Coolant Change Help.

Had overheating problems on my D2, thought it was the thermostat but having now got at it I found that the bottom hose was poorly fitted nearly fell off in my hand

Anyway that's by and by and no **** taking but I am having difficulty locating the drain plugs on the block I thought I was looking for two fairly big square plugs but I can't see them least wise not without jacking the motor up and getting underneath properly, so in words of one syllable where are they? Do I need to jack the motor up?

Cheers

Bill

If it's the same as the 300TDi, you just have to unclip the bottom rad hose... ****e innit!

The early V8 had the drain plug for each block my 3.5 had, but I can't see them on the 3.9 anyway I don't think I could get to them.
I cant even get to the hose clips on the bottom hose I just remove the small branch hose that goes to the expansion bottle and drain from there.

So just do a flush of the system ie. drain, fill with plain water, run the engine, let it cool and drain again. As I now use the 5 year life antifreeze I don't drain the system very often, I have just changed my coolent so I have no need to bother anymore for another four years.

If you want to just flush the old coolant out remove the bottom hose that will drain most of it, then to flush the block remove the hose that goes from the back of the water pump to the heater and shove a hose in it. Make sure the heater is set to max heat - i.e. open.

If you would rather remove the drain plugs they are located as follows:

One each side of the cylinder block beneath the exhaust manifolds (you'll see them next to one of the core plugs - looks like a wading plug) fiddly to get at when you're lying on your back under the motor.

classic kev said:

If you want to just flush the old coolant out remove the bottom hose that will drain most of it, then to flush the block remove the hose that goes from the back of the water pump to the heater and shove a hose in it. Make sure the heater is set to max heat - i.e. open.

If you would rather remove the drain plugs they are located as follows:

One each side of the cylinder block beneath the exhaust manifolds (you'll see them next to one of the core plugs - looks like a wading plug) fiddly to get at when you're lying on your back under the motor.

Click to expand...

Remove the bottom hose.. not on a 3.9.. Why? as we have air blending heaters

discool said:

Remove the bottom hose.. not on a 3.9.. Why? as we have air blending heaters

Click to expand...

Fair enough! Good call.

Thanks for your replies

Bill

discool said:

Remove the bottom hose.. not on a 3.9.. Why? as we have air blending heaters

Click to expand...

Can you explain that bit , as I did that when I changed my coolant- so I want to know what I have broken now!:doh:

fett said:

Can you explain that bit , as I did that when I changed my coolant- so I want to know what I have broken now!:doh:

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I forget whats in the way now, I will have a look again the next fine day and take a pic, but I know I can't get my hand on the hose either from the top or underneath to pull it from the rad, I don't think I can even get to the hose clip such is the small space, and I don't intend to strip things out to get to it. It's not causing me a problem as I now only drain the coolent every 5 years.

The heater controls blend the incoming cold air flow through the heater and the incoming air flow through the heater matrix via variable dampers so you can get the exact temp from the heater that you require, both sides of the cabin.
There is no tap or valve to control the coolent flow through the matrix so therefore it's always the temp of the engine coolent, although with heater set to cold and the a/c is switched on the flow is restricted.

discool said:

I forget whats in the way now, I will have a look again the next fine day and take a pic, but I know I can't get my hand on the hose either from the top or underneath to pull it from the rad, I don't think I can even get to the hose clip such is the small space, and I don't intend to strip things out to get to it. It's not causing me a problem as I now only drain the coolent every 5 years.

The heater controls blend the incoming cold air flow through the heater and the incoming air flow through the heater matrix via variable dampers so you can get the exact temp from the heater that you require, both sides of the cabin.
There is no tap or valve to control the coolent flow through the matrix so therefore it's always the temp of the engine coolent, although with heater set to cold and the a/c is switched on the flow is restricted.

Click to expand...

So does that apply to 1990 3.9 classic?

I did have a hard time getting that botom hose off with its Y shape (my wrists only just got better)had to bend the fecker hard, glad it didnt break like evrything else does lol.

Wish I had put 5 year stuff in now too!

fett said:

So does that apply to 1990 3.9 classic?

I did have a hard time getting that botom hose off with its Y shape (my wrists only just got better)had to bend the fecker hard, glad it didnt break like evrything else does lol.

Wish I had put 5 year stuff in now too!

Click to expand...

No I don't believe it does as the 200 series disco's have the same heater as 3.5 RRC and I know the heater was not air blending as when changing the antifreeze in thoes days I had to move the dash control to hot, only one heat control then

Yeah thats right, I got just the one!

:doh: Just noticed the Classic bit, I keep thinking disco these days.

This link shows what a 300 series disco dash looks like, but I'm sure u know that. http://www.difflock.com/magazine/Wo...ICK_TIP_Discovery_Dahboard_Illumination.shtml.