Thought I'd start a new thread for this as I've now got oil pressure readings.

As mentioned in other threads, I'm getting the oil warning light on at idle when the engine is hot. I'm assuming it's coming on due to low pressure. The light goes away when the engine revs rise. To start with, it would go out if I put the gearbox in neutral as the small rise in revs was enough to make it happy.

Whatever the issue is, it must be getting worse as this workaround has stopped working. I now need to put it in neutral and press the accelerator to make it go away.

The car went in to have the oil pressure checked yesterday. They found the following readings (the readings were the same on the old pressure sensor and the new one I sent in with the car)👍

11psi at idle, cold engine
10psi at idle, hot engine
28psi at 2,000rpm, hot engine

He also reported the engine to be "slightly rattly" - on top of the cat/heatshield rattle that I was aware of.

The guy at the garage believes that the oil pressure should be OK with these readings. Does anyone know what the oil pressure should be under various circumstances? I've had a brief look in RAVE but not sure which section it would be in.

From here he's quoted:

£150+VAT to drop the sump, remove the crank bearings and check them over.
£450+VAT to replace the oil pump and timing chain if the bearings check out OK (minus the cost for checking the bearings, so £300+VAT on top of the £150+VAT to check them). No parts required as I've already bought them.

If the bearings turn out to be worn he says the engine then needs to come out, flywheel off, crank out to be sent for grinding etc. Very rough ball park figure of £1600-£1700+VAT for this. He says it's been a long time since he's had to do a job like that and he's not sure off the top of his the cost of grinding a crank etc.

His recommendation from here is to check the bearings first. This makes sense as it's the most easily accessible thing to check.

Before I jump in and kick off more work, do the oil pressure readings give you guys any thoughts on what might be at fault? I trust the garage it's at but you guys have such a wealth of knowledge on these specifically. I've also got a fair bit of time in which to play Internet Detective as he can't fit me in for any repairs until the week beginning the 12th :(

Would you be happy driving around in a car giving these oil pressure readings? Traffic is particularly stressful as the engine speed drops low enough to bring the light on when coasting at 20mph or under.

According to RAVE (General Specification Data, page 3) oil pressure on your engine should be 50 psi at 2,000 rpm with a warm engine so you are low, very low. Oddly, although the GEMS is exactly the same engine as far as the oil feed is concerned, they quote 30-40 at 2,400 rpm with a warm engine. In the old days when cars were actually fitted with oil pressure gauges, less than 15 at idle was considered low and 40-50 psi would be normal when running. Do you have a gauge plumbed in now so you can keep an eye on it? If you have, I'd consider bunging something nice and thick in there in the interim. After my engine was rebuilt at V8 Developments, I asked what oil I should use and was told 10W-50 or 10W-60 if I could get it, the 15W-40 I'd been using was considered too thin. Since then I've used 10W-60 (Castrol Edge, bloody expensive so only bought when ECP have one of their 50% off oils weekends). I can run my engine, switch it off then turn the ignition back on and have to wait for the oil pressure light to come on as it holds pressure for a good few seconds after being turned off.

Considering theage and mileage on your car, you do seem to have rather a lot of problems I would only expect on something with my sort of mileage.

Cheers. I was looking in the engine description section. General Spec Data makes perfect sense though - not sure why I didn't look there.

Since I got it I've been running it on 5W-30 based on the info in RAVE. It seemed to be the closes match for our climate. Perhaps the guys on Facebook that have been telling me how silly I am for having used it are right and I've basically nuked the internals of the engine then.

If this is the case then I have to wonder how Land Rover came to the conclusion that 5W-30 was an acceptable grade of oil to put in their workshop manual. 5W-30 is also what's recommended in the Autodata system used at the garage that's been looking at it.

There's a good chance this will take the car off the road for the foreseeable future.

I wouldn't have expected it to eat the engine in that short space of time. Change it, inspect what you drain for glitter (maybe even cut the filter open?) and stick in 20W50 and see what sort of noises it makes.

I got the car at right around 100K miles and it's just coming up to 140K.

