Member Since: 12 Apr 2019
Location: Ayrshire
Posts: 140
3.0 TDV6 Oil Pressure Warning
Afternoon peeps.
Hope you’re well.
I’ve recently swapped out the engine on my 3.0 RR Sport and got it running again.
One of the many issues I now have is the Oil Pressure Warning light is coming on once the engine gets up to temperature….. 🫣
The Oil and Filter have been changed anyway and I’m awaiting a friend coming round to plug in his code reader.
Just wondering if anyone else has come up against this issue on the 3.0 TDV6 and if so what did it turn out to be? The light stays off after initial start up but as said….comes on once the engine gets up to temperature…..roughly around 20 mins or so at idle….
Thanks 🙏2005 D3 HSE
2010 RRS TDV6
17th Jan 2024 12:32 pm
aixede
Member Since: 22 Nov 2018
Location: Aachen
Posts: 66
Hopefully the oil pressure sensor is defect, I would change this as first
step. Not sure, where you can measure the oil pressure
by using a mechanical pressure gauge on this engine.
This would help to find out if only the sensor is wrong.
In worst case the engine may be at the end of life,
good luck.
17th Jan 2024 6:45 pm
aixede
Member Since: 22 Nov 2018
Location: Aachen
Posts: 66
forgot to mention that a worn oil pump can also
lead to low pressure, when hot.
Again, try measure absolute pressure with a mechanical gauge.
17th Jan 2024 6:49 pm
Last Boy Scout
Member Since: 12 Apr 2019
Location: Ayrshire
Posts: 140
Thanks for the advice.
It seems to have stopped doing it now but will keep a close eye on it.
Thanks again.2005 D3 HSE
2010 RRS TDV6
9th Feb 2024 10:37 pm
Last Boy Scout
Member Since: 12 Apr 2019
Location: Ayrshire
Posts: 140
Now then troops. This issue has reared its head again.
I previously changed the oil filter which seemed to fix it but it has returned.
With the above in mind I done the oil n filter incase it was dirty but this time around it hasn’t made any difference so guessing it may just have been a coincidence before.
Has anyone encountered this issue and if so what did you do? Would the type of filter make any difference?
Just trying to get as much info as pos before I start taking it apart….. again! 🤦♂️
Has anyone measured the oil pressure and if so how did you do it?
Thanks.2005 D3 HSE
2010 RRS TDV6
27th Jun 2024 8:32 am
Discopete
Member Since: 14 Nov 2007
Location: Warwickshire
Posts: 36
I am having the same symptoms with my MY16 LR4 diesel. Occasional oil light on when warm on idle, disappears on higher revs. No oil loss and full. Did you resolve your issue?
29th Jun 2024 9:08 am
Gary_P
Member Since: 03 May 2016
Location: Kent
Posts: 1645
Discopete . Just a thought, as yours is a MY16 I presume it has Adblue?
These engines get oil dilution. Not sure it would cause an oil warning light but could it be that the oil is in fact overfilled? Have you checked the oil level using the service menu?
Member Since: 14 Nov 2007
Location: Warwickshire
Posts: 36
You are correct, it does have adblue. It has done 65,000 miles and had the main cam belt service done by a main dealer 5,000 miles and 6 months ago. I don't know if it is relevant but a few weeks ago a message 'service due in 1900 miles' popped up and then another time 'service due', but not since. However this week the oil light came at traffic lights after a short journey but went out on revving. The next time it came on was on starting a warm engine but again it disappeared after revving. The oil level dashboard check shows full oil and there is no evidence of leaking under the car. What is oil dilution and how does it relate to adblue?
29th Jun 2024 9:22 am
Discopete
Member Since: 14 Nov 2007
Location: Warwickshire
Posts: 36
Just googled oil dilution. Am I right that it has nothing to do with adblue and is more caused by short journeys?
