Right, I have today stripped the heads off my Disco 1 3.9V8.

There are some marks on the head gasket, though nothing really too drastic. However the inlet ports on cylinders 2 and 7 show signs of water contamination, whilst the others all appear clean. Given that both these cylinders are at the end of each bank I reckon on just head gasket issues, though it does have the composite gaskets fitted.

I've run my finger across the top surface of the block and all the cylinders seem flush, so no obvious liner slipping.

Could there really be cracks in boths heads? Does anyone know of a decent garage around North Hampshire/Basingstoke area that could pressure test the heads and also skim them?

I will post pics up tomorrow but it's too dark to take any decent ones now.

Oh and it has never overheated in the 6000 miles I have done, despite needing water top ups occassionally. The closest was on Tuesday when I noticed a problem and stopped the engine as I saw the temperature guage rise.

Jon

You can test your heads yourself, I'm sure someone will be along to shoot me down but I did it.

I bought a cheap bike inner tube from asda, cut the valve bit off along with enough rubber to seal over a water port on the head. I used a bit more of the rubber from the rest of the tube for the other port. Then cut some 6mm steel to cover the holes and drilled holes in for bolts.

I turned the head over, filled with coolant and bolted the steel/rubber covers, complete with tyre valve, over the coolant ports.

I could then pump up the coolant gallery in the head, I did each one up to 30-40 psi (well over operating psi) and left them over night to see if they would leak, which they didn't.

I didn't, but I assume you could, heat them as well so see if they only leak when hot. Sounds like alot of work I know but I just couldn't afford to pay for testing at the time.

Most common failure points seem to be the valley gasket and the ends of the heads where the water passages are.

Gasket quality is a bit variable too.

Peter

listerdiesel said:

Most common failure points seem toi be the valley gasket and the ends of the heads where the water passages are.

Gasket quality is a bit variable too.

Peter

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Definitely agree with all that. Don't scrimp on the head gaskets! Or indeed any gaskets. From my bitter experience I recommend tracking down some Elring ones for the heads.

Ok, I have had a proper look again this morning in the light and what I though were inlet ports are actually the waterway ports :doh: In my defence I had driven to Aberdeen and back(1150 mile round trip) as well as working for 13 or 14 hours, all within the space of 48 hours

Anyway I have taken a couple of pics of the heads, and I reckon on close inspection that there is some water leaking across the head.

I just need to find someone close by to skim them for me then I can start putting everything back together and crossing everything I have, that I have cured the problem.

Thanks for the suggestions blackvoguebeauty, I presume you got yours skimmed, or did you just reassemble?

Reintz is another good brand.

When we bought off-the shelf gasket sets, we found that many didn't have 'top' marked on them and many had valve stem caps that didn't fit at all, not just a little bit, they were nowhere near.

Reintz is good, I haven't used Elring, but as a brand they are well enough known not to sell rubbish.

Peter

I've ordered the gaskets etc, and my local factors deal with Reinz so I'm glad you've said that

Found someone to skim the heads too, down in Winchester so dropping them off in the morning.

Fingers crossed this solves the problem when I rebuild. Need a few LPG associated bits as well as whoever installed it fitted the hoses so that they would get kinked.

Despite the problems, I'm still glad I bought the car, especially as the main reason was ease of maintenance to be able to fix most problems myself.

jonnier said:

Thanks for the suggestions blackvoguebeauty, I presume you got yours skimmed, or did you just reassemble?

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I did yes, they were 2nd hand off ebay so I wanted to pressure test them first before getting them skimmed.