Any mechanics around?

Paradigm

Babbawah wrote: »

It's not possible for a car to pass an MOT with a water leak unless it wasn't spotted by the tester.

Did your mum advise them of the water leak before or after the test?

Is the coolant system a testable item? I think not....

Babbawah

Paradigm wrote: »

Is the coolant system a testable item? I think not....

Leaks are !

Wherever they may come from . . . leaks are definately a testable item.

Marktheshark

arcon5 wrote: »

the cooling system alone would not make the engine cut out and not stop -

Yes it will if it has been leaking and allowing Air in, the air pressurises, allows the water to boil in to steam and creates pressure, lots of pressure .
Just like a steam engine does and bang, the cylinder head lifts off its gasket and the whole thing stops.

It is going to have to be towed away, timing checked although thats them claiming that that put the glurb in the expansion bottle the Glow plugs out and compression tested before anything else.
If it compresses and its timed, crank, check for fuel pressure low and high pumps, then bleed through the system, wire to tech 2 select start all system and crank it.
It should start.

Paradigm

Babbawah wrote: »

Leaks are !

Wherever they may come from . . . leaks are definately a testable item.

I think you'll find that coolant system leaks aren't tested, may advise but won't fail.

Strider590

Marktheshark wrote: »

Yes it will if it has been leaking and allowing Air in, the air pressurises, allows the water to boil in to steam and creates pressure, lots of pressure .
Just like a steam engine does and bang, the cylinder head lifts off its gasket and the whole thing stops.

Air doesn't cause coolant to boil, loss of pressure in the cooling system causes the coolant to boil, the boiling in turn creates air pockets within the engine, which causes uneven heating/coolint, which causes the head to warp, which blows the HG.

pendragon_arther

It takes a lot more than an hour's tick-over to cause a head gasket to blow and the head to warp. I was in a Jeep driving in Kenya (hot) and a similar thing happened but it took a couple of hours driving at speed.

Marktheshark

Strider590 wrote: »

Air doesn't cause coolant to boil, loss of pressure in the cooling system causes the coolant to boil, the boiling in turn creates air pockets within the engine, which causes uneven heating/coolint, which causes the head to warp, which blows the HG.

Air is compressible, fluids are not, that is how hydraulics work.
When water Leaks from a cooling system Air enters that space
The space filled by the air allows steam to build in the Air space and steam creates pressure, that is how steam engines work.
Eventually the expansion bottle level drops and air entering the engine system increases, we now have air inside the engine water chambers and the water begins to boil and steam pressurises the system and the weak point is the head gasket, bang, out it blows often lifting the head as well and thats the compression gone.

What we know removing the waffle the "mechanics" have spouted is they left a leaking cooling system on tickover hoping some snake oil would fix the hole in the raditor, the car cut out, wont re-start and they are trying to blame the timing chain.

Cars blowing heads by overheating is not something new, ask a Rover owner, it is pretty much exactly what you would expect to happen.
As to how long they left it running like this until it cut out, again, we only have what these clowns are saying, it could have been hours.

But running the car with a leak and possibly no water on tickover unattended and now they are puzzled why it wont start leaves me to conclude the OP needs to find another garage.

colino

You are right to be wary of them taking any payment. They are painting themselves out of the picture for potential, future damages, no invoice, no payment, there is no paper-trail they did anything on the car at all.

chrisw

Marktheshark wrote: »

When water Leaks from a cooling system Air enters that space
The space filled by the air allows steam to build in the Air space and steam creates pressure, that is how steam engines work.
Eventually the expansion bottle level drops and air entering the engine system increases, we now have air inside the engine water chambers and the water begins to boil and steam pressurises the system and the weak point is the head gasket, bang, out it blows often lifting the head as well and thats the compression gone.

No, Strider was correct, although rather than air pockets, they are pockets of water vapour. These will form in the system even without air once the water reaches its boiling point and the uneven heating warps the head causing the gasket to fail.

BeenThroughItAll

Marktheshark wrote: »

the weak point is the head gasket, bang, out it blows often lifting the head as well and thats the compression gone.

For the HG to be the weak spot, the coolant hoses, radiator, and the expansion tank cap (with its built in mechanism for releasing pressure) would all have to be unbelievably strong...