Disco 3 (LR3) Engine Overhaul Manual Request
- Thread starter MD0MDI
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Hi
try this , press download after opening each folder
hope that helps
https://onedrive.live.com/?authkey=!AMrvOm7c4l3jJkg&id=4BC2D89C85C7C171!32202&cid=4BC2D89C85C7C171
try this , press download after opening each folder
hope that helps
https://onedrive.live.com/?authkey=!AMrvOm7c4l3jJkg&id=4BC2D89C85C7C171!32202&cid=4BC2D89C85C7C171
Nodge68
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Standard engine rebuild techniques are all that's needed.
The main problem with rebuilding the TDV6 is the lack of replacement components like the crankshaft and shells, although some of the latter are now becoming available. Pistons are available and rods too, but cranks aren't, so that's where the problem is. I'd not grind the crankshaft journal unless if it can be avoided, but it it is ground, the filet radii need to be fully formed and smooth.
The main problem with rebuilding the TDV6 is the lack of replacement components like the crankshaft and shells, although some of the latter are now becoming available. Pistons are available and rods too, but cranks aren't, so that's where the problem is. I'd not grind the crankshaft journal unless if it can be avoided, but it it is ground, the filet radii need to be fully formed and smooth.
hi mate
There were some genuine cranks for sale on eBay @2k , to say the least though would be very sceptical
know there’s plenty of the Chinese copies around
for that kind of money always think buying a complete Jag it seems to be the most favourable , then I would be tempted to pull the heads, replace cams chains, tensioners , hydraulic follows , etc
wonder if that new 19.5 oil pump will stop the crank from snapping seeing it has a higher output ??
Nodge68
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You could pretty much have a steel billet crankshaft ground up for that kind of money.
Nobody would be daft enough to spend £2K on an unknown crank on Ebay, even if it was claimed to be genuine, not that a genuine crankshaft is much to go be.
Most of the TDV6 issues could be solved with some sensible, old school modifications. A steel crack would solve the fracturing issue, and pinning the bearing caps would prevent rotation, even if the oil was starved, not that I believe that's the issue here.
Nodge68
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Those things are very long lived items, simply needing regular oil changes with the correct (not this water thin) oil.
As said. I don't believe the slightly delayed oil pressure is the problem.
Remember the oil Triumph straight six engine in the Vitesse and GT6. Those engines had a shelf draining oil system, which allowed the oil filter to completely empty at shutdown. This then too 10 seconds or more to refill at the next start. Being an old school petrol engine, it didn't start at just over idle, but raced up to well over 2K Rpm from cold with no oil for 10 seconds.
Those engines never spun bearings or broke crankshafts. After 100K miles or so, the bearings were worn out, but that's to be expected under those conditions, especially considering the oils available at the time.
On modern oil, and the short time there's no oil pressure in the TDV6 galleries, it really shouldn't be wearing the bearings, let alone spinning them.
There's more to this issue, to which I have a hunch as to part of the cause, but without correct measuring I can't prove my thoughts.
hiya
does seem the crank snaps in the same place each and every time , did u ever get chance to read that full engine report of where that guy had his engine inspected after the crank snapped
as indeed all reports have found the shells spin, blocking off the oilways and crank consequently snaps
Nodge68
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Yes possibly. Was this were his investigation found that the filet radius wasn't correctly formed? If so then yes I read the report and would have thought the same thing myself. Crankshaft failure can attributed to a few factors. However with modern materials and manufacturing techniques, it really shouldn't happen.
The very fact that all these crankshafts fail in the same place, in the same way, shows there's a definite manufacturing fault it that point.
The filet radius is a vital part of the crankshaft, as it reduces the chances of cracking across the journal. Years ago crankshafts were made of cast iron, which was then machined to the required tolerances and bearing dimensions. Where the crank web meets the journal, large rolled filet radii were used to eliminate stress raisers.
Most modern crankshafts (including the TDV6) are forged, so are inherently more robust than a cast iron cranks of old. However stresses can be formed between the crank pins and webs, due to uneven and rapid cooling of these parts in the forge pressing. To eliminate these stresses, the journals need large filet radii, basically smoothing out any potential stress raisers, increasing crankshaft life.
The shells spinning is something different, which is resulting in a couple of possible scenarios. A the bearing spinning in the rod simply makes a horrible noise before the engine is stopped and investigated. The second scenario is the bearing spinning in the rod causes friction. The friction can be high enough to weld the rod to the crank, using the bearing as the filler material. In this instance the crank can stop rapidly, causing it to snap, or the rod to break.
The question is. What is making these bearing shells spin? And what can be done to prevent it.
It's a complicated thing this catastrophic engine failure, but on that shouldn't really happen at all.
I reckon that only happens because there is an oil issue which causes the shells to pick up on the shells then they spin and I reckon that happens because some time in the past the engine has gotten hot, very hot and this is the result many miles later.
Or the crank snaps wiggles around like a prick in a bucket then the shells spin.
Oil change interval on the D3/4 is way to long for such a small amount of oil, which has to work pretty hard even if the car is driven carefully, wifes audi same size engine = 7.7 litres of oil, D3 = 5 litres!
I have noticed a couple of comments lately about suspect injector/s possibly being the cause of the D4, R/R 3.0 SDV6 crank failures? again possible past mistake misfuel etc and again many miles later bang.
Nodge68
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Possibly. Something is relaxing the crush on the bearings, unless the crush was insufficient out the factory?
Agreed. Too little oil, in there for too long.
I've read that too. If injectors are the issue, then I'd have thought that piston damage would be more evident, before bottom end damage could occur.
One guy said the other day he was entertaining the idea it may be an ecu issue causing the injector to fire at the wrong time massively loading the cylinder/piston up.
So it could be a one time event so severe there is no evidence left and people will naturally assume its a component failure without really knowing what caused it.
