Land Rover Discovery (1989 - 1998) - 1996 3.9 Gases in the cooling system.

Honest John Back Room » Technical matters
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Sun 7 Dec 2008 18:13
1996 3.9 Gases in the cooling system. - Raveninghorde
My disco started blowing gases into the cooling system. Took it to my local garage and spent over £800 on skimming the heads and new gaskets. That didn't cure it.

Gases are still getting into the cooling system and after a few miles looses the coolant. The garage says it must be the block. So is it scrap or is there anything else to look for? It's used by the old lady for towing horses so must be reliable.

Edited by Pugugly on 07/12/2008 at 18:17

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Sun 7 Dec 2008 18:40
1996 3.9 Gases in the cooling system. - ex-Triumph man
Sorry to hear the old Disco let you down. Looks as though you did not go to a franchised Land Rover dealer to get the work done on the engine as the skimming of heads is not approved by Land Rover.
Problem may be down to a porous block. At 12 years old, this will be well outwith any factory support.
Suggest another engine or sell the car "sold as seen"
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Sun 7 Dec 2008 21:25
1996 3.9 Gases in the cooling system. - injection doc
Were the heads crack tested whilst removed? If not why not. Does it have an LPg conversion, if so the heads must be crack tested. A cylinder leakage test may reveal the problem. I would guess it may be one of the cylinder bores has become porus. these can be machined & lined to overcome this issue. Normally one of the rear cylinders & often the left bank. With carrying out a cylinder leakage test air may be spotted in the coolant.
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Sun 7 Dec 2008 23:25
1996 3.9 Gases in the cooling system. - Raveninghorde
Heads were pressure tested. No LPG.

Is it worth machining and lining the bores of an engine this old?
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