Disco 4 (LR4) Advise on things to check on purchased Disco 4?

Nodge68 said:

From the broken engines I've seen, there's a problem with them. From what I saw, there was evidence of the main bearing rotating in the cap. This then starved the crank pin of oil, leading to overheating and crank failure.


5w30 is too light for any engine, this gives rise to bearing/ crank contact and wear. Eventually the bearings are so worn, that it's a rattling fit in the bearings, which will also lead to crank failure.
Swapping to 5w40 will improve journal to bearing support, and increase engine life, as well as making the engine sound quiet.

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gstuart said:

Cheers , read a few threads about this where some have changed to 5/40

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gstuart said:

But Also read a few threads ref crank failure where they used both 5/30 and 5/40

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gstuart said:

Thank you for the reply, in that case I would stick with the 5W30. By going up to the 5W40 your putting more stress on the engine than needed. Unless it burning excessively than theres no real need.

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Nodge68 said:

Stress on the engine , what rubbish. It's an engine and oil is it's life blood. If it doesn't support the bearings, then metal to metal contact occurs. If metal contacts metal, then it'll wear out, faster.

The main reason that manufacturers use light oils, is to reduce drag on internal components. The thicker the oil, the more the drag. Reduced drag results in a small increase in fuel economy, but an increase in bearing wear. The manufacturer doesn't care about long term engine damage, as they simply want engine to outlast the warranty.
A 5w40 oil isn't anything old or unusual and is actually an LR recommend grade for the TDV6.

Here's the Citroen oil grade chart, which shows the recommended grades. I can't find my copy of the LR chart at the moment, but it's similar to this one.View attachment 183764

You'll notice that 5w30 and 5w40 are both recommend for our climate, but in my experience, it's always better to go with a thicker oil, especially in summer when ambient temps can approach those of hot climate grade requirements.

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gstuart said:

Thks for the chart , does it matter as I’ve not got a DPF fitted plse

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gstuart said:

Spoke to opie oils ref the 5/40 and this was there reply , they asked if mine burnt oil which it doesn’t

Reason I asked was I had recently bought 5/30 oil and indeed could I go over to the 5/40

@Nodge68 , please don’t think this was being disrespectful to u in any way and know ur extremely knowledgeable and never not taken ur sound advice

Also there’s always the issue of the crank issues but there’s never been a decisive reason why they do it , just seems pot luck

As I’ve seen many D3/D4 owners insuring there discos want for nothing yet still happens

The remapping I feel may have something to do with it but am not knowledgeable enough to really know if it’s the root cause

Hi Gary,

Thank you for the reply, in that case I would stick with the 5W30. By going up to the 5W40 your putting more stress on the engine than needed. Unless it burning excessively than theres no real need.

Regards
Jack

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Nodge68 said:

There's lots of different ideas as to why the crank fails, from incorrectly hardened cranks, to crank being dropped in transit. From my own brief investigation on this, all the engines I've seen with this issue, all have had evidence of main bearing rotation in the cap.

I believe that if the crank is going to fail, it will do so before 100K miles. So in theory, if it gets to 100K unscathed, then it'll be good until the pistons fail at ~400K miles.

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Scerion666 said:

Makes me wonder - is there a kit, or way to prevent the engine starting while turning it over for a few seconds to get the oil moving before it fires up? Wouldn't this protect the crank? Like preventing the injectors working initially?

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Rangie Disco Sportsman said:

Sorry to report I've two RRS's outside with snapped cranks both on over 100K but for balance not all are affected I've had several with over 250k on the clock through with no crank issues. If however oil starvation on start up is the issue they may of course have done 250k with less cold starts than a vehicle with much less mileage doing a lot of short journeys.

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