Just to answer a question I missed...why go up a viscosity grade at the hot end. Simply because my experience of using aftermarket rockers and shafts suggests that this is the place that oil pressure bleeds from. Using brand new steel rockers and a new shaft the oil pressure light would come on when hot. I immediately swapped back to old land Rover parts. No light. Quality rockers and shaft are very expensive (£800+) from land Rover so my guess is most v8 s are on original or new but crap shafts/rockers leading to lower than ideal oil pressures.
chris-the-gerbil
Well-Known Member
That's really quite curious. I would be amazed that a fairly small rocker shaft could loose so much oil to drop the pressure off - I would have thought it would be so noisy from wear or just excessive clearances that it would be untenable long before pressure issues became apparent.
Our D2 V8 had an oil cooler for the engine and one for the gearbox.
We ditched the engine oil cooler and run 10W-40 or 15W-40 Diesel oil in them all, three V8's and a Rangie.
Peter
It's true replacement steel rockers are badly made the only reason they make them in steel is because the replacement Ally rockers are so poorly made the pads fall off. The shafts are undersize to. It doesn't take much gap to have catastrophic oil pressure. I've not brought enough varieties to say there all crap though. But land Rover originals are ok but often very badly worn under the shaft.( But still better than replacement)
If any one knows of good(cheap)uns speak out now!
If any one knows of good(cheap)uns speak out now!
Ask Mozz Smith!
I use full synthetic in the Jag but I'd never risk leaving it 30k miles. 10k, yes.
Not really needed, we do tow a lot as regulars will know, but out of the two coolers, we felt that the gearbox cooler (R380) was more important, especially as the engine cooling system was functioning OK. We took the rig to the South of France in 35 Dec C temperatures and it was fine, temperature never moved from the middle of the gauge.
Having two coolers in front of the main radiator isn't good either.
Peter
norseman
Well-Known Member
You could well be right with the first part but I disagree with the second statement - I had a 3.5 RRC, which I sold 9 years ago, that ran well & still had factory spec. compressions at 160K. I obviously didn't know it's service history, but what from what I heard about the PO I doubt he paid out for expensive oil lol. During my ownership it ran on 20/50 mineral changed annually / around 3K.
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chris-the-gerbil
Well-Known Member
Modern oils though are very good - unless you do testing you have no idea. The LL04 I am using for the BMW is within spec still for all markers at 30k, it's getting a bit low on TBN which is what the condition sensor looks at in the oil to decide when to change it - but there is no loss of viscosity, shear stability, etc...
Turboman
Mab An Gov
My disco with 3.9 V8 was on 110,000 miles when I sold it. It is still running like a clock, and never seen anything but mineral multigrade oil in it's life.
I agree with Lister, transmission oil cooling is more important than engine oil cooling.
And not sure why anyone would feel towing a tonne was a big load on their motor. I have rarely towed less than 3 tonnes with a Landrover, and not had any reliability issues.
Turboman
Mab An Gov
Modern synthetic oils are excellent, so good that it is hard to run an engine in with them. I use synth in the Mondeo, which probably has the same engine as in your Jag.
But those engines are designed for synthetic oils. The Rover V8 was designed for mineral oil, synthetics did not even exist at that time.
chris-the-gerbil
Well-Known Member
I don't have a Jag... that's someone else.
As for "designed" for mineral or synthetic - that's a total red herring. Engines are designed for certain tolerances and then an oil which will maintain appropriate flow rates, film stability and shear, shock loading and contact scuff etc is chosen. That can be fulfilled by synthetic or mineral base stocks - the engine wont care.
Turboman
Mab An Gov
Apologies, it is Grrr has the Jag.
Dont agree about the design. Modern synth oils are far too thin for older engines, and so slippery they can lead to glazing of the bores.
Newer engines like synthetic oils, and run more economically and have smaller oil capacities as a result of using such oils.
Colthebrummie
Well-Known Member
I change my oil when it has turned black, regardless of miles or age. Sometimes I even change the filter, but not always.
Col
Col
funrover
Active Member
My old V8s 3.5rrc 3.9rrc ran on 20w50 never had an issue, and they ran like swiss watches.
my other engines 2.25 and 2.6 engines ran on SAE 50 without issue
The current tow pig 4.6 rr p38 runs on shell 10w40, changed every 5k.
my old vm ran on anything i had lying around in my shed usually a mix of 10w40 and SAE 60 lol
i've always change my oils regularly every 5k max and my engines have never let me down.
my other engines 2.25 and 2.6 engines ran on SAE 50 without issue
The current tow pig 4.6 rr p38 runs on shell 10w40, changed every 5k.
my old vm ran on anything i had lying around in my shed usually a mix of 10w40 and SAE 60 lol
i've always change my oils regularly every 5k max and my engines have never let me down.
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