Certainly enjoying my new to me 2006 XKR, Had to do a few things such as install a new steering rack, but that is about all. I'm gingerly testing it out now and on the last several occasions that i asked it to go forth with authority I seemed to smell something a little off. It didn't seem to be a gas smell and not quite a rubber smell, but something in between. Could it be a belt that is slipping? Something to do with the Supercharger as it only seems to do it when it is going hard?

Any ideas are welcome.

 

I get a similar issue on mine, as far as I can tell on mine its a valve cover oil leak when the engine is under significant load that drips onto the headers and smokes, and the smoke rises up almost directly into the HVAC intake. Makes sense to me as oil pressure will only be high enough to force oil out through the valve covers at higher load, especially on these supercharged cars.

Try warming the car up, (find a nice quiet straight road) then do a few hard pulls at full power/boost, then immediately pull over and pop the hood and have a look. You may see some smoke. Try and see where its coming from if you do. Its not too severe on mine but doing valve cover gaskets is on my list at some point. I'm a little concerned cos previous owner did them about 10k miles ago, so i fear the valve cover itself is cracked or warped, but at ~$60 for a set of gaskets and 500 a side for valve covers, I'm gonna try the gasket first lol.

I've noticed that with my oil between the bottom of the dipstick and the mid point it is less pronounced, whereas above the halfway point it is more pronounced. Last time I changed the oil I think I may have overfilled it slightly (I put in exactly what the manual says the oil capacity is... so slightly too much) and hoping I didn't trigger the problem with that.

 

Oil pressure and supercharger boost are not related to each other. The oil pressure in these cars will max out between 2,000 and 3,000 rpm .
After that the pressure relief valve starts opening.

If you install an oil pressure gauge you can see that.

PS: there’s lots of reasons ( like gravity) why the oil may be thicker towards the bottom of the dipstick. None of them mean anything regarding engine operation or health.

A 1/4 to 1/3 inch of oil on the dipstick above the Full mark will not hurt anything on a 4.0 or 4.2 liter Jaguar V-8. It won’t cause aeration or any other issue .

 

Good to know. In any case, I do also get an aroma in my car which I have traced to smoke from the hot header underneath the leak on my valve cover when I've been driving it, so that might be the source of the smell for the OP.

 

Thanks guys. Certainly something to look at.

 

I'm pretty sure it's just oil leaks on the engine that gets hot and burns a little. Mine does it after a strong pull. I just keep checking my oil and topping up once or twice a year or so.

 

How often are you changing the oil ?

Even with our semi-modern cars there is enough combustion chamber blow-by to contaminate the oil significantly over
time. The oil gets acidic when it comes in contact with blow-by gases.

I wouldn’t let oil that’s a year old sit in the engine over an extended period of storage, like over winter. Oil is best changed before storage rather than afterwards.

Oil contaminated as described has enough acid content that it will etch the rod and main bearings, shortening their lifespan.

I’ve sent used oil to Blackstone Labs several times for various classic cars. Cars with as little as 3,000 to 4,000 miles on the oil had enough acid in the oil to cause bearing damage if left in the engine over several months.

Z

 

I change it once a year, normally before 5000 miles or so. When I meant burning oil I meant it leaking on the outside of the engine and burning off when the engine gets hot on the outside. Not actually burning oil internally. I'm pretty sure I don't burn oil internally.

 

Also remember the supercharger has it's own oil source - changed mine at 100,000 miles and it absolutely stank

 

All good responses and appreciated.... Will be doing an engine oil change soon and possibly a Supercharger oil change. I've looked at the valve covers and it is quite possible that oil is seeping out of them. Will keep on eye on it. Thanks guys