Oil consumption
 

My v12 is using about a quart of oil every two tanks of fuel... about 600 miles of highway driving at 70 mph... How concerned should I be?

Hi gccch

That Oil consumption seems a little excessive, have you checked for leaks?

I don’t see any leaking heavily from underside of the car. But I do believe I have leaking oil onto the exhaust manifolds because I generally smell burning oil when the engine is hot.

Hi gccch

That could well be what it is then

I agree with Alex.

A perceived "small" weep can dump a huge amount at highway speeds, and hour after hour of running.

Those tappet blocks sound like the culprits, and Greg in France has a write up on his fix, coz to reseal them as factory means HEAPS of stuff off the top of the engine.

Oil switches are also known weepers.

Remember that oil pressure at highway speed is 80psi ++

I have never had a V12 that actually "burns" oil, its always escaping through somewhere.

I would be sorting it as soon as practical, as hot oil on the exhaust manifold CAN ignite.

oil switches? Can you further define what you are referring to please?

The two senders, one for the gauge and one for the warning light, behind the capstan in the V, screwed into to an aluminium casting which also distributes the main oil feed to the valves and cams. I had one start to leak and in 100 km it blew out about an gallon of oil!

OK,

Down the rear of the engine, nearest the firewall, are 2 oil switche.

The LARGE one that is mounted vertical is for the gauge.

The SMALL one mounted partly horizontal, facing the A Bank cam cover is for the Idiot Light.

The large one leaks, and the gauge is mostly unreliable. This is a Smiths Brand sender, and SPECIFIC to Jaguar.

The smaller LEAKS with regular monotony, and is NOTHING exotic, and a generic 1/8BSP, with spade terminal oil switch will fit and work. $6 anywhere. My HE has a Topyota Corolla, OLD model, switch in there, and is just fine. The PreHE has, ???? I forget, something I had in the draw at the time it started spewing oil, and is still dry.

Not easy to change, but very doable within an hour.

Been dealing with this since day 1, done alot of seals half moon seals special seals and forbidden seals. Only seal left is the rear one that you prettymuch need to pull the engine to get to. I use 20w60 oil and if not that then top up with Lucas high milage oil additive. Thicker is better but it still drips on those long drives.

Switch to better oil, get all accessible gaskets and seals done, and ignore it. You see Jaguar knew people would like self-coating rust proofing so they built this feature in...a proper Jag always drips and sprays abit to rust proof itself and mark territory on the garage floor.

Nope ! Mine never leaves even the tiniest drop on the floor.

Oh, it has a few leaks, sure. It's just that the engine bay is so crammed that none of the drips can find their way to the ground :)

Cheers
DD

Thank you all.... I won’t worry too much and will check these switches.

When undoing them, if you have to, be sure to support the aluminium casting against the torque of undoing the switches. If not it can snap off, and that would be a bad idea!

i run mine at one quart low , and oil use is almost nothing.

when full level it goes thru a quart in 300/500miles!
ron