Thread: 3.9V8 oil cooler lines

Plumb in a Aftermarket cooler from someone like Earls.

And yes, the engine should have one

Thanks for tihs Tombie!

I'd never heard of Earl's and they are just down the road my my old place. I like their coolers!

You should either plumb the lines to the radiator or have a thermostat in the circuit. Oil Thermostats are available from speed shops.
If you do not do this the oil never gets to temp and the water will not boil out. I had a 77 with a cooler and no thermo when I bought it. I found all of the vapour vent lines completely blocked with hard crud. I had to drill out the hoses and inlets to the carbys.

The thermostat has a slight downside. I was in the Brindabellas one day camping at the bottom of a big climb out. near the top of the climb I lost oil pressure for about a second. Looking back I think that is when the thermo opened and the cooler had no oil in it.

I wonder with modern oils whether you need an engine oil thermo. I think the makers put them there for a worst case scenario, say towing at 45degress with old cheap oil. I think if you use semi -synthetic and change it regularly there is no problem. I once drove 1900Kms from Amman to Riyadh in summer at 50-55 degrees with oil temp pegged ( maybe 230) . The car used a lot but there was no engine damage. That was in 1985 when the best oil available was Shell Super 20-50 dino.
Regards Philip A

The oil cooler on the 3.9 is just through an adaptor that Landrover fitted between the motor and the oil filiter. If you wanted to disconnect the oil cooler function, you would simply remove the adaptor and not have to worry about rerouting hoses.

But as suggested already, I would add a aftermarket cooler or one from a series vehicle.

Thats a really interesting point re air purging. I'll get another cooler for it then, the site that Mike posted has some really good coolers by the looks of it. I saw those themos that you were talking about phillip also and they'll probably be a good idea as the original setup goes through the radiator which I assume will produce a minimum cooling temp for the oil and so gets rid of the need for the thermo on the factory setup. r.over, thank you also. I'll pull the bypass bit out then until I can get everything together to refit a cooler - that makes life easier for moving it around etc.

Simon,
I just bought a P38 oil cooler which I have mounted up high in ront of the radiator. I still have to find a sandwich adaptor so I can hook them into the engine.

If you dont want to use a cooler then I will happily take the adaptor you have off your hands.

Also, on the topic of oil coolers (sorry to steal you thread) on the P38 auto oil cooler, there is a couple of wires from a sensor on the side.
Was this just a temp sensor?
I am going to be using the auto cooler as an engine cooler and I just hoped it wasn't some king of thermostat shut off or the like.

Originally Posted by walker

Simon,
I just bought a P38 oil cooler which I have mounted up high in ront of the radiator. I still have to find a sandwich adaptor so I can hook them into the engine.

If you dont want to use a cooler then I will happily take the adaptor you have off your hands.

Also, on the topic of oil coolers (sorry to steal you thread) on the P38 auto oil cooler, there is a couple of wires from a sensor on the side.
Was this just a temp sensor?
I am going to be using the auto cooler as an engine cooler and I just hoped it wasn't some king of thermostat shut off or the like.

Is that a P38 engine oil cooler or an ATF cooler that you've used for the engine oil? I was wondering if the current fitting will just go straight on as they looked to be high pressure fittings (not sure if it is actually high pressure though). I'll refit it all up again though.

If the P38 ATF cooler is the same as the Disco2 one (I think its just a larger version of the same???) there should be an ATF temp sensor at one end in the tank.

Originally Posted by r.over

The oil cooler on the 3.9 is just through an adaptor that Landrover fitted between the motor and the oil filiter. If you wanted to disconnect the oil cooler function, you would simply remove the adaptor and not have to worry about rerouting hoses.

But as suggested already, I would add a aftermarket cooler or one from a series vehicle.

^^^that, it just undoes and screw the filter back on

Don;t worry about high pressure fitting, hoses and clamps, if done properly will be ample