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disco 2 v8 liner slip?


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right spent most of the day researching liner slip as my disco has started to consume water and for the first time i have noticed bubbles coming back to the expantion tank

now as much as i like the car if it has slipped liner(s) then top hat block is not an option as it is in my opinion not economicaly viable for a car of this age and mileage i have ordered a top end gasket set from real steel and that will be with me soon but before it gets here and i start to rip it in bits is they any way of telling that i have a liner problem rather than head gasket faliure before i pull it in bits

some of my reading on here sugests that a compression test will be ok for liner slip and show up head gasket fault but other reading suggests it may not

now i have been pulling my hair out about this and also upset a friend of mine who has v8 disco in bits at the moment for a top end rebuild(also consuming water after his wife boiled it ) who thought he would have a gasket faliure as he thought this only happened to 4.6s

the other strange thing with mine is that while it does loose water the expantion tank level does not drop and the first you know is when the heater goes cold followed shortly by temp guage going from middle straight to top and it does this very fast not a slow build up like fast as if you shorted the sensor to earth fast pop the bonnet and exp tank still full top hose bleed screw undone and steam and bubbles come out and exp tank level drops after all presure released usaly takes about 3-4 liters to get level back right and bled up

any help greatly recived

andy

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Only sure-fire way of confirming/disproving 'slipped liner' is a block pressure test, with the engine disassembled -I suppose you could do this with just the heads off.... though I have never tried this myself, as all three of my V8s have never used any water at all :rolleyes: (two 3.9 and one 4.0l :))

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People love to say it's liner slip with any fault involving a 4.0/4.6 block (and 3.9's to a lesser extent), I think it's one of those things that is vastly exaggerated. There are a lot of other things to investigate before consigning it to the bin or performing open-wallet surgery.

Also, although 4.6's still command reasonable money, you could potentially drop a different lump in for not much money at all if you're not worried about ultimate performance.

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thanks for the fast responce

fridge most of what i have been reading today has been posted by yourself and a few others with an equaly large knowledge of the rover v8 and i was quite hoping you would reply as i very much trust what you say from reading other posts

what are the other things to investigate first then please as i want this issue either resolved or passed on to some one else as i just need a motor i can trust so that swimbo can get to work and back without worry of breaking down she is pretty good and will check oil and water but if the water looks good in exp tank then what more can she do i cant expect her to bleed it up like i have to every time it does this (can I?)

i have thought my problems have been caused by leaking at the joint the lpg takes its supply from but i am begining to think this is only leaking due to the over presurisation of the system

oh by the way just in case it helps its the 4.0 not 4.6(were they export only for d2?) 145k on the clock

no misfire (not since new leads 15k ago any how)and runs really quite well for its miles

did cam and timing chain 12k ago was slightly warn but not as bad as i would have expected

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expansion tank often have coolant even though engine may be half empty cold heaters is a classic low coolant symptom the liners dont slip unless seized as liner sits on lip the aluminum bore cracks allowing coolant to run up between block and liner less common now as most that were prone have been fixed,it happened on 3.9 onwards as they have 200 thou less ali bore thickness than 3.5

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i very much trust what you say from reading other posts

If your judgement is that bad you're doomed :lol:

what are the other things to investigate first

I'm sure someone with a bit more D2 knowledge will chime in (at least that's what I'm hoping :ph34r: ) but I would be checking:

- All coolant hoses, pipes, joins, etc. for leaks, damage, deterioration especially the added-in plumbing for the LPG system.

- Radiator condition, check the front and the back as they can look fine from the front but have almost nothing left on the back, or have pinhole leaks.

- Could be worth giving the header tank a coat of looking at, if it's plastic they can split, a mate had one where the seam leaked, but only under pressure when hot.

Ultimately it seems like a pressure test is the way forward, although if you've got head gaskets and whatnot on order then you may just have to have it all apart and see what you find, perhaps post pictures of the bits so the V8 sages round here can cast their beady eyes over them and advise.

I'd suggest you stop driving the car until you've sorted this problem out, continually letting it boil over is just inviting engine damage.

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As fridge says you really need to sort this,the way to find leaks is to pressure test cold.Often small leaks disappear as steam and leave little or no signs,I had a 300tdiDisco in yesterday afternoon which had a P gasket leak - only showed when cold.

LPG piping is a favourite for leaks,I once had a 3.9 in that had 7 separate leaks from the tee joints alone.

I think DII's suffer from underbonnet heat build up too,both V8 and TD5,I see alot more heat related problems on DII V8's than P38's and more on TD5 DII's than Defender TD5's.

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passenger side head is now off and every thing looks fine no washed or steam cleaned piston no faliure points on gasket so hope to find a problem with the drivers side strugling a bit with the bolts on this one but didnt try long as it got dark

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<P>I had 2 engines go through liner slip, both on number 3 cylinder. Removing the plugs after standing over night can show up a problem on cylinders 3,4,5,and 6 as if they are rusty then there is a problem. There is no water in the head by these cylinders so the only way they can rust is by moisture rising from the sides of the liners and not the head gasket. Cylinders 1,2,7 and 8 do have water in the head so it can be either. The only real way to be certain is to have the block pressure tested. Another cause for your symptoms could also be from your lpg system. Where the water and lpg is seperated in the vapouriser can corrode, and the lpg can enter the water system causing the same symptoms as an air lock. You wont smell the lpg in the water as the smell is neutralised by the antifreeze. It is not so common but i have seen it happen twice now, so if your vapouriser is old it could need checking out.<BR>Good luck.<BR>Mark</P>

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Well I have found some slight blowing on a cylinder drivers side but not really bad I will post some pics in a bit but all pistons are crudy not steam cleaned washed or rusty it's nearly all back together now and as I found not much wrong and straight edge on the heads showed them as flat so let's hope I can mend this thing

LPG vapouriser sounds plausible

Also found when blowing things clean the pipe to the rad from exp tank is blocked the little one that squirts in to the exp tank near the cap will have a go at blowing this out again tomorrow but with full compressor power on it it didn't want to clear

Andy

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Also found when blowing things clean the pipe to the rad from exp tank is blocked the little one that squirts in to the exp tank near the cap will have a go at blowing this out again tomorrow but with full compressor power on it it didn't want to clear

Sounds like you potentially have your culprit then, if it can't bleed bubbles back into the header tank it's not going to be very happy and stuff may well airlock.

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