Thread: D3 - engine jammed on a highway

Originally Posted by workingonit

So if there were no stange smells or noises over that time, ie about 6 hours, I would think the vehicle was running fine. In which case there was a sudden change in something to stop the engine. To me it is still sounding more like a suddenly rotated crank bearing cutting off oil supply - a recognised problem (wish government was more proactive in consumer protection other than just passing laws and recommending you pay a lawyer to enforce it, class action groan) - see the likes of www.landroverhell. That's why I asked the thread if anyone has bothered to get their bearings tabbed as a pre-emptive measure. I know most won't consider it, unless they are happy to swing spanners. But the knowledge that it might be able to be done gives people food for thought.

In regard to the wrong oil (not my first choice as cause), do others know what the symptoms actually are? Can incorrect oil, 20/50 as discussed, actually seize an engine? I can appreciate the need to run lower viscosity range due to higher tolerances in the engine. My guess would be a gradual loss of power over the time the engine takes to warm everything up and oil to reach max viscosity. But then techno is new to the feel of the vehicle.

Incorrect oil certainly can damage the engine in much less than a thousand km and the closer to the last service the engine was, the more likely the oil is in being a factor (of course if the last service was 50K ago that's an invalid point).

Think about this - the main bearings are a journal type bearing which rely on oil feed from the crankshaft for lubrication. The lubrication system of the crank is designed in such a way that the oil pressure will be fed at a point that will cushion the blow from the cylinder firing down on it. To engineer this system properly you need to know the fluid characteristic of the oil that the engine will be using, as the time taken for the oil to spread out of the bearing shell will be different for different viscosity oils. Too thick and the oil will not spread quickly/evenly enough across the bearing, too thin and it will 'squeeze' out too quickly. This is super important with the TDV6 as it does not have tabbed bearings! It doesn't take much wear for the shells to start moving and eventually rotate.

Seems like a silly bit of engineering - a potential reason for this is the fact that the connecting rod caps are 'cracked' and hence no flat area to rebate for a tab?

$10K seems not bad for a new TDV6 to be honest. A mate of mine has just been quoted $8k to fit a TD42T to his GQ Patrol, and that's not exactly in the same league as a TDV6 (or the same galaxy)

I think all you guys are clutching at straws now. oil that is slightly out of spec is not going to cause a snapped crank...

Originally Posted by Rich84

...

$10K seems not bad for a new TDV6 to be honest. A mate of mine has just been quoted $8k to fit a TD42T to his GQ Patrol, and that's not exactly in the same league as a TDV6 (or the same galaxy)

Yes - the TD42T is much stronger!!!

I agree that 10K is not bad. Time to suck it up, get a new engine and hope the PO is generous enough to contribute to some of it...

Originally Posted by isuzurover

I think all you guys are clutching at straws now. oil that is slightly out of spec is not going to cause a snapped crank...




Yes - the TD42T is much stronger!!!

I agree that 10K is not bad. Time to suck it up, get a new engine and hope the PO is generous enough to contribute to some of it...

Out of curiosity and a bit of the offtopic, how many would be willing to contribute if that happened to the car you've just sold?

Originally Posted by technoplague

Out of curiosity and a bit of the offtopic, how many would be willing to contribute if that happened to the car you've just sold?

Depends on the age and condition of the vehicle. In this case if I was the PO I would probably feel inclined to chip in ~$3k.

All that I've read about main failings of these engines relates to the crank bearings (not wide enough and worst of all rotation over time), or incorrect installation of timing belts. Maybe I've missed it, but read nothing re connecting rod bearings being a prob (although I wouldn't be suprised). Don't understand, as a home mechanic, the term 'cracked' rod caps unless it means they come in two parts.

I've only ever rebuilt 4 cylinder Ford engines. The notch for the tabbed crank bearing sleeves is a simple groove at the edge of one half of the clam. Can't off hand recall in the crank rod bearings were also tabbed. Len Beadell, Gunbarell Hwy, by all accounts cut out a piece of aluminium saucepan to replace a worn out crank bearing in a series and drove the vehicle in that state for years after.

I can only think LRover don't tab the bearings as a cost saving measure in the machining process. Easier to stamp out plain oversized bearings in simple machined recesses and hope clamping force alone holds.

And yes, I don't think a slight change in oil spec would have such a dramatic effect, unless of course the increased viscosity ends up rotating the bearing.

Yes, get a new engine. Probably would contribute.

But again, for all those driving D3's with potential rotating crank bearings, what to do? In 15 years when they are as cheap as a Disco 1 (which I will still be driving) I may get a D3, and the first thing I will do is to notch the bearing crank cap and tap a notch in the bearing to suit. Maybe there will be an after market solution by then anyway.

Originally Posted by Rich84

Incorrect oil certainly can damage the engine in much less than a thousand km and the closer to the last service the engine was, the more likely the oil is in being a factor (of course if the last service was 50K ago that's an invalid point).

Think about this - the main bearings are a journal type bearing which rely on oil feed from the crankshaft for lubrication. The lubrication system of the crank is designed in such a way that the oil pressure will be fed at a point that will cushion the blow from the cylinder firing down on it. To engineer this system properly you need to know the fluid characteristic of the oil that the engine will be using, as the time taken for the oil to spread out of the bearing shell will be different for different viscosity oils. Too thick and the oil will not spread quickly/evenly enough across the bearing, too thin and it will 'squeeze' out too quickly. This is super important with the TDV6 as it does not have tabbed bearings! It doesn't take much wear for the shells to start moving and eventually rotate.

Seems like a silly bit of engineering - a potential reason for this is the fact that the connecting rod caps are 'cracked' and hence no flat area to rebate for a tab?

$10K seems not bad for a new TDV6 to be honest. A mate of mine has just been quoted $8k to fit a TD42T to his GQ Patrol, and that's not exactly in the same league as a TDV6 (or the same galaxy)

HowStuffWorks "How long do crankshaft bearings last?"

I've been following this thread with great interest and researching as much as I can as I'm considering a new or near new RRS and I'm not as mechanically minded as some of you guys. So it would appear that this engine is not as built proof as we all first thought and hoped it was a few years ago?

It also appears that prolonged use of the wrong oil in this engine could be worse than the wrong use of oil in the old TD5?

Not a very common failure but the most common to this engine. More luck ( or lack of it) makes it occur. A guy in UK >350,000 miles and he tows cars on trailers for a living, I would say they are generally robust.

I guess some of the luck may be down to whether its a long haul vehicle or frequent stop starter. Interesting to know the percentage of failures over total production runs.

Some links (hope they work):

DISCO3.CO.UK - View topic - Major Engine Failures - TDV6
DISCO3.CO.UK - View topic - Conrods and pistons for TDV6
DISCO3.CO.UK - View topic - Failed main bearing / crankshaft
2009 Discovery 3 -blown engine 89000km !! - Page 2 - 4x4 Community Forum

Sounds like oil testing should be part of the maintenance routine for the D3, rather than after the breakdown. Makes sense that you cannot see with the naked eye an unusual build up of bearing material when doing regular oil changes - consider backing up some of the oil changes with a chemical test?