300 Tdi oil pressure warning light on warm engine

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aquaplane

New Member
Posts
70
Location
Mirfield West Yorkshire
Mornin all, the oil warning light on my S reg Discovery 300Tdi, 122000 miles, has started flickering at tickover, but only when the engine is warm.

I'm using Millers Oils 10-30 (IIRC) and it's only 1500 miles since it was changed. I have topped it up to the top mark on the dipstick to make sure there was enough in, it was close to the bottom mark but on the right side of it.

I found this which has some good info on the first page even though it's a year or 4 old.
http://www.landyzone.co.uk/lz/f7/oil-warning-light-44886.html

My first thought was to change the oil and put some 15-40 in but the sticky valve thing referred to in the Defender thread has got me wondering if I'm being too simplistic.

What does the team think?
 
should be 10/40 - even 15/40

it's a posh tractor engine not a whizzy 16v jap sewing machine engine
 
my disco has 5w-50 motor oil since 1991 :rolleyes: it´s now droven 353 000tkm and without proplem. i change oil for living and i just been thinking that is your oil mineral based oil? if it is ´, it can boil with very high temperature, over 130c... oil filter can wrong type also, it have to had valve on bottom inside. i´ve would change the filter first and try.
 
The 10-30 oil is what's specified in my handbook so that shouldn't be the problem, I'm not saying it isn't, but I don't think it should be.

It's been OK with that oil during the summer too, why play up now as it's cooling off, don't make sense to me.

The filter is one I got from Paddocks so I foolishly assumed it would be right. I got 2 at the time and this one is the second one so that should be similar.

Somat has changed but I don't know what.

I'll still try it with some ficker oil in and hope that cures the symptoms without shagging the engine.
 
Pressure test oil from the sensor could be a worn oil pump, I hat one on a truck do that before.

Internal parts worn enough not to give enough pressure on idle, oil gets thinner as it gets warmer and will work through gaps more easily.

As engine speed builds the pump works harder and more oil is pulled through the pump and more pressure is created to turn the light out
 
Firstly I'd do an oil change we always use SHPD oil no need for fancy names we use SHPD E7 or higher grade we get it trade in 25 Litre containers so its not too expensive.

Ok you need to establish weather you have lost oil pressure or if the sensor is faulty.


Oil pressure switch failure is quite common (200tdi) 4 motors here within a year of each other that the oil pressure switch goes faulty. When we pulled the old swith apart the diaphram was punctured.

I would wack in a new switch for the £3 or £5 it will be its well worth while. You could get a pressure guage to be sure but a new switch is difinalty in order!

My own switch got worse until it was on permenantly at lower revs. Typical sign of worn engine however there was no good reason it became worn. No overheating or lack of oil and more importantly no knocking or bad noises or poor performance.

TBH these engines are strong. My old N/A had the wrong oil pump gear. The spigot was half the dia of the oil pump gear bush. (series gear in an early 90 engine) Unbenown to myself it had good enough pressure to put the light out for years until it got seriously seriously hot and cooked itself at a comp all due to us pushing it far too hard no fault of the engine in any way. When we pulled it down the gear was completly wrong, shells were worn and the engine wasn't in the best of nick but we kept it going for a few months until i got a 200 Tdi.

Change oil, I also use Slick 50 never had a problem, others will disagree and think its snake oil each to their own.

Change switch if the light still comes on then you Need to investigate furthur and I would suggest you get a guage to see what Pressure you oil is making.

I wouldn't worry until I had replaced oil and switch.
 
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Firstly I'd do an oil change we always use SHPD oil no need for fancy names we use SHPD E7 or higher grade we get it trade in 25 Litre containers so its not too expensive.

Ok you need to establish weather you have lost oil pressure or if the sensor is faulty.


Oil pressure switch failure is quite common (200tdi) 4 motors here within a year of each other that the oil pressure switch goes faulty. When we pulled the old swith apart the diaphram was punctured.

I would wack in a new switch for the £3 or £5 it will be its well worth while. You could get a pressure guage to be sure but a new switch is difinalty in order!

My own switch got worse until it was on permenantly at lower revs. Typical sign of worn engine however there was no good reason it became worn. No overheating or lack of oil and more importantly no knocking or bad noises or poor performance.

TBH these engines are strong. My old N/A had the wrong oil pump gear. The spigot was half the dia of the oil pump gear bush. (series gear in an early 90 engine) Unbenown to myself it had good enough pressure to put the light out for years until it got seriously seriously hot and cooked itself at a comp all due to us pushing it far too hard no fault of the engine in any way. When we pulled it down the gear was completly wrong, shells were worn and the engine wasn't in the best of nick but we kept it going for a few months until i got a 200 Tdi.

Change oil, I also use Slick 50 never had a problem, others will disagree and think its snake oil each to their own.

Change switch if the light still comes on then you Need to investigate furthur and I would suggest you get a guage to see what Pressure you oil is making.

I wouldn't worry until I had replaced oil and switch.


I agree with Jai. For info the military use 15/40. I would get a new switch from Paddocks or your local car parts place. It takes 5 mins to fit and from my experience (5 discos and 2 switches) it will fix your problem. At least you'll know that it will require further investigation. Unlikely to need oil change to make the light go out, so don't spend money you haven't got to just keep up the service intervals.
 
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