porous/gasket

[conad]

If you cant get your hands on a Coscast, source a normal head, get it pressure tested and it should last AT LEAST 50k miles+++

i want to eliminate the word 'should' and replace it with 'will' so im affraid coscast is the way forward

[Adam]

Just get a gm head and have a sleeve fitted to stop it cracking again.

Or have it done to your current head

[John]

Thought this car had already had the head done?
Yeah i'd go for a repair too.

[meritlover]

how (if possible) would i be able to tell the difference between a pooped head gasket and a porous head?

you take the head off.

there is no other method in finding out with the head on. either head gasket failure or porus head could give you water/oil emulsion depending on whether the gasket has failed between an oil way and water jacket, between oil jacket and bore, or bore and waterjacket. (or any combination)

i dont think you have considered a blown core-plug. this would allow the head to allow water to mix with oil in the rocker cover and the water jacket in the head. the emulsion you have in your tank is very severe. you should look at all possiblities before rushing out to buy a head!!

[Stuart]

cav16 (google), on mig there is also a thread by joff_nova about fixing the "porous" issue.


by the way its NOT sodding porous, its a crack. 100% different issues.

[Count Vaux Alot]

I can get the head repair profesionally done sleeved etc for around £100 considerably cheaper than the £300 odd you would pay for a coscast and there is much less faf as you don't have to swap everything....PM me if anyone is interested i had mine done as a precaution and its a top job!

[Stuart]

£100..... for £5 of bar and 10 mins with a drill........ foooooking ell thats a rip off.

[Count Vaux Alot]

/\ you get a pressure test and the drilling is done on a cnc machine plus a garantee and it wont be a fu=king bodge job by some chump

[Stuart]

ahhh the good ole sales tactic of "it wont be a bodge" to try and justify it.

Is the guarantee only valid if they refit the head? If I were an engineering firm I wouldnt guarantee a repair like that unless I had refitted the head too.... too many variables in rebuilding the engine to just blame the repair job


joffs thread on mig
http://www.migweb.co.uk/forums/engin...ification.html

[Lee]

you take the head off.

there is no other method in finding out with the head on. either head gasket failure or porus head could give you water/oil emulsion depending on whether the gasket has failed between an oil way and water jacket, between oil jacket and bore, or bore and waterjacket. (or any combination)

i dont think you have considered a blown core-plug. this would allow the head to allow water to mix with oil in the rocker cover and the water jacket in the head. the emulsion you have in your tank is very severe. you should look at all possiblities before rushing out to buy a head!!

The nature of where the GM head fails means it will always blow oil into the water system. If you have oil in the water you can pretty much guarantee its a cracked (porus) head. Ive never seen a blown headgasket do the same thing if it goes across and oil/water gallery, invariably it'll gloop up the oil, or do both, but not just gloop the water.

The scenario you mention about the core plug doesnt add up as theres no water in the oil as far as we know