6n2 cranks but wont start

[mrg123]

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[zollaf]

amazing how you sussed out it would start if you jack the back end up ???
anyway, you mention its got loads pr pressure in the header tank ? thats a sure sign the head gasket is blown. so, header tank cap off, back on, spin it over on the starter and theres pressure ? or does it need to run to create it, but anyway, even if you just start it then turn it off theres pressure ?

[mrg123]

Yep, there is pressure. If starts for maybe 10-20 seconds, idles perfectly. I'm thinking head gasket as well but usually a car will run with a blown head gasket but run like crap!

[zollaf]

well pressure quickly like that means one thing, head gasket. maybe there is a different fault, but it almost certainly shows signs of a failed head gasket, regardless of what engine it is we are talking about, whuich is something we dont know. well, you do but no one else does

[mrg123]

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