Thread: D4 on white smoke!

Originally Posted by Melbourne Park

And when they are glowing they do so due to over 1000 degree C exhaust temperatures. Red hot metal is hot stuff, and if you turn the motor off when the turbo is hot, it appears that todays D4 also turns off the oil pump. So then, the bearing heats up and cooks the oil. While the synthetic oil will not leave deposits on the bearing due to its purity, it will still degrade from that heat. Once oils would build up carbon on the bearings and the carbon would wreck the bearings - synthetic is not prone to that process - but the oil will still be ruined by the high heat.

Concerning idling and fuel usage - diesels don't use much fuel when idling so its a cheap thing to do.

And another thing - diesel fuel also infiltrate the engine oil as time goes on. So the synthetic oil you spoke about, after you drive the vehicle, gets more and more distillate into the lubrication oil. And that stuff is not synthetic. Some diesel engines appear to increase their lubrication levels as time goes on - due to distillate getting into the oil. So if you don't believe in idling a hot turbo, don't forget that your synthetic oil has now been joined by some distillate which isn't as clean as synthetic oil. Have you seen the colour of the synthetic oil at an oil change from your Disco? Its black - and that black is not due to synthetic oil break down. Its due to distillate. I suspect distillate could leave contamination on the turbo bearings if I turn off a hot turbo and then cook the bearing oil.

I missed a 6th month oil change last year - but I won't this year. IMO oil is cheap stuff. I've a friend with a Porsche diesel and he changes his oil every six months, because he reckons its the cheapest way to keep things young. He's an engineer and races cars too and really, diesel oils have a hostile environment. Just like Land Rover say you do not have to change the transmission fluid until 214,000km, I think its sensible if your vehicle tows or goes up some steep hills on rough tracks, to change the oil twice a year. And idling for a few minutes after some engine work is cheap insurance IMO.

Diesel engine oil turning black is due mainly to soot contamination not fuel contamination. Modern common rail engines don't soot the oil like the old indirect injection engines do which is one of the reasons why the service intervals with them is longer than previous. Fuel contamination of the oil can happen with both diesel and petrol engines too. Synthetic oil will still coke on very hot surfaces - they just resist it a little better than mineral oils. (we have a bit of a issue with our gas turbines at work that coke the bearings because of the heat - and thats with synthetic oil)

So from my data during towing no, nowhere near boost at cruising speed. I only tow 1100kg so not massive. I don't think you'd find any legal tow causing boost during cruise as that would blow mileage to smithereens. Still, no question, more load.
I guess my point was I had a turbo timer on my early turbo cars but I abused them in general and it was warranted.
Now I'm old and a little grey we drive casually and rarely feel we've exercised the car to warrant special attention.
I think I'll struggle to win the over-servicing aspect of another discussion as it doesn't hurt to change oil more regularly, but I think if people did oil analysis they'd be quite surprised how long it now lasts. Saying that, towing is unquestionably more work so if one is towing during a cycle, it's arguable an arduous cycle and change intervals halve.

Originally Posted by DiscoJeffster

So from my data during towing no, nowhere near boost at cruising speed. I only tow 1100kg so not massive. I don't think you'd find any legal tow causing boost during cruise as that would blow mileage to smithereens. Still, no question, more load.
I guess my point was I had a turbo timer on my early turbo cars but I abused them in general and it was warranted.
...

I get a bit uneasy when one talks about "boost" in a diesel. The common rail Ford/Peugeot Land Rover diesel is just like other such turbo diesels - they don't have any type of "boost" limiter. No waste gates or things like that are in their diesel engines. In a petrol engine, wastegates limit "boost" and thereby limit a petrol engine's compression (in order to avoid pre-ignition).

There is some form of variable geometry in our turbines I presume - but the whole point of the twin turbos is to get as much air available into the cylinders inside their designed performances. Pushing in more air into a diesel increases efficiency - it even prolongs engine life. The thing that changes the boost "flow" is the amount of fuel going into the engine. So, when I am towing at 100 KMH, and using 13 litres per 100KM of distillate - there is more combustion occurring than in your vehicle, lets say travelling next to me and not towing anything behind it. Our engine speeds are just the same, but my motor is combusting more fuel, and that is producing hotter exhausts and also more air flow exiting the combustion chambers. And that increased air flow increases the "boost". The boost comes from the amount of fuel being burned that drives the turbos. There always needs to be an excess of air available to the combustion chambers so that when we increase our throttle, the motor gets more powerful. Its not about "boost" in a diesel - its about the amount of fuel being injected.

It would be nice to know though, what the different temperatures of the turbos are across different levels of distillate injection. I don't know their temperatures, hence my caution.

Originally Posted by Melbourne Park

I get a bit uneasy when one talks about "boost" in a diesel. The common rail Ford/Peugeot Land Rover diesel is just like other such turbo diesels - they don't have any type of "boost" limiter. No waste gates or things like that are in their diesel engines. In a petrol engine, wastegates limit "boost" and thereby limit a petrol engine's compression (in order to avoid pre-ignition).

