Disco 2 After some advice, second opinion

Im doing a Land Rover discovery head gasket, it's actually my dads. It was pressurising
It's got an amc cylinder head, from when my dad has bought it.

We got it sent away for skimming and pressure test which it past etc, i asked the place what size head gasket etc and they said a 1 hole gasket. cleaned the block with wd-40 and wet and dry to get a nice surface

A one hole head gasket was purchased with new bolts, top radiator pipe and thermostat and cap for good measure. The dowels where steel so re-used them, i couldn't get the rear dowel to fit in the head gasket as the hole was oval and wouldn't fit, had to also emery cloth the front dowel to make the gasket fit.

Built it all back up etc, lapped the valves in, but left the rear dowel out, made sure all the bolts whent in nice with alittle oil on the threads.

It's now mixing oil and water and still pressurising, but starts and runs fine with no smoke???

Does anyone have any ideas?

lr_diesel said:

Im doing a Land Rover discovery head gasket, it's actually my dads. It was pressurising
It's got an amc cylinder head, from when my dad has bought it.

We got it sent away for skimming and pressure test which it past etc, i asked the place what size head gasket etc and they said a 1 hole gasket. cleaned the block with wd-40 and wet and dry to get a nice surface

A one hole head gasket was purchased with new bolts, top radiator pipe and thermostat and cap for good measure. The dowels where steel so re-used them, i couldn't get the rear dowel to fit in the head gasket as the hole was oval and wouldn't fit, had to also emery cloth the front dowel to make the gasket fit.

Built it all back up etc, lapped the valves in, but left the rear dowel out, made sure all the bolts whent in nice with alittle oil on the threads.

It's now mixing oil and water and still pressurising, but starts and runs fine with no smoke???

Does anyone have any ideas?

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what year is the engine/vehicle,
head gasket thickness is determined by piston height above block face,skimming a head can reduce distance between valve and head face enough that it also requires you to fit a thicker gasket but if valves and pistons arent touching youve been lucky,
id s its tricky top get gasket sat right without both dowels so head off again and some pics of gasket on block

jamesmartin said:

what year is the engine/vehicle,
head gasket thickness is determined by piston height above block face,skimming a head can reduce distance between valve and head face enough that it also requires you to fit a thicker gasket but if valves and pistons arent touching youve been lucky,
id s its tricky top get gasket sat right without both dowels so head off again and some pics of gasket on block

Click to expand...

Yeah the head place said the head was new regarding thickness and a 1 hole gasket to be used.
Do you reckon i could of been supplied a rubbish head gasket if the rear dowel didnt fit it then?

Luke

lr_diesel said:

Yeah the head place said the head was new regarding thickness and a 1 hole gasket to be used.
Do you reckon i could of been supplied a rubbish head gasket if the rear dowel didnt fit it then?

Luke

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was it originally a 1 hole gasket and did they know that
id like to see some pics, more likely poorly fitted gasket,what age is you vehicle

jamesmartin said:

was it originally a 1 hole gasket and did they know that
id like to see some pics, more likely poorly fitted gasket,what age is you vehicle

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It's a 2002 discovery td5, yeah i told them it was a 1 hole gasket removed and they said use the 1 hole one again as the head pressure tested fine and was straight it was just a skim to create a surface for the gasket to key to.
will upload some pics tomorrow

lr_diesel said:

It's a 2002 discovery td5, yeah i told them it was a 1 hole gasket removed and they said use the 1 hole one again as the head pressure tested fine and was straight it was just a skim to create a surface for the gasket to key to.
will upload some pics tomorrow

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you only skim a head if necessary ie heads warped or surface is marked, but obviously they didnt skim enough off to warrant a thicker gasket

What did you the torque the head bolts to ?

freelance said:

What did you the torque the head bolts to ?

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Stage 1 30nm
Stage 2 60nm
Stage 3 90 degrees
Stage 4 180 degrees
Stage 5 45 degrees

Think i got the image of here from google and it was the same on works autodata, bolting down sequence

Luke

10P or 15P engine? I changed my gasket (10P) with kit from Turners. Came with replacement dowels and everything fitted niceley. Did you replace the head bolts too or reuse the old ones? Do you have the correct head for the block?
Rave is quite clear that heads cannot be skimmed. It has case hardened surface that will be removed through skimming. Jury seems to be out on if this is really an issue, but clearly, you must match gasket thickness with new head height from pistons/valves.
Are you sure you don't have a cracked block?
I'd take it back off and make sure about gasket size and alignment. Definitely need both dowels in place.

