engine life expectancy of 4.6?

hi everyone i have recently bought a 4.6hse 1997 range rover and am loving it to bits, reading through some stuff on internet ive seen someone say that 70k or there abouts they ALL SUFFER from pourous head issue i suppose he means headgasket issues, mine is now on 81k and currently running like a dream i am worried though there is a major failure waiting round the corner now is this a fact to expect? or treated well can this engine go on to 100 k plus any help much appreciated

i tend to think if it hasnt happend yet it may not!
i had an engine rebuild with replacement block, the engineering firm that did it say they look for an old "seasoned" block thats not cracked, as if it hasnt cracked by now it will probably wont!!!!! fingers crossed lol.

are we talking about block porosity here and cant it be cured by "top hat " liners?

Your probably right there MadHat.
All I can throw in the ring is to say make sure that a 50/50 mix of quality anti freeze and preferably de ionised or distilled water (Hard water is a killer) is in the cooling system. All being well, you should be o.k. don't get paranoid about it but be aware that it can & does happen.

From some fairly interesting research: (i.e a bit of google-foo)
(please don't hate me if this is a repost)
I quote the article on RRKnowledge base:

[FONT=Arial, Helvetica, sans-serif]The porous block myth[/FONT][FONT=Arial, Helvetica, sans-serif]Written by [/FONT][FONT=Arial, Helvetica, sans-serif] - Anthony Grantham[/FONT][FONT=Arial, Helvetica, sans-serif]Moderated on [/FONT][FONT=Arial, Helvetica, sans-serif] - 26th August 2007[/FONT]


[FONT=Arial, Helvetica, sans-serif]The has been much talk about porous blocks on 3.9l and larger V8s - I have yet to see proof of this, or even have someone explain how it is possible - the block has cylinder liners, so for water to enter the combustion chamber via the cylinder, it would have to pass through a liner, not the block.

What actually happens, and I have seen on three engines I have stripped, is that the liner works loose in the block.

One of these was catatrophic the liner moved down, the piston rings came out of the top of the lines and shattered, and the debris spread via the inlet manifold to other cylinders.

On the other two engines, the liners had not perceptibly moved, but the engines were showing the usual symptoms of water loss and air in the coolant.

With the heads removed and the water galleries at each end blanked off both engines were clearlyseen to be dripping water from the joint between number 3 liner and the block at about 1 drop per second under 9psi pressure (applied via a regulated air supply through a fitting in one of the blanking plates)

This is where the water goes/the air gets in, and in some cases the fitting of new head gaskets will mask the problem, but only temporarily - so if you have a Rangie that regularly needs it's gaskets changing due to water loss, this is probably the underlying cause.

My local engine conditioner is familiar with the problem, and has come up with a solution - removal of the original liners, counterboring the block, and fitting top-hat liners - but this costs around £1000. It is a permanent soltion however.

As an aside, I mentioned this to a friend who though now retired worked for many years for the Jaguar Rover Triumph division of BL and its successors, and had involvement in Project Iceberg.

He said that the 3.9 engine came after his time, but stated that in his opinion, and that of many others who were originally involved in Rover's acquisition and development of the V8, there was not enough material in the block to safely increase its bore - time would seem to have proved him right.


Top hats would seem to be the main answer!

Cheers,
Edwin [/FONT]

Nextgen said:

From some fairly interesting research: (i.e a bit of google-foo)
(please don't hate me if this is a repost)
I quote the article on RRKnowledge base:

[FONT=Arial, Helvetica, sans-serif]The porous block myth[/FONT][FONT=Arial, Helvetica, sans-serif]Written by [/FONT][FONT=Arial, Helvetica, sans-serif]- Anthony Grantham[/FONT][FONT=Arial, Helvetica, sans-serif]Moderated on [/FONT][FONT=Arial, Helvetica, sans-serif]- 26th August 2007[/FONT]

[FONT=Arial, Helvetica, sans-serif]One of these was catatrophic the liner moved down, the piston rings came out of the top of the lines and shattered, and the debris spread via the inlet manifold to other cylinders.[/FONT]

[FONT=Arial, Helvetica, sans-serif]Edwin [/FONT]

Click to expand...

this must have been mine, it didnt half make a mess, the conrod snaped and punched holes in the cylinder wall and broke cakshaft in half.....
17 miles from rebuild, i got top hats now!