For those 40Kish miles it had 5W-30 in.

I'm not sure if that still qualifies as "short space of time".

I didn't notice any glitter when I took the old oil out but then I wasn't looking for it and it was getting dark outside too (I did in the evening). I do have the old filter still though. I'll see about cutting it open to take a look.

As for the 50psi figure, someone else on the Rover V8 Facebook Group has said that can't be right and would blow out the oil seals. I've no idea what to believe anymore on what the oil pressure should be and I'm no closer to being able to make an informed decision on whether or not to keep driving it until I can get the crank shells checked.

I've just fired off an email to Turner Engineering detailing my issue and asking what they'd expect for oil pressure on this engine.

Lots of people just saying "Put 20W-50 in" but that's not the solution. Something has clearly changed to cause the light to come. Thicker oil might make the light go away but it won't tell me why the light has decided to come on now!

It's an engine that was designed in the 1960's (if not before).OK, so it's been bored and stroked to up the capacity but it is the same basic engine designed at a time when the only multigrade oil was 20W-50. Putting something like 5W-30 in it you may as well have filled the sump with cooking oil, I'm not surprised you've got low oil pressure.

I bought a V12 Jag back from the south of France a few years ago, engine design of similar vintage to ours. After around 60 miles the oil pressure when running was down to 10 psi and falling off the bottom of the gauge at idle. I'd been told it had been serviced before I picked it up so called the garage that had done it and asked what they had put in it. 5W-30 mate, same as we put in everything. Found a branch of Norauto (French Halfords), bought a gallon of 20W-50 and did an oil change over a drain at the side of the road. Oil pressure back up to around 45 psi when cruising and down to 15 psi at idle.

You may have done some damage running on thin oil but if you change it to something quite a bit thicker, chances are it will be fine. OK, it will need the crank grinding sooner or later but even after 380,000 my crank hasn't needed to be ground, just polished and fitted with new bearings when it was rebuilt coming up to 100,000 miles ago.

Quote: As for the 50psi figure, someone else on the Rover V8 Facebook Group has said that can't be right and would blow out the oil seals.

Utter bollocks. Nowhere on the engine is there an oil seal that has full oil pressure behind it. It is possible to damage an engine with too much oil pressure but too much is going to be at least twice what it should be as the damaged is that the bearing shells spread.

Gilbertd wrote:

Putting something like 5W-30 in it you may as well have filled the sump with cooking oil, I'm not surprised you've got low oil pressure.

I get that now. In my defence it was recommended by Land Rover in the RAVE manual. I think it's reasonable to assume that LR had a vague idea what they were doing when writing it :P

Doesn't help me now though...

Gilbertd wrote:

I bought a V12 Jag back from the south of France a few years ago, engine design of similar vintage to ours. After around 60 miles the oil pressure when running was down to 10 psi and falling off the bottom of the gauge at idle. I'd been told it had been serviced before I picked it up so called the garage that had done it and asked what they had put in it. 5W-30 mate, same as we put in everything. Found a branch of Norauto (French Halfords), bought a gallon of 20W-50 and did an oil change over a drain at the side of the road. Oil pressure back up to around 45 psi when cruising and down to 15 psi at idle.

You may have done some damage running on thin oil but if you change it to something quite a bit thicker, chances are it will be fine. OK, it will need the crank grinding sooner or later but even after 380,000 my crank hasn't needed to be ground, just polished and fitted with new bearings when it was rebuilt coming up to 100,000 miles ago.

I suppose it really is worth a try, at least in the short term. Even if it only gets me to the 12th without an engine seizure it'll be worth it.

Gilbertd wrote:

Quote: As for the 50psi figure, someone else on the Rover V8 Facebook Group has said that can't be right and would blow out the oil seals.

Utter bollocks. Nowhere on the engine is there an oil seal that has full oil pressure behind it. It is possible to damage an engine with too much oil pressure but too much is going to be at least twice what it should be as the damaged is that the bearing shells spread.

There's so many different thoughts and opinions out there for this engine. I suppose that's the downside to having an engine that was in production for so long. There's so many people each with different experience of them all giving advice based on their own experience.