CliffordGarrett said:

10P or 15P engine? I changed my gasket (10P) with kit from Turners. Came with replacement dowels and everything fitted niceley. Did you replace the head bolts too or reuse the old ones? Do you have the correct head for the block?
Rave is quite clear that heads cannot be skimmed. It has case hardened surface that will be removed through skimming. Jury seems to be out on if this is really an issue, but clearly, you must match gasket thickness with new head height from pistons/valves.
Are you sure you don't have a cracked block?
I'd take it back off and make sure about gasket size and alignment. Definitely need both dowels in place.

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Hi CliffordGarrett, What differances are there between the 10p and 15p engines, and the cylinder head is an AMC Head aluminium, Yeah the gasket thickness etc is correct, Ive got new dowels and a new gasket from rimmersbrow, the image below is the new dowel with the old head gasket and it's the same on the new head gasket aswell, With out being rough with it the dowel wont go through the gasket, other head gaskets ive done in the past the dowels have'nt been that tight. The dowels fit the head and block, snug fit in the block but very light movement in the cylinder head. Just the same issue before with the head gasket where it's tight on the dowels without forcing the dowels through or using emery cloth to make the gasket fit.

Kind Regards

Luke

lr_diesel said:

Stage 1 30nm
Stage 2 60nm
Stage 3 90 degrees
Stage 4 180 degrees
Stage 5 45 degrees
Think i got the image of here from google and it was the same on works autodata, bolting down sequence

Click to expand...

Next time better rely on the workshop manual than on google or autodata cos stage 2 should have been 65NM

sierrafery said:

Next time better rely on the workshop manual than on google or autodata cos stage 2 should have been 65NM

View attachment 141370

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I will print that of for the rebuild , what do you wreckon about the dowels in the gasket?

lr_diesel said:

I will print that of for the rebuild , what do you wreckon about the dowels in the gasket?

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what about them

I was too scrupulous and have fitted plastic as it was plastic before due to a technical allert which claimed to not fit steel if it was originally plastic within a certain VIN range but from the experience of many owners it seems it's not a problem but i didnt want to risk. IMO the dowels are important untill the head is properly torqued down after that no need for them anyway

All td5 derivatives within VIN range:

DS2 02 MY 2A736340 - 3A793895
DEF 02 MY 2A622424 - 3A647705

Cylinder head locating dowels.

Td5 engines fitted to vehicles within the above VIN range are fitted with
plastic dowels to locate the cylinder head onto the cylinder block.

LRE has intrduced steel locating dowels from the following VINs.
DS2 - 3A793895
DEF - 3A647705

IMPORTANT
If a cylinder head is removed from a vehicle in the above VIN range, the
plastic dowels must be replaced with new spec steel dowels, which are now
available from LR parts.

CAUTION
TD5's prior to the above VIN ranges must not under any circumstances, be
fitted with the new steel dowels.
If steel dowels are fitted to earlier engines cylinder head cracking may result!

jamesmartin said:

what about them

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On The picture ive put on with the steel dowel being tight on the gasket as ive got a feeling that is the issue for mixing oil and water from before

Luke

Hmmm, sorry, just seen this. As I recall from doing mine, I had no issue fitting the replacement dowels. Mine all came from Turners. Specs and tolerances make a world of difference.
As for the plastic/steel dowel debate (?), it seems to me that the common head gasket fault resulting in lost coolant and overheating, is largely a consequence of the head moving,evidenced by sheared off plastic locating dowels. The steel replacements offer resistance to movement which is I guess, why they were introduced. I find it strange that LR say keep the plastic ones in the older engine (risk of head cracking) since that implies the movement and subsequent gasket failure is a built-in fault! Anyway, since you have an AMC alloy head, it's a moot point anyway. I'd just use the steel dowels, and emery cloth the gasket holes a gnats. What gasket is that anyway?