Blown coolant hose, how screwed am I? (Turns out, not at all!) -- Update: I'm most likely screwed :(

That's what I'm thinking at the moment. Without seeing the gasket no way for me to be sure about that though.
 
I’d say the hose blowing was a symptom of overpressure rather than the cause of the gasket failure?
 
sorry to hear it’s a head gasket issue

They are few and far between so that’s really unlucky

Before you dive in and go the whole hog of the mechanical route it’s worth considering steel seal

I know some people see it as terrible, but having had a previous m54 engine have definite coolant gasses in the coolant system I bought a bottle and it 100% worked.

I did invest in a cheap head gasket tester kit which showed before and after that the issue was fixed.
 
Pondrew said:
So....would it seem that your initial hose blowing caused the engine to get hot enough to damage the head gasket??
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I’d suggest the gasket failure over pressurised the cooling system and the pipe was the weakest point and popped
 
Pondrew said:
Is that not what the expansion tank/ cap is for, though??
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Cap is screwed on tight. Would take some pressure to burst the tank before It popped a hose off. I’m not sure it is truly an expansion tank. Those are there to take expanded hot water then syphon it back in as the coolant cools and contracts. What we call an expansion tank is in fact a part of the whole pressurised system. Harking back to my 2.8i Capri, it was in fact termed a degassing tank.
 
enuff_zed said:
Cap is screwed on tight.
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Yes but the caps have a pre-determined 'release pressure' as a fail safe for this very reason.
I know feck all about engines but I know a little bit about cooling/ heating systems and pressure/ temperature.

The expansion tanks are just that, which is why they are only ever filled with liquid to around half way. The rest of the space is to allow for the expansion of the coolant at high temperature, thus keeping pressure down.

To 'blow a hose' suddenly (assuming it was sound before) would require very high relative pressure (probably around 5 bar/ 70psi minimum). Car cooling systems are not pressurised by anything other than coolant temperature in a hermetically-sealed system. If they work at more than 20 psig I would be surprised. Water pumps just circulate, they don't pressurise.

Not having a pop, just find it interesting.
 
Pondrew said:
Yes but the caps have a pre-determined 'release pressure' as a fail safe for this very reason.
I know feck all about engines but I know a little bit about cooling/ heating systems and pressure/ temperature.

The expansion tanks are just that, which is why they are only ever filled with liquid to around half way. The rest of the space is to allow for the expansion of the coolant at high temperature, thus keeping pressure down.

To 'blow a hose' suddenly (assuming it was sound before) would require very high relative pressure (probably around 5 bar/ 70psi minimum). Car cooling systems are not pressurised by anything other than coolant temperature in a hermetically-sealed system. If they work at more than 20 psig I would be surprised. Water pumps just circulate, they don't pressurise.

Not having a pop, just find it interesting.
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I can only speak as I find and I’ve had three other instances on other engines where a head gasket has blown a hose off. Possibly as it produces a localised ‘bubble’ which impacts the hose before it makes it as far as the ‘expansion tank’.

Because you'll ask:
2.0 V4 Capri, 850 Mini and recently an M54 3.0 E85
 
enuff_zed said:
I can only speak as I find and I’ve had three other instances on other engines where a head gasket has blown a hose off.
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How did you know it wasn't the other way around, though?
Once something has 'gone' it is very difficult to ascertain in which order it happened, surely?

A catastrophic head gasket failure to blow a part of the cooling system instantly is surely unlikely? I understood they start to 'weep' first, which give other indications. I would have thought a loss of compression in the cylinder(s) would be first, no?
 
Pondrew said:
How did you know it wasn't the other way around, though?
Once something has 'gone' it is very difficult to ascertain in which order it happened, surely?

A catastrophic head gasket failure to blow a part of the cooling system instantly is surely unlikely? I understood they start to 'weep' first, which give other indications. I would have thought a loss of compression in the cylinder(s) would be first, no?
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We can take this around in circles all day long. I've related my experience.
Others will obviously dispute that. So be it.
 
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