Overflowing expansion tank..

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Discodiscodisco

New Member
Posts
9
Location
Essex
Hi guys,

My disco is overflowing with coolant. I just replaced the Rad only to find it is still overflowing.
I removed the thermostat to check its operation and tried it without - still no change!
When I removed the expansion cap, the coolant level rose quickly with the engine running, when I tightened the cap and removed the rad bleed screw, it bubbled and coolant ran out but the bubbling wouldn't stop.
I finally removed the thermostat bleed screw and there was no visable coolant, so I removed the expansion cap and watched the level drop until the stat housing filled with bubbling coolant. As soon as I replaced the bleed screw, the expansion tank level rose again.

I'm thinking its probably head gasket failure but confirmation would be ace!
 
Hi,

Sorry I should have explained myself better, the engine is a 300tdi.

I didn't read the forum rules before posting, I will now introduce myself.
 
I have no idea, I'm not at all familiar with these engines. I'm more used to Italian cars and their engines.
I did speak to a specialist who informed me 200tdi's spit a bit of gasket out the back of the head when they go, the 300's however he said just chuff up gasses through the oil filler - which it is not.
 
I have no idea, I'm not at all familiar with these engines. I'm more used to Italian cars and their engines.
I did speak to a specialist who informed me 200tdi's spit a bit of gasket out the back of the head when they go, the 300's however he said just chuff up gasses through the oil filler - which it is not.

??specialist?? Seems to be a bit of a knobjockey, how long you had the 300?
 
two things to check first, is the coolant system getting hot all round, are the bottom/top hoses both getting hot? If not then its your waterpump, if it is then move onto test two... get yourself to a decent garage and ask them to do a chemical head test, this will check for hydrocarbons in the coolant and will tell you if you have a leak between cylinders and the waterjacket. If this is the case it could be a head gasket or possibly a cracked head/block.

Other than that its hard to diagnose via a forum, get a garage to have a check over it and see what they say...
 
On closer inspection there is a grey oily residue around the P gasket suggesting that it has failed. I have also found the thermostat has failed, unsure about the waterpump...
 
I have replaced the radiator, P-gasket, Waterpump gasket, Thermostat and bled the system as per forum instructions so that there is no air at all in the system.

When I start the engine, water is ejected from the expansion tank whether or not the cap is on. An air lock keeps developing in the thermostat housing.

Do you think its head-gasket time?
 
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