in the top of the rad,

now im confused. given that the engine spends more of its time at low speeds and high revs are usually for a short time only, would i want a hard or light spring?

Then why is the softer spring the unit for hotter climates? Everything I've read (and it's a substantial amount) details the spring as allowing flow to circulate to the heater area at idle and allow the system to warm up quicker.

From RAVE:

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 produces a higher flow of coolant through the heater matrix to improve passenger comfort in cold conditions.

When the engine speed increases above idle the coolant pump produces a greater flow and pressure than the heater circuit can take. The pressure acts on the flow valve and overcomes the valve spring pressure, opening the valve and limiting the pressure in the heater circuit. The valve modulates to provide maximum coolant flow through the heater matrix yet allowing excess coolant to flow into the by-pass circuit to provide the engines cooling needs at higher engine rev/min.

The spring is a pressure relief if you like, so if you go changing spring rate it will change the by-pass rate,RAVE shows by-pass flows back to the top rad hose, not through the engine.
I can only tell you mine ran hotter, and according to the post, thats what started thread.
I also had a radiator less 6 months old, I wasted about $70 bux on that thermostat, its sitting back in its box.

Hello,
Just got my engine back together and put in a PEL500110 runs really hot will put the normal one back tomorrow as engine is hot. Took a while to bleed I installed a new water pump as well the temp does drop at tick over but anything over 1500 rpm she just gets hotter.
Ian