Discovery 300Tdi Head Gasket Queries

bewcause it was 2 hole before ,i wouldnt think it was because of make of gasket ,scraping block isnt a bad idea i do it all the time,no4 is obvious place to blow as furthest from water pump,worth checking for rust /scale build up around bore in block,sometimes when you remove coire plug you can see build up hindering cooling

As you say James - YOU do it all the time.It might not be best for someone on an early attempt.With the correct tool and technique,fine,but if one is not so experienced its quite a risk to take,gouging the block face with a chisel or similar.

I thought that many go up a hole in gasket size when replacing,thats why I ask.I wasnt implying that it was gasket type related,indeed I prefer elring.I was merely comparing notes on my own experience,that way knowledge is discussed and shared.

What you say re: No4 blowout seems obvious now that you say it....is such fire damage radiating out from the piston bore,then,related to deficient coolant?

I put a smile symbol there so you know I am not being accusatory or combative - merely asking friendly questions in a friendly discussion

i wasnt been critical 3 hole used as a garage wouldnt know what gasket before hand and many others dont know how to tell whats fitted,a good gasket/paint scraper preferably new so square as good as anything i know to clean block

Aah,I see.So unless there is a skim or evidence of valve or piston strike then go with the same hole gasket?

I myself have for many years used a scraper that I inherited at age 12 that takes single blade rigid-back razor blades,a very good tool.However,in my young days when under pressure and rushing,away from my own tools,I had used all kinds of things as gasket scrapers.....and found out the hard way that it is easy to gouge a block,or especially a head.Now that disability has forced patience upon me I am more circumspect.To myself I think that a good rule of thumb (for me at least) is to use something that will break before it damages the surface being scraped.And as you say,square.

Whats your opinion on hermetite type high temp,high pressure gasket sealants? I have recently seen several matal bearing products claiming to be useful for cylinder head sealing? I remember my father used (green?) hermetite on the BMC and Leyland lorry engine heads he was servicing when I was a child......I seemed to always manage to get it smeared on my clothes as I passed him spanners,much to my mothers displeasure.

on cast iron heads like the red blocks it would be good ,but ali head and cast iron block there is too much movement ,hence composite gasket,

shocker said:

Is that a genuine LR head or aftermarket? I have found the genuines better,suprise surprise.You appear to have the same problem there as the one I just had skimmed,gas blowout at the back of No4.Mine was also an elring gasket,like yours looks to be.

I would be scrubbing that TOTALLY clean with nylon scourer sponges and paraffin and then dry polishing it ,with a very light touch,with a buffing wheel on a drill.THEM you could see if there was any pitting from the fire blowthrough at the back.Then similar clean of the block face,drain water and oil after to flush out any nasties that have dropped down the cavities.A good rule is to never clean the block with anything that would do damage circulating round a running engine,so no wire wool,wire brushes or hard metal scrapers.
Use brake cleaning fluid or similar solvent to clean head and block before assembly,and let it evapourate before.Everything else has been up on here recently,new bolts etc.

Why a 2 hole replacement gasket,by the way?

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Thanks for the advice. Will be going to the shops to buy a few supplies and replacement tools tomorrow, so will pick up a scourer and some paraffin to get it spotless

Why a 2 hole gasket? Because that's what I took off - you can even see it on one of the pictures I uploaded. Surely it's best to put the same size back as you took off? Or am I missing something?

No,not missing something.Its just that a lot of people have been saying to go a size up on gaskets when replacing so I wanted to pick James mind on that.