Confirmation needed re head gasket

[disco_al]

Right,after 2 days back on the road and only 50 miles I think my hg has gone, just wanted 2nd opinion please.

Hoses are hard, lots of bubbling and very pressurised header tank (takes nearly 5 mins to stop after loosening the cap)

No unusual smoke from the exhaust, apart from earlier when coming down a hill on overrun there was a lot of blueish smoke coming out. Stopped, released the pressure and the smoke stopped. Mis firing when under load, at about 3k rpm, accompanied by a puff of blue smoke at each misfire. Not using oil, no sign of water contamination in oil either.

Other than that runs sweet, smooth tickover and even sounds fine.

So what's the diagnosis guys n gals?

[smallfry]

Which engine is this ?

[disco_al]

300 tdi - sorry

[Jamie_grieve]

If the head gasket is gone you'll normally get bubbles in the expansion tank from cold. I'd say take the cap off and start it, bubbles means gasket gone.

When you say back on the road, from what?

You could try just sticking the thickest gasket on which is the no holes one, one hole is the thinnest, then two, three then finally the no holes is the thickest one. Get a composite gasket, not the metal laminated ones as they can cause all kinds of grief. You won't lose any power with the thicker gasket at all, the swept volume remains the same and the turbo will still boost to whatever it did before.

The head is probably warped between 2 and 3 but you'd be surprised at how much the thick gasket can take up. When you torque it up, after the first 40Nm paint a line on the bolts with tip ex or whatever and then do your 60º turns bearing in mind a flat of a bolt is 60º. You'd be surprised how twisty everything is and having all the paint marks lined up means you're at the same stretch on the bolts. Mind the longer centre bolts get an extra 20º.

Be careful not to over tighten the rocker bolts as they strip really easily then the rocker shaft breaks.

Good luck!!

[disco_al]

Just finished swapping the chassis. It's a relatively new head, swapped it off my old one which had only done 6k miles with it on. From memory it was a layered gasket that went on too. Hopefully it hasn't warped, the gauge never went up into the red, and I topped the water up as soon as the tank stopped bubbling enough to get the cap off

[smallfry]

Just to get this clear..........

You took the head off another engine and fitted it to the present engine.

Were both engines running OK before this ?

Do we take it that it does this straight from cold, or is the engine boiling inside ? Its hard to tell without seeing it.

If it had a gasket from the likes of B***part which was laminated (layered) and probably silver in colour all over ? This is likely the problem............or at least a contributor.

Always use an "Elring" (manufacturers name) composite gasket. Mainly black in colour, and of a softer material.

These should always be used if the head and block are of different materials or both alloy.

The old laminated ones are fine if both block and head are iron

Also cheap stretch bolts are no good either, better off using pre enjoyed Land Rover originals

[disco_al]

Both engines were running perfectly. The one the head came off was retired due to rust. The one it is on now spent 9 months last year being welded, and the head was swapped at xmas, just before the mot. It came off the road again at the end of June for the chassis swap, and was only put back on the road last Thursday. An elring gasket was used at Xmas (won't touch the blue boxes) along with new bolts due to unknown history on the old ones.

Anyway, it was the gasket starting to go on no3. Changed it today in 3 hours (done a few 300's) and all seems fine, apart from a lack of power over 3k and an occasional misfire at the same time, so thinking lift pump and new fuel filter.