head cracked? or head gasket? how do you tell?

[millard]

1999 110 HDi Excutive estate

well I've posted a couple of threads over the last week or so and have gradually fumbled my way towards having my head gasket done by a garage, about 600 so far is the best quote, that's with a skim.
However, the mechanic who quoted me that figure tells me that he's done a few PUGs where the head still leaked after he'd done the gasket, much to their owners' disappointment. Turns out on a few occasions that the heads were cracked or holed, so the gasket wasn't the problem at all.
I got the impression that he was a pretty fair guy and not just hustling for a bigger job/more money.
So is there a way to tell/test the head either before removing it? or once it's off?
If a crack can be detected once the head's removed then at least I can look at a recon head and save dosh and heartache.
any experience/advice most gratefully received.

btw
I had a sniff test done and it failed.

cheers
Millard

[Doggy]

I believe you can try a penetrant dye as decribed here: http://en.wikipedia.org/wiki/Dye_penetrant_inspection
but have no personal experience - maybe someone else can confrim?

[ally406]

I would say if you're taking the head off, and there's any doubt what so ever, get it pressure tested as a matter of course before proceeding with any other work. It will only be another £30 or so.

[lozz]

As mentioned above,

preasure testing,
the company that will skim the head will know if its cracked,
the company iuse wont skim one until theyve checked it, idont know if they all do that tho,

[millard]

I didn't realise they could pressure test the head off the block.
Simple then, I'll ask the mechanic to get them to do that.
Cheers fellas.
millard

[lozz]

Millard,
just being honest here,

600 notes is abit ott for a headgasket replacement,

preasure test and skim incl gasket isnt big money,
even with cambelt tensioner and water pump getting replaced at same time idont see how anyone can charge 600 notes
id get some more quotes mate,

if hes saying some headgaskets have leaked after hes replaced them that wouid make me think hes not having the heads skimmed & preasure tested,its crucial the head is skimmed once the headgasket as failed,

if theres anyproblems with the head upon testing they will tell you straight away if its scrap or not,

[millard]

funnily enough he just got back and said it's 800, he made a mistake !!!
Another quoted 921 and a third quoted 800 as well.
Must admit I didn't think it'd be that much.
Maybe I'll post another thread asking for recommendations for decent mechanics.
cheers

millard

[gumby6371]

A full head gasket kit, stretch bolts, cambelt, water pump and associated gubbins, auxilliary belt and tensioners (belts coming off any way so might as well) pressure test and skim plus labour - I wouldn't grumble at £600.

HOWEVER

If the guy says he's done them and they still leak I'd want to see evidence of what work has actually been done, sounds to me like he's just changing the gasket and hoping for the best. I'd also make sure he was putting the correct thickness gasket in after the head being skimmed.