I've got people on one side absolutely adamant that 50psi is too high and people on the other side absolutely adamant that 50psi is fine lol

I know the RAVE manual says 50psi but it also says 5W-30 is acceptable!

As a short term fix with the oil, would the 20W-50 mineral oil that Halfords sell be adequate? That's about the only 20W-50 I can think of that I can get over the weekend.

What would be the oil change interval for 20W-50 mineral (assuming it makes the light go away and I continue to run it like that for a while)? I assume it would be fewer miles than with a semi or fully synthetic oil.

Rather than the Halfords stuff, I'd go for this https://www.eurocarparts.com/ecp/p/car-parts/engine-parts/engine-parts1/engine-oils/?521776241&1&cc5_251 as it's A3 SL spec so much higher than the A2 SH that the chart in RAVE recommends. That also means the change interval would be the same 6,000 miles. If you use this weeks discount code the ECP oil will be cheaper than the Halfords stuff too.

I was bought up on older 60s and 70s vehicles and 50 psi was always regarded as good oil pressure, anything less than 30 was bad and anything less than 10 at idle when hot meant you would shortly be searching the local scrapyards for a new engine. But in those days you could get a complete engine for £25 if you went down with a couple of mates and hauled it out yourself......

Not that we're ones for rash decisions or anything....

It looks like we're taking it off the road for a while to give me time to work on it. Besides the oil pressure issue there's a stack of other issues building up. I've been buying parts for various jobs and just never getting around to doing them as I always need the car.

On top of the oil pressure issue I've got ball joints, blend motors, rear axle oil seal, noises from the front axle (starting to seem like it might be the diff), probably worn UJs, headlining is falling off etc. I just have no time to get to any of it at the moment. Taking it off the road means I can work on it more leisurely and it's not a problem if I end up leaving the dashboard for two weeks etc.

So, top of the list for a replacement is a Mazda MX-5 of all things. Went off to see the dealer today and popping back tomorrow.

Gilbertd wrote:

Rather than the Halfords stuff, I'd go for this https://www.eurocarparts.com/ecp/p/car-parts/engine-parts/engine-parts1/engine-oils/?521776241&1&cc5_251

Ended up with Halfords in the end. I ordered the one you linked to and when I went to collect it today I was told it would actually be another 24 hours before I collect it.

As I needed it today I went round the corner to Halfords where they have 20W-50 on the shelf.

I only need it until next Monday when I get the crank bearings checked so it should be ok. It'll get fresh oil in again when the sump goes back on.

Decision has been made though. Even if the crank bearings are OK the car is coming off the road for a while. I'll fix up what needs fixing as and when I get time. Once it's all fixed up we'll see about replacing the Freelander with it.

Having two aging Land Rovers with their associated repairs and running costs was starting to become silly. We need at least one car that we can 100% rely on and we don't need two "big" cars.

Ordered an MX-5 yesterday that should be available towards the end of the month.

The plan is to run 20W-50 and hope the light stays off until the new car comes.

I feel slightly bad now feeding mine with £13.49 Comma 20w-50 from Amazon prime... so much of it ends up leaking out (though thankfully minimal to no marking of territory) I'd be a bit miffed spending too much on it :P

Nowt wrong with Comma! They're suppliers to many better known brands.

I use 10w40 in the Duchess. She does many short trips and cold start protection is better with a 10w.

FWIW opieoils recommend 5w40 but they don't list the ZDDP levels in the specs
https://www.opieoils.co.uk/f/2354/15137/2001/engine-oil.aspx

I haven't had a full geekout for the rover V8 yet but I'm currently using this https://www.commaoil.com/passenger-vehicles/products/view/232 which i picked up in a hurry because it matches the handbook and has decent zinc levels for the old school valve train.

And it certainly sounds like pretty much any 20W-50 is better than 5W-30!

Mazda work quick...

They said it would be the end of the month, maybe even September. Placed the order yesterday and and got a call just now "when do you want to collect? We can do Friday if that's ok"!

