What happened to your Discovery 2 today?

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Originally Posted by johnp38

Whipped off the rocker cover today to suss tension on head bolts a bit further as not much to lose since I have new bolts and gasket on the way.

30nm all clicked, no movement

65nm all clicked, no movement

85nm 10 bolts torqued up with moderate pull initially then got a click on them, 1 of the 2 that was solid at 70nm other day moved a smidgen more then also clicked. Other 1 of the 2 firm ones didn't move.

100nm 11 bolts moved to the extent I simply didn't pull on them any further as I felt they were now just stretching and torque wrench not clicking,
the 1 firm one didn't budge and clicked the wrench.

The exhaust side bolts were slacker than the inlet side, the front head bolt on inlet side is the one that has kept tension.

What was throwing me initially when I was first losing water with no visible leaks the system wasn't pressurising, then later when checking cold in the morning the top hose was expanding as I removed the cap and I could hear the air whoosh in. I thought maybe the coolant was leaking out and boiling off somewhere and as the engine went cold the leak closed and then a slight vacuum was created on further cooling.

Luckily it turned itself around during the last week and top hose was getting firm after short drives to shops and water usage has climbed to about a litre per 50km so I stopped chasing ghosts thankfully as the diagnosis was easy (I better be on the right path) after testing the head bolts yesterday and today.

Head bolts were done 30nm, 65nm, then 90, 180, 45 degrees when head was done last.

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Has your coolant loss stopped?

Tony

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Originally Posted by TonyC

Has your coolant loss stopped?

Tony

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After I did them up and put it back together I didn't top it up as I had run out of demineralised water.

Drove to coles and did shopping (including the demineralised water) then came back (6km round trip) and it had already built up a bit of pressure that it normally wouldn't, so not cured anything, I only played around to learn not to fix.

Topped up 1 litre but nowhere to drive till tomorrows appointments (about 20k all up) so will get back to you then.

But the bolts have definitely lost their clamping ability and I doubt I have changed anything.

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Originally Posted by johnp38

Whipped off the rocker cover today to suss tension on head bolts a bit further as not much to lose since I have new bolts and gasket on the way.

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Did you use any assembly lube on the original head/gasket fitting?

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Originally Posted by shack

Did you use any assembly lube on the original head/gasket fitting?

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Nothing on head gasket as first time with MLS and followed instructions to letter, just squeaky clean surfaces, and metal locating dowels.

Block threads cleaned out, light oil on bolt threads (wipe with oiled cloth) and oil between washer and bolt head and head and washer.

Followed Elring instructions for tightening.

Great for over a year or more, header tank always good level, no topping up needed except when I played with modding cooling setup to top thermostat and ok after that.

It was ok as well for a while after I replaced the oil cooler and chemical cleaned the oil out.

Only started couple months ago.

But anyways I am putting it down to cheap bolts from Bearmach not going the distance, as I shouldn't have been able to budge them at such a low torque considering the effort it took to do the last 2 angles.

Quote:

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Originally Posted by johnp38

Nothing on head gasket as first time with MLS and followed instructions to letter, just squeaky clean surfaces, and metal locating dowels.

Block threads cleaned out, light oil on bolt threads (wipe with oiled cloth) and oil between washer and bolt head and head and washer.

Followed Elring instructions for tightening.

Great for over a year or more, header tank always good level, no topping up needed except when I played with modding cooling setup to top thermostat and ok after that.

It was ok as well for a while after I replaced the oil cooler and chemical cleaned the oil out.

Only started couple months ago.

But anyways I am putting it down to cheap bolts from Bearmach not going the distance, as I shouldn't have been able to budge them at such a low torque considering the effort it took to do the last 2 angles.

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I've had issues before when not using a suitable assembly lube on the underside of the head bolts, they can tend to "grab" as the torque rises.

On some occasions I've had it grab, trip the wrench, then I've kept going to override it, and it ends up going another 180° before tripping the wrench again.

I am not an engine builder, but Something to consider at least....

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Originally Posted by shack

I've had issues before when not using a suitable assembly lube on the underside of the head bolts, they can tend to "grab" as the torque rises.

On some occasions I've had it grab, trip the wrench, then I've kept going to override it, and it ends up going another 180° before tripping the wrench again.

I am not an engine builder, but Something to consider at least....

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But here we are talking 2 low torque settings followed by finishing off with 3 angle settings, which negates the grabbing issue or a torque setting as the bolt ends up where it should.

And as it required the use of a long pipe on an extension bar to do the 180 and 45 degree angles because my torque wrench did not give me enough leverage to turn the bolts on assembly, it sure as hell shouldn't be able to give me enough leverage to move them now either unless they have stretched/weakened.

The reason I used an increasing torque setting was to see at what tension they were at now, I should not have been able to budge them at all with the torque wrench as it was too short a lever to finish the angle turns in the first place.

The clamping force on a head should be great enough that the combustion stresses are not 'felt' by the fastener.

I understand this angle method makes sense with the appropriately designed fastener, but I feel it may be more an assembly advantage in the factory than it is for any extra benefit to the end repairer.

I would much prefer a re usable fastener tensioned to specified torque settings. Land Rover seems to want to throw every bolt away, even ones that have a finishing torque setting instead of angle. I have had the rocker shaft and injector clamps out a few times mucking around, no issues reusing the bolts and they torque up nicely and don't feel 'iffy'

But I am thinking about ARP lube this time around instead of oil, being done by angle means it should be same finishing tension but perhaps less effort to turn and less torsional stress on the bolt.

I would swap to studs if they weren't so stupidly priced for this engine.

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Originally Posted by johnp38

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I would swap to studs if they weren't so stupidly priced for this engine.

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Do you watch or follow torque test channel on youtube?(highly recommended for a bit of fun, and edumacation on various tools of interest).

Anyhow about a year ago they tested various bolt types(and studs) for heads and the overall effect was that some of the cheapo Chinesiums of Chinese name brand quality were viable alternative to OEM types.
Also that Grade 8 bolts were pretty much comparable too!

In terms of value for money against a proper name brand they were good. Obviously not as strong, but value for money.

Good stuff, if you can't find, I'll try to locate the relevant vid.

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Originally Posted by AK83

Do you watch or follow torque test channel on youtube?(highly recommended for a bit of fun, and edumacation on various tools of interest).

Anyhow about a year ago they tested various bolt types(and studs) for heads and the overall effect was that some of the cheapo Chinesiums of Chinese name brand quality were viable alternative to OEM types.
Also that Grade 8 bolts were pretty much comparable too!

In terms of value for money against a proper name brand they were good. Obviously not as strong, but value for money.

Good stuff, if you can't find, I'll try to locate the relevant vid.

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Found it, ta.

[thumbsupbig]

good watch.
There are two vids about bolts/studs, both relevant, and I watched them when they were uploaded.
So found them again and note my mistake in that the PQY brand were studs, not bolts!(my bad).

now the issue is, can half decent aftermarket bolts be found for the TD5 ????

Studs from allisport are super cheap now days so I use them but I have found AMC head bolts are stronger these genuine Land Rover and can handle more boost

I use arp lube and takes 5min to toque them all down when you do enough head gaskets