Coolant change '92 Defender

Hi guys, need to get this done but have a couple of questions:

1) what coolant to use ?
2) assume it's as simple as dropping the bottom hose off, draining, refilling and running up to temperature ?

Thanks in advance

There'll probably be range of opinions about coolants.
I think the 300Tdi can air lock when you fill it. Not sure about the 200Tdi, so wait for an answer from someone who knows before you do anything! I'll be interested in the answer myself, but for the 300Tdi

You will need the 2 year life plain ethylene / glycol coolant (generally blue in colour), don't use the modern 5 year OAT stuff (generally red) as it uses different corrosion inhibitors which may be unsuitable for some of the metals in the engine.

Mr S1 said:

Hi guys, need to get this done but have a couple of questions:

1) what coolant to use ?
2) assume it's as simple as dropping the bottom hose off, draining, refilling and running up to temperature ?

Thanks in advance

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Not sure if the 200 has a block drain point like the 300 (just behind the alternator0, if it has use that to get the coolant out the block

Kwakerman said:

Not sure if the 200 has a block drain point like the 300 (just behind the alternator0, if it has use that to get the coolant out the block

Click to expand...

they all do going back to first 2.25

Tremendous.
What about filling procedure, gents?

Kwakerman said:

You will need the 2 year life plain ethylene / glycol coolant (generally blue in colour), don't use the modern 5 year OAT stuff (generally red) as it uses different corrosion inhibitors which may be unsuitable for some of the metals in the engine.

Click to expand...

oat is fine,theres no different metals just cast iron, steel and ali

Al2O3 said:

Tremendous.
What about filling procedure, gents?

Click to expand...

just fill till it overflows its a simple system, if expansion tank is over full it will find the correct level

Cheers, James. Does that go for 300Tdi too?

yes the same

Cheers.

jamesmartin said:

they all do going back to first 2.25

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Also on the very first diesel the 2.0 litre.

I run both our 200s on the blue gear,
Not sure I would put oats in them, worth some research loads of info on the classic forums where people have had problems putting modern coolants into old power plants.

200 filling, remove header tank cap and rad top bung, fill system up via rad bung until header tank level is correct fit the tank cap, then keep filling via rad until its fill, refit bung and drive it, recheck afterwards.
300 do the same but use the plastic bung on top of the stat housing.
Both systems are ****e as the header tank level is lower than the coolant level in the cylinder head!

Great, thanks chaps !

jamesmartin said:

oat is fine,theres no different metals just cast iron, steel and ali

Click to expand...

You can also have copper (and solder) in the rad and heater, brass for thermostat and temp sender. I think it is the copper/solder which causes an issue as modern engines don't generally have them in it.

Stick to the blue stuff to be sure. The previous owner of my 200tdi engined 110 had used red and I had the rad blow throw to the oil cooler. May just have been a coincidence, but I've read about similar incidents when red has been used instead of blue.

Point to note. The plastic bung on the thermostat housing will break. Not "might" or "maybe", it WILL break. Ask me how I know.

Get new metal rad and stat housing bungs

SteNova said:

Get new metal rad and stat housing bungs

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Get self-bleed radiator ones from the plumbers merchants ...

SteNova said:

Get new metal rad and stat housing bungs

Click to expand...

The 200 should already have the metal one, its the 300 that had the plastic ones as std.

If you want to avoid making a huge mess when draining the system, I was once given a very simple tip and it works wonders. All you need is a length of rubber hose, maybe 8mm in inner diameter. Use this hose to siphon the coolant out of the reservoir. Then undo the hose clip at the bottom of the reservoir, remove the hose from the reservoir and lift it as high as you can to minimse coolant loss. Then insert the rubber hose into your coolant hose, push it in as far as you can and syphon the coolant out of the radiator using this method. You should collect 4-5 litres in the manner. Remove the rubber hose from the coolant hose, position a bucket under the vehicle and direct the coolant hose into the bucket. That way you'll empty the reservoir. You'll then need to empty the coolant from the block. I have not yet found a way to minimse the mess to a total minumum.