Head bolts loose? And other questions

Hi all, I recently picked up a cheap 10P D2 with 240k miles that was pressurising the coolant. From a cold start you could remove expansion tank cap after 5 seconds of running and there would already be a lot of gas to release.
So head is now off and I havent cleaned it up yet, but the thing that seemed odd to me was the head bolts didnt seem very tight. I was using an 18" bar to undo them and they just didnt feel like I'd expect (I haven't had a TD5 head off before and didnt realise just how long those bolts are)
Engine had plastic dowels fitted, 1 was broken but that could have been me and a 2 hole MLS gasket with no obvious failure but everything is covered in oil so I havent looked closely yet.
I could see small cracks from the glow plug holes, but these head away from the injector and I assume are from the shallow entry angle.
I should say it seems likely that someone has been in here before me (3 snapped exhaust studs, 1 missing inlet bolt and a slightly mangled cam sprocket)
Anyway I'll get the head cleaned up and checked by a local engineer who knows what he's doing, but does anyone know if headbolts loosening is a thing with the TD5?

They never seem tight undoing them. Nothing more than a short handle ratchet is needed to undo them normally!

tom1979 said:

They never seem tight undoing them. Nothing more than a short handle ratchet is needed to undo them normally!

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Damn I was hoping I'd found the problem

You probably have if one of the plastic dowels was not right. Make sure to replace with genuine steel dowels

tom1979 said:

You probably have if one of the plastic dowels was not right. Make sure to replace with genuine steel dowels

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Eleswhere on this forum you and the OP will find the full SP as regards dowels. But as a basic rule of thumb, plastic should be replaced with plastic and steel with steel.
Others will hopefully be able to find official LR notice about this.

Or maybe me.
See post #14

Others disagree obviously, after all, it is a forum!!

Stanleysteamer said:

Eleswhere on this forum you and the OP will find the full SP as regards dowels. But as a basic rule of thumb, plastic should be replaced with plastic and steel with steel.
Others will hopefully be able to find official LR notice about this.

Or maybe me.
See post #14

Education in vacant oil!

Afternoon all I have a basic understanding on mechanics but this has got me a little stumped. bought a breaker 10p TD5 with a knackered chassis and head gasket gone. The engine still ran fine albeit head gasket failure, so I figured might as well attempt the head gasket and possibly sell on...

www.landyzone.co.uk

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Always replace with steel. Land Rover Service Bulletins can be interesting at times but are not always correct. Nobody has ever had any issues replacing with steel, and no independent specialist would ever use plastic dowels.

The bulletin is attached here.

tom1979 said:

Always replace with steel. Land Rover Service Bulletins can be interesting at times but are not always correct. Nobody has ever had any issues replacing with steel, and no independent specialist would ever use plastic dowels.

The bulletin is attached here.

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Can't open this for some reason but I suspect it is the same one as the one in post #14 in the thread I linked to.
Not all LR engineers agree with you.
James Martin for one.
Although he is no longer posting.

If you look at #19 in that thread you'll see I had a lengthly conversation with Turner Engineering about it, and they have had no issues either. Nobody has ever given a specific reason for fitting plastic dowels other than quoting that technical bulletin.

tom1979 said:

If you look at #19 in that thread you'll see I had a lengthly conversation with Turner Engineering about it, and they have had no issues either. Nobody has ever given a specific reason for fitting plastic dowels other than quoting that technical bulletin.

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I'm not going to argue with you as this always happens.
Simply pointing out to the OP that there are opinions on this, LR's and then other's.
And yes I read the whole thread, ages ago.

Just like some say you can reuse the headbolts and others say you can't.

But a tiny little bit of me does wonder what anything plastic is doing in an engine!!

Stanleysteamer said:

But a tiny little bit of me does wonder what anything plastic is doing in an engine!!

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Nobody at LR ever wondered that, they went on to make plastic inlet manifolds

tom1979 said:

Nobody at LR ever wondered that, they went on to make plastic inlet manifolds

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Idiots!!

Well I looked again at the dowels again, I likely broke one but both of them had a link where the head has obviously moved.
Next bit of fun, this must be why you don't reuse rocket shaft bolts

Kev12 said:

Well I looked again at the dowels again, I likely broke one but both of them had a link where the head has obviously moved.
Next bit of fun, this must be why you don't reuse rocket shaft bolts

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Wtf man

tom1979 said:

Always replace with steel. Land Rover Service Bulletins can be interesting at times but are not always correct. Nobody has ever had any issues replacing with steel, and no independent specialist would ever use plastic dowels.

The bulletin is attached here.

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But the bulletin doesn't exactly say that.

"AFFECTED RANGE:All Td5 derivatives within VIN ranges: Discovery Series II (02 Model Year) 2A 736340 to 3A 793895 Defender (02 Model Year) 2A 622424 to 3A 647705

INFORMATION: If a cylinder head is removed from a vehicle in the above VIN range, the plastic dowels must be replaced with new specification steel dowels, which are now available from Land Rover Parts.
CAUTION: Td5 derivatives 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."

I dont know but I would be careful.

J

marjon said:

But the bulletin doesn't exactly say that.

"AFFECTED RANGE:All Td5 derivatives within VIN ranges: Discovery Series II (02 Model Year) 2A 736340 to 3A 793895 Defender (02 Model Year) 2A 622424 to 3A 647705

INFORMATION: If a cylinder head is removed from a vehicle in the above VIN range, the plastic dowels must be replaced with new specification steel dowels, which are now available from Land Rover Parts.
CAUTION: Td5 derivatives 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."

I dont know but I would be careful.

J

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And this is exactly the point I was trying to make.
But the bulletin is up there for all to read.

And argue about!!

tom1979 said:

They never seem tight undoing them. Nothing more than a short handle ratchet is needed to undo them normally!

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And this always makes me wonder why the old school way of tightening headbolts, running the vehicle for 100 miles then retightening, went out of fashion.
I know this doesn't apply to stretch bolts, but can't help thinking that they have only gone in for all this lark cos they don't want the labour charge etc for having to retighten.

That LR bulletin seems quite clear to me, only fit steel dowels (to replace the plastic ones) in the given range. Anything before that range don't replace plastic with steel.
Does anybody know if all the engines after the range listed, are fitted with steel dowels ?

Stanleysteamer said:

And this always makes me wonder why the old school way of tightening headbolts, running the vehicle for 100 miles then retightening, went out of fashion.
I know this doesn't apply to stretch bolts, but can't help thinking that they have only gone in for all this lark cos they don't want the labour charge etc for having to retighten.

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Who can blame then, when it is 12 hrs labour to remove and replace inlet manifolds on a 3.0 sdv6!
Tdi and td5 simple in comparison.

I have done a TDI before and a daf paccar 4cyl, both of which were simpler than this, but this is ok apart from the snapped bolts so far. It's all stripped ready to take to the engineers tomorrow so I'll see what he says. Thinking I may make aluminium dowels then no one will be happy