Porous Block - How to test??

[baz]

Hi All,

I have been advised i have a porous block by my mechanic. I have a 2002 V8 D2 update model. It's only done 90K. I have only recently had the head gasket replaced and had the cooling system flushed. By i still get an intermittent overheating issue due to the build up of gases in the cooling system system.

I don't question my mechanics diagnoses at all as he is an LR expert of 30 years, but the problem is i need to get proof of this to the dealer i bought it off so they can fix the problem. But whenever i go to their mechanic there is never any gases in the cooling system. And they don't want to pull the heads of it to diagnose.

Any help would be greatly appreciated.

[shorty943]

My only suggestion is from the book. Genetic mechanical engineering of course.
This is non-specific, pertains to all mechanical contraptions.
Remove, dismantle, clean, and send to a specialist firm for x-rays. (In exactly the same way an Alloy wheel should be treated after a bump.) The x-ray will show up every tiny little defect in the casting, exactly like the x-ray of your busted arm, leg, whatever.
Basically, take her to the doctor and demand it be properly checked.
Remember to remain seated, and to fan yourself with your rapidly reddening credit card, of course. Sorry. That part is beyond my control.

"And they don't want to pull the heads of it to diagnose."
Reminds me of a friends Harley Ferguson, at normal speeds all good, 2 or 3 mins at 120 it fell in a hole and sounded like it had just busted a piston. The dealer did not want to touch it, as it was still almost new, "can't be anything wrong". I took her bike in and made with the hard man stuff, sure enough, a 1.5 thou bend in an exhaust valve from new. Once the engine was being asked to work it heated and expanded the untrue vavle just enough for it to partially sieze in the valve guide.

Demand it be properly checked.

Shorty.

[PhilipA]

In the UK they pull them down to bare block, then seal all the water holes,then pressurise the block.
There are not too many holes, just the water pump and the transfers to the heads. They use self tappers and washers in them and a plate over the water pump.
After several hours under pressure the water starts oozing out the top of the bad sleeve.
Nearly all bad blocks have a crack behind a sleeve, which then goes to the deck of the block, then into the combustion chamber as the head gasket seals outside the sleeve .
A dead giveaway is a squeaky clean piston, which has been steam cleaned. So a quick and dirty check may be to look in the combustion chamber with a fibre optic viewer.
regards Philip A

[baz]

Thanks, i'm taking it to RACQ to get a written report so i will get them to inspect the piston tops to look for one with a steam clean. Which they will hopefully agree is an issue.

[Frenchie]

In the UK they pull them down to bare block, then seal all the water holes,then pressurise the block.
There are not too many holes, just the water pump and the transfers to the heads. They use self tappers and washers in them and a plate over the water pump.
After several hours under pressure the water starts oozing out the top of the bad sleeve.
Nearly all bad blocks have a crack behind a sleeve, which then goes to the deck of the block, then into the combustion chamber as the head gasket seals outside the sleeve .
A dead giveaway is a squeaky clean piston, which has been steam cleaned. So a quick and dirty check may be to look in the combustion chamber with a fibre optic viewer.
regards Philip A

Surely it would be easier just to replace the motor? :confused:

[Blknight.aus]

a magnetic partical wash will also show it up, but thats still a full strip to find and then once youve got it stripped the cost of the testing costs almost as much as a new block and definately more than a second hand block.

[baz]

what about pressurising the cooling system to get water to come through the sleeve?

But i think i like the sound of inspecting the top of the piston.

[Blknight.aus]

works for cracks but rarely for porisity checks, you'll blow out the welsh plugs, heater pipe unions, or the drain valves first...

[PhilipA]

I think they pressurise to about 60PSI, which would probably blow the radiator to bits.
Regards Philip A

[Blknight.aus]

they take the radiator off and block up the heater pipes with blanking fittings...

[baz]

Thanks for the info. Both sides were replaced when they did the head gasket. RACQ couldn't see anything or find anything cause it has started to build up it's carbon again, so now they all look the same. And it

Funny thing is i did leave it with them for a day or two to inspect it and i think they may have put something in the coolant, as it is now a different colour and the water rushing sound behind the dash has gone. So it's going to be a while till it over heats again.

Looks like it might have to go down the legal route, lucky i have a good mate who is a lawyer and can write nice letter at minimal cost.

[PhilipA]

Probably Irontite.
Ie a sealant for small block/head leaks.
Regards Philip A

[baz]

It was number 4 cylinder that looked steam cleaned and had some rust on the plug, and after having the coolant replaced it did overheat twice with the light coming on. The water rushing sound was still there after the flush but after having it with the dealers mechanic, the water rushing stopped. Funny hey.

I'm going to have the coolant flushed again today, and see if i can get it to overheat again, being that the additive should be flushed out. Maybe whatever they had in it got rid of the air lock and hopefully after the flush the gases can escape again so i can prove the fault.

[baz]

Quick question on this again.

If we do pull the heads of now, given that the carbon has built up again, and it hasn't overheated, will we be able to visually diagnose this, or would the block need to be sent away for pressure testing?

And given they put some additive in the coolant to try and hide the problem, would this show up under pressure testing? By the way i've had the flushed again to get rid of this, and sometimes you can hear the water sound again.

Thanks for all your help on this.

[PhilipA]

IMHO, if its not showing any symptoms, then its doubtful you could diagnose it.
I take it that the "dealer" is a used car dealer, such as "Dodgy Bros", not a Rover dealer.
I do not know whether a flush would remove "stop leak "stuff. Maybe someone with more experience can answer.
Regards Philip A

[baz]

Thanks Philip A, thought as much. I'll keep you all post on the legal route. But looks like i'll be up for a rebuild, so might as well get a new short motor and do i properly and clean everything else while i'm there.

Geez i still whish i had my 89 RR, still so reliable. It now lives a stress free life on Moreton Island full time, whish i could could do the same!!

[Blknight.aus]

a proper flush will remove the goop, IT will also remove core plugs, welsh plugs and any brass taps you forget to take off...

most places only do a hot flush if your lucky tho...

[PhilipA]

It just happens that the latest LRO has an article on a Disco with exactly your problem.
The way they tested was to take the cylinder to TDC, lock the crank with a socket and bar.
They then used a leakdown tester to pressurise the cylinder to 6-8Bar, and bubbles came out of the radiator.
Simple. whether it works with yours if it has sealant is another matter.
Regards Philip A

[baz]

Hey thanks Philip, is LRO Land Rovers Owners Monthly? What year disco were they talking about?

Do you have a copy that you could scan or fax to me? If not i'll see if i can get my hands on a copy somewhere.

RACQ did a leak down test on Cylinder 4 with not much luck. maybe because of the **** they put in it.

[PhilipA]

Its Land rover International, April 2007 edition which is currently in Newsagents.
PM me your email address and I will scan it for you.
It doesn't really add much.
Regards Philip A

[PhilipA]

Scan Files sent.
Regards Philip A

[baz]

Thanks Philip, much appreciated.