29th Jun 2024 9:47 am
Gary_P
Member Since: 03 May 2016
Location: Kent
Posts: 1645
Yes you are. The reason I mentioned the Adblue is because the engines in the Adblue models (mid 2015 onwards) are more prone to oil dilution.Gary
-------------------------------------------
Discovery 4 HSE 2016MY
29th Jun 2024 10:54 am
Gary_P
Member Since: 03 May 2016
Location: Kent
Posts: 1645
Sorry, just noticed your previous post. Here is what I’ve learnt from the forum. I am no car mechanic/engineer so excuse my explanation:
Oil dilution happens when the routine to burn off the soot in the DPF (diesel particulate filter) doesn’t complete (ie you finish your journey before it’s done - hence more likely to occur on short journeys). The extra diesel delivered to ‘burn off ‘ this soot has to go somewhere. It ends up in the oil sump. This dilutes the oil running through your engine. The car calculates the engine oil quality (dilution percentage) by counting how many times the burn off doesn’t complete. This isn’t an actual percentage but a calculated percentage. One of the criteria for early service warnings is oil dilution. At around 6% ( calculated) the car will call for a service and will start advising a count down as it nears this percentage. (The erroneous calculation of this percentage on early Disco 5 models was the cause of many early service required messages ).
Now I’m winging the explanation a bit, but experts on this forum do advise that Adblue engines are more susceptible to oil dilution, but it occurred in earlier DPF models too. The reason , in my opinion, that cars using Adblue are more prone to oil dilution is because they are all about meeting the Euro 6 emissions targets. Whatever changes they made to DPF burn, engine tune etc made them more susceptible. As I say, I don’t know the detail of why, but it is accepted by people I consider Discovery experts on this forum that they are.
If the engine oil is full after a service and the car does not burn any oil, then another indicator that oil dilution has occurred (in addition to early service required warnings, is that the oil shows ‘overfilled’ on the service menu. But obviously this will take longer if the oil wasn’t full to start.
I hope this helps. Probably nothing to do with your core issue of oil pressure warning light but worth a mention.
Member Since: 14 Nov 2007
Location: Warwickshire
Posts: 36
Thanks for taking the time to explain oil dilution. I am not a mechanic and googling faults just makes me realise how many different types of problems there are. I used to have a LR3 and occasionally the auto box refused to move out of first gear. Restarting the car would fix it for the journey but then the problem would return another time. My wife noticed that the temperature gauge plummeted to zero each time the auto refused to change and it turned out to be a failure of the oil temperature sensor. It was telling the car not to change gear as the engine was too cold. Another member on this site alerted me to this possibility but the main dealer had never heard of it. Nevertheless at my cost (about £100) they replaced the sensor and bingo the problem disappeared!! My current LR4 has, since its last service, been used for lost of long trips (unusually) so I would have hoped that all regen had been done. I am hoping that it is just the oil pressure switch that is faulty as it is a cheap fix. A new oil pump costs more than £1k I think. I am tempted to change the switch myself as it looks simple enough to remove. I can't find anywhere that explains how to replace it correctly. It is a screw in but should it be torqued specifically or require special washers? Any advice or links would be welcomed.
30th Jun 2024 5:30 pm
Tyty
Member Since: 18 Aug 2022
Location: South West
Posts: 81
Tapered threads so no washers required. Looking into the engine bay from the front, it is near the front right sticking up with a single wire going to it.
I would seriously be looking at plugging in a mechanical gauge to ensure you are getting decent oil pressure. At least 0.6 bar on a HOT idle after giving it a good thrash for 20 minutes.
Member Since: 14 Nov 2007
Location: Warwickshire
Posts: 36
Thanks for that. I have found a youtube video of someone doing exactly what you recommend. From what I can see a mechanical gauge is cheaper than a garage diagnostic so possibly worth a try. However being unfamiliar with the mechanics I have two thoughts - does the new sensor have a specific torque when replacing it and if I warm up the car then can I remove the sensor or will oil come gushing out? The youtube video misses out those points.
2nd Jul 2024 5:14 pm
Tyty
Member Since: 18 Aug 2022
Location: South West
Posts: 81
You can drive with the mechanical gauge screwed in, the "sensor" is actually just a dumb switch and does not give an oil pressure reading, it just switches a red oil pressure light on if the oil pressure is below 0.25bar (basically your engine would be toast by the time that oil pressure light comes on anyway as 0.25bar is 3.6psi and thats not good news on a high torque diesel - So in your case I really hope it is just a faulty switch. However if your readings on the gauge is low i'd suggest to stop driving it immediately and looking at a rebuild (new oil pump, new bearings, checking clearances etc).
You can remove the switch with a hot engine switched off but everything will be very hot so personally id just keep the mechanical gauge screwed in on the test run, and swap it over once it has cooled off a bit.
RE Torque for the switch naturally tapered threads are self sealing, can use a bit of PTFE tape to help but 20nm should be plenty.
Another thing that is easy to check is to pull out the oil filter and see if there are any shiny metal filings in the fins of the oil filter. 36mm socket if I remember correctly.
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