Blown head ?

mbunting · Post by **mbunting** » 25 Jun 2004, 20:28

Before I drive the 405TD to the scrap yard, can someone please confirm that this is likely to be the head gasket.
1) Been driving for about 3000 miles since a pipe replacement.
2) Pipe suddenly pops off, and dumps coolant (50% mix) onto the inlet manifold.
3) Stop as soon as I can, make some temp repairs, and fill with water.
4) Soon after, pipe does it again.
5) Take radiator cap off, to be greated by what you would see if you took the lid off a boiling kettle.
I'm getting through an entire system of tap-water in about 20 miles at the moment, although this can be extended if I take the cap off.
I'm planning to remove the thermostat so that air-locks cannot be formed, and the flow of coolant should be better, although the problem will remain.
I can neither afford the time to repair it, nor the money to pay a garrage ( approx 5 - 700 UKP ? ), so the option is to seek another car, and drive this to the scrap yard.
Am I making a mis-diagnosis ?
PS . There is no coolant loss when the engine is off.

bad driver · Post by **bad driver** » 25 Jun 2004, 20:54

Which pipe keeps popping off?
Is it possible the thermo is stuck and the pressure is just building to force the pipe off? If theres nothing else wrong why not run wiothout the thermo for a while, see how it goes. If it runs fine then it will be ok through summer until you can get time / money to investigate and repair properly.
Is it the 1.9?? I have a cylinder head here, needs skimming but otherwise fine, complete with cam, pulley, valves etc. Yours for £30

mbunting · Post by **mbunting** » 26 Jun 2004, 01:10

It's the top pipe of the heater matrix.
When I undo the themo bleed bolt, there is lots of steam, and no water coming out.
The temperature shows this, it stays at cold, then suddenly goes up to 90 !
The engine is the 1.9TD, but at the moment I simply cannot afford the time to do anything myself ( I no longer have a drive, which doesn't help ! ), and the money to pay a garrage for the job would be more than I paid for the car !

PowerLee · Post by **PowerLee** » 26 Jun 2004, 14:05

Hi
If you do decide to get rid of this car, Instead of scrapping it, why not sell it on the forum?

bad driver · Post by **bad driver** » 26 Jun 2004, 18:38

My moneys on the heater matrix being blocked. The pump will fill the head with coolant, then suck it back through from heater matrix to be circulated. If its blocked it will end up creating a vaccumm, causing the thermo to open late as its air against the housing not water hence the sudden jump from 0 to 90 as when it finally opens the coolant hits the sensor already red hot.

mbunting · Post by **mbunting** » 27 Jun 2004, 03:33

If it's any pointer, the car does not appear to be down on power, but pressure deifinitely builds in the radiator, to the extent that putting your hand over it lowers the water level in the radiator, and then taking it off immediately releases a geizer that you would expect to see in iceland !

bad driver · Post by **bad driver** » 28 Jun 2004, 00:56

If its pressurising the rad then It probably is the head or gasket then. Sorry, I just read it as getting too hot. Run it without the thermo. I done it with mine and it really helped with the pressurising and kept the temp under 80.

James.UK · Post by **James.UK** » 28 Jun 2004, 02:47

I dont see any mention of you having bled the system when adding water?? if you dont... then air pockets will form and prevent the water from circulating!!

mbunting · Post by **mbunting** » 28 Jun 2004, 16:12

James,
Unlike the Xantia, bleeding the 405 is difficult, there is a bleed point on the radiator, and the bolt in the thermostat housing, thats it.
I used a header tank, and rocked and revved the car, and closed each point in turn ( lower -> higher )

bad driver · Post by **bad driver** » 29 Jun 2004, 02:18

It should have a bleed point on the matrix as well shouldnt it? Does it not have a degassing pipe as well?

mbunting · Post by **mbunting** » 29 Jun 2004, 03:34

No, there's no bleed point on either of the matrix hoses, nor on the hose connector on the bulkhead ( which is where the Xantia one is ).
It's a real bugger !

bad driver · Post by **bad driver** » 29 Jun 2004, 14:10

Something sounds wrong with it then. Every pug I have seen has one on the matrix pipe connector. I cant see how its possible to get rid of airlocks without it. I think this is the problem. Since that pipe has been replaced its never been bled properly, even with a header tank you will still get an airlock in the matrix due to the layout of pipes.