I have to say - my engine rattles at idle so much you could mistake it for a diesel. In the 30,000 miles or so I've done since having it (sssh Richard) it hasn't gotten any worse - and it isn't driven about with a light foot all the time. I just try and change the oil every 4-5k to prolong its life. It's days are numbered given it has a water issue with the #6 liner that has been waterglassed... so I won't be too upset or surprised as and when either the cooling system starts giving in again, or the rattle becomes more of a 'knock knock, who's there? cyl #3' situation. It'll pick a really inconsiderate time to do it, I'm sure.

Sounds good on the Mazda - going to be a bit of a different driving position to the RR :)

Really silly question.... if you put 20W50 in it and the light then goes out, AND you're planning on pulling it apart yourself, then is it worth taking it in to get the bearings checked?

Chances are they'll charge you a pretty penny to check them, and probably say they'll need doing etc etc etc along with the sharp intake of breath that garages usually do...

If I were you... save the money of taking it to the garage to start with, take the RR off the road when the Mazda arrives, and pull the front cover and check the oil pump gears first. You're planning on doing the timing chain and sprockets anyway, along with other things, so surely it's at least worth pulling the front cover to look at it first and see if it is a simple thing. I can't imagine the bearings are THAT worn, and besides... you have to take the sump off to pull the front cover, so you can always take one of the bearing caps off yourself to have a look, and post the pics up here for a free assessment...

It's a good point (and one I've considered) but it was just a convenience thing - knowing what point I'm actually starting from. I am still tempted to not get them checked.

I've already had a chat with the garage and told them the plan of taking it off the road whatever the results of the bearing check are. They've no incentive to exaggerate the level of wear in the hopes of a nice big repair bill since they know it's not being repaired there.

If changing the oil brings the pressure back up then there seems little point in spending £150 on getting someone to check the bearings only to find maybe slight wear but nothing worth worrying about.

The verdict is in on the thicker oil.....

The light still comes on. The 20W-50 has made no difference at all!

It's actually kind of a relief! I'd have felt very silly getting a new car if the thicker oil had worked. Now I feel like I actually did make the right decision to take it off the road. There's clearly something quite wrong somewhere.

I think I will cancel the appointment. We made the appointment before we decided to get a new car. It made sense then to pay someone to check it as it was more time critical.

We kept the appointment after ordering the new car as we initially thought it wasn't coming until the end of the month or even September. At that point it was was still fairly important to have it checked ASAP as I'd need to use it until the end of the month. If it came back as bad news I'd have needed to sort a hire car etc.

As we're now getting the new car on Friday all time pressure has been removed. Now my only concern is it lasting 3-4 more days :P

It should be ok. There's still no discernible knocking or noises. If any develop then surely that's what the volume knob on the radio is for!

Time to get your green flag upgraded to full recovery.....

This whole viscosity thing and oil behaviour inside the engine is monumentally complicated.

Quite a good introduction here https://www.kewengineering.co.uk/Auto_oils/oil_viscosity_explained.htm .

Fact is once the engine is up at running temperature there is very little difference in absolute units. Probably the major difference in the engine itself is the oil film thickness needed to support the load. Thin oils tend to squidge out of wide clearance bearings whilst thick oils can't get in narrow clearance ones. The actual load carrying film is generated dynamically by the spinning bearing. The effective pressure is huge!

Oil pressure is more a measure of the internal leakage in the pump. If its high enough you know there is enough oil getting around the motor to fill the feed galleries so oil can be swept out into the bearings. If its too low then you can't be sure the galleries are full.

These days with all the modern additives viscosity is more a proxy measurement than a statement of actual lubrication ability. Its arguable that the only thing where viscosity is directly important is in defining the ability of the oil pump to actually deliver enough of the stuff to the right places. Unless the motor is completely knackered if the pump can push enough oil up to the various bearing feed drillings to keep the hydrodynamics fed even an too thin oil will do the deed. Of course if the oil is too thin the bearings need to be spinning faster to build up a thick enough film inside the bearing.

Clive