low oil pressure on 99 3.9 disco 1

Hello All,

I'm new to this forum so please go easy on me.

Here are some details of the problem:

The car is a 99 disco 1 v8 with 94,000 Km. I have now owned it for 8 weeks.

Around 2 weeks ago I took the car to a Land Rover specialist for a routine major service and the car was returned to me 2 days later still running perfectly.

After another 2 days and ~ 200km the low oil pressure light started flickering whilst driving, i immediately pulled over and could hear rattling noises coming from the engine.

I left the engine to cool off for half and hour then checked the oil level which was perfect. I then tried to restart the engine and the tapping noise remained.

After a 4 hour wait on a tow track the disco was returned to the garage.

3 days later i get a call saying that the car is ready for collection, the fault I'm told was a bad coolant hose which has since been replaced.

The car then ran fine for a further 2 days, then again driving home from work the oil pressure light starts to flicker, I pull over and the same tapping sound is coming from the engine.

The car is now back at the garage where they have removed the sump to check the oil pick up which they have stated is fine and are suggesting a different oil. I am a little concerned with this as surely if there is no pressure with the stock oil then there will be no pressure with any other oil and something must be seriously wrong.

Appreciate any suggestions.

Best regards,

Kevin

Worn oil pump or pressure return valve may be, the original oil was a very thick grade to mask the fault and now you have the correct grade after the service the problem shows it's self.

Hi,

Thanks for the reply.

If the engine runs as normal with the thicker grade oil then is there any chance of further damage or should I just go with it?

Regards,

Kevin

NO... get is sorted there is a problem and any decent LR garage will put the finger on it and advise u. Then you will be able to "blast around" like any other V8 driver. It has excellent low mileage or is that kilometers

if the oil pressure relief valve is like the 3.5 then the plunger gets scored when over heated. There is an improved tadpole type available.

Thanks guys,

Expecting the garage to give me a call today, now I have a few points to talk about and will hopefully have all resolved soon.

94,000 Km, the low milage was really what made me choose this one over the others which I looked at!

Thanks again,

Kevin

Hello again,

Just heard back from the garage, they had tried the heavier grade oil and it was OK for around 45 minutes and then the low oil indication came back on along with the engine noise.

The mechanic does not suspect the oil pump as the failure is intermittent.

He stated that he is about to remove the sump AGAIN and check the bearings??

Does this sound right?

Thanks again,

worn cam shaft bearings or big ends will give this.

Also Be aware that if head gasket blows into valley it will cause these symptoms-oil overheated. Can tell as valley gasket bulges when hot.

Thanks again,

Bearings have now been ruled out, all look in good condition.

The puzzle continues, the garage is going to fit a new pressure sensor but I would assume that there is no problem with the sensor because there is the loud tapping noise.

Best Regards,

Kevin

New pressure sensor installed, of course the problem continues.

The garage are now about to install a new pressure relief valve. I will update again once the new part is installed.

Just a thought, as this fault only occurred after the service is there a possiblity that we could have a bad oil filter or is it possible that a pipe has been blocked by grime from the old oil?

Regards

I would have fitted a new pressure relief valve and overhauled the oil pump as my first port of call after cleaning out the oil pick up pipe and strainer. Thats just the way i would have gone about it. Others opinions may vary.

After a new oil pump and pressure relief valve were fitted (Genuine LR at a substantial cost) the car was again fine for another half hours driving.

The engine temperature then started to rise to around the 75% mark then the oil pressure lamp started to flicker. Switched off the engine to cool for 30 minutes - restarted and then the tapping noise was back. Again the tow truck was out and the car is again back at the garage.

Any other suggestions as my garage bill is already sky high!

Thanks again,

Kevin

My 1998 Disco 1 3.9V8 auto has similar problems. Checked relief valve and it's ok. Has anyone got any other suggestions?

KMurphy20, did you sort your problems?