Thread: Heater core by pass

Re raising engine temps - clamping will interrupt coolant circulation and compromise efficient heat exchange inside the engine ...

Originally Posted by onebob

Re raising engine temps - clamping will interrupt coolant circulation and compromise efficient heat exchange inside the engine ...

Actually by clamping off the heater water feed it should Increase the water flow through the engine Not Decrease it

Lemo said it better than me, but it’ll be whatever it’ll be ....

happy days

Interesting to test the Temps before and after the bypass and if just clamped?

Originally Posted by Lemo

Interesting to test the Temps before and after the bypass and if just clamped?

All the old Holden's, Falcons and Valliant's had a cable operated tap on the heater feed pipe and these never overheated just because the heater was turned off.
I have been told and have read that the cooling system on a D2 is designed the Heat up the engine and the interior of the truck rapidly, Being designed primarily for the UK, US and European market I can understand that reasoning But it is not helpful in most of Australia.
The Coolant circulates around the engine until it gets to operating temperature and the thermostat allows flow of cooled liquid from the bottom of the radiator when the engine gets over that operating temperature.
Closing off the flow to the heater matrix will have NO effect on the overall operating temperature on the engine as long as everything is working to specification.
Running the heater when your engine is getting hot Will help to cool it down, I have had to do this on occasions in the past and I can assure you it is no fun in the middle of a 40C+ day.

Personally I have absolutely No problems with the way the heater and air con are set up originally in my D2a, On a Hot day I stay nice and cool and on the rare event of having a cold day I stay nice and snug So I can't see any valid reason to make this modification myself.

Am doing the mod because I am geeting hot air from the heater into the cabin (actually quite a lot). I can either fix the problem with the heater - dont want to think about that, or stop hot water going through it. I really never need a heater in Cairns, but I do need a nice cool cabin.

Anyway I clamped that sucker, the difference is huge. Damn my Disco is cool.

All this was inspired by my blower failing. I have been cooking for a week, the lack of a driver side window motor which failed 2 weeks earlier didnt help.

Research told me that it was getting a bad power supply, due a bad connection (corroded?). I have done a bypass of that power supply, and now it is working again.

Originally Posted by Freightdog

Am doing the mod because I am geeting hot air from the heater into the cabin (actually quite a lot). I can either fix the problem with the heater - dont want to think about that, or stop hot water going through it. I really never need a heater in Cairns, but I do need a nice cool cabin.

Anyway I clamped that sucker, the difference is huge. Damn my Disco is cool.

All this was inspired by my blower failing. I have been cooking for a week, the lack of a driver side window motor which failed 2 weeks earlier didnt help.

Research told me that it was getting a bad power supply, due a bad connection (corroded?). I have done a bypass of that power supply, and now it is working again.

There is quite a bit of "Stuff" under the dash that can go belly up, At least now you don't have to cook yourself and you can unclamp at any time you want the heater back on.
Has this affected the engine temperature at all ?

Doesnt seem to have, though I have only done a couple of short trips this afternoon.

I will keep you posted. If all goes well, I will put in a ball valve. You know, so it is ready for that big trip down south in winter.