There is some form of variable geometry in our turbines I presume - but the whole point of the twin turbos is to get as much air available into the cylinders inside their designed performances. Pushing in more air into a diesel increases efficiency - it even prolongs engine life. The thing that changes the boost "flow" is the amount of fuel going into the engine. So, when I am towing at 100 KMH, and using 13 litres per 100KM of distillate - there is more combustion occurring than in your vehicle, lets say travelling next to me and not towing anything behind it. Our engine speeds are just the same, but my motor is combusting more fuel, and that is producing hotter exhausts and also more air flow exiting the combustion chambers. And that increased air flow increases the "boost". The boost comes from the amount of fuel being burned that drives the turbos. There always needs to be an excess of air available to the combustion chambers so that when we increase our throttle, the motor gets more powerful. Its not about "boost" in a diesel - its about the amount of fuel being injected.

It would be nice to know though, what the different temperatures of the turbos are across different levels of distillate injection. I don't know their temperatures, hence my caution.

It seems that you getting better fuel efficiency than mine as I had done 15l/100k at 110km/h from Melbourne to Fraser Island last Christmas, it was beautiful drive and didn't even feel the 2 tones of camper trailer behind plus 7 passengers, rooftop tent, much more. That is why still love my D4 after many troubles, it is pleasure to drive even such long distance. I hope my 18" GOE rim would bring more joys once arrive, finger crossed. I also consider if some claim to improve the fuel efficiency by doing a engine tune up.

Originally Posted by Melbourne Park

I had an issue with Lexus service, and after 3 months of me trying to get something done about their Brighton Victoria dealership, Lexus did nothing. Totally hopeless. And Lexus have a reputation for providing good service. A crack in a side mirror - the dealership said it had to be replaced. They claimed the whole unit - had to be brought over from Japan. Over $5,000 to replace it. I took the vehicle to a repairer, who bought the mirror and a plastic bezel and replaced it with labour for $600. The dealership would have done the same but would have charged $5k. Robbery. The same dealership also lied about a supposed issue with another Lexus (an RX350). The girls in the reception area are pretty though.


I also cracked my mirror in the D4 (my units fold back so the mirror costs more as its a different shape) - the cost was $95 inc GST. Quite a bit different from Lexus.

Turbos can go wrong and at least your's did not fail - but if it had of, its not a common failure, and LR don't make the turbos, they buy them in. The same with the solenoid that seems to have caused your problem. I do worry about turbos though - I had a 99 series Turbo SAAB - turbos were unusual then. I still idle down my Disco for a while before turning it off - I don't know how well the turbo bearing oil is cooled after the vehicle is shut down, so I prefer to ensure the temperature of the turbo is gone before shutting down. I remember one night out racing around in the SAAB with a friend in his hot car back in about 1980 at night - we stopped and I lifted the hood on the SAAB - and we were bathed in bright red light - the trees next to the road as well - from the turbo which was glowing red hot metal.

Another approach might be to try another dealer - perhaps your not getting the best service available?

The extended warranty charge is really annoying though ... I do think that LR normally only offer an extended warranty at time of purchase. I think the key is to have a warranty that will take your vehicle to where it can be repaired without much cost. So if your in the Kimberly outback or somewhere, its got to go to Perth - you need a policy so that it won't cost much to get a broken down vehicle to where it can be repaired. My 2014 Disco got an extra 2 years and that cost about $1,000 - so someone is making a big profit from that $5,000 quote of yours IMO. I recall that a big insurance company is behind the LR warranty was Allianz - perhaps there are companies like Allianz who might provide a 3rd party warranty? The fact your's is still under factory warranty might make such insurance more available?

I notice that you are towing too - since you have the Redarc Tow Pro. Not sure if that has been an issue or not. Also I note you are using 20" wheels and low profile tyres. IMO that is a risk in itself off road. 18" are a better bet IMO.

I considered selling my Disco for around $75k and getting a ute for towing - but all up, I'd have got no change from doing that. And the vehicle would not have been nearly as safe as the Disco, or as comfortable, easy around town, or as good a tow vehicle. But if I was doing really tough off road climbing etc., I wouldn't choose a costly vehicle.

Cheers and I hope things go better for you. let us know what 3rd party warranty you settle on ...

MP, I just got back from a 3rd party warranty compare to MLR extended warranty, wahh...........

The Eric policy allows for 200,000 total klms from new, so this means that if your vehicle had 60,000klms when the policy starts, you have 140,000klms to travel over the time period.


The policy replicates the manufacturer's warranty, has no excess or individual claim limits (up to purchase price), is transferable to new owners and can be cancelled with pro rata refunds if no claims have been made. You can service the vehicle at any licensed mechanical workshop or dealer, your choice, and you must continue to service in accordance with the log book schedule.


Eric 5 Star Platinum A Warranty (200,000klm limit)

1 year - $1550
2 year - $1850
3 year - $2185

4 year - $2775
5 year - $2995

And then you read this
ASIC warning to car buyers, extended warranties and tyre insurance a rip-off | afr.com