Burning Oil occasionally

[sheepy]

I'll try this one on here rather than "Jaguar" because I don't think it's Jag specific:

The car in question is an XJS with the 3.6l A6 engine (straight six).

A couple of times in the last few weeks I've noticed that when / if I push Jaggy towards the red-line before I've gone much further than a few miles, I get an amount of smoke coming from the exhausts. The car is up to temperature (gauage shows "N", and auto-choke is off). This smoke does have a blue-ish tinge. If I try the same thing nearer to where I work (eg after ten or fifteen miles), then I can't get the engine to smoke at all. The smoking continues for a minute or so after I ease off.

I've just sat outside the office and hit the redline a few times: No effect. There's nothing coming out of the exhausts (visually) other than normal gases.

If the smoke was white, I'd say it was just water vapour being blown out, but the blue-ish tinge makes me wonder more about things like valve-stem seals or rings.

Anyone got any thought?

Sheepy

[annodomini2]

Compression test will show if its the rings, keep an eye on the oil level. could be either.

[sheepy]

Last night I talked to one of the tutors on the PT Engineering course I'm doing. He said it's almost certainly the valve-stem seals. They will take about fifteen miles to warm-up and function absolutely perfectly, especially on cold mornings. According to him, Jaguar stem seals have a habbit of sticking, and short of pulling the head, there's little I can do.

I think I'll just live with it, and keep the oil level topped up!!

Sheepy

[annodomini2]

if you want to change them without removing the head, take the sparkplug out, ensure the engine is approaching tdc and put the car in gear (to stop the engine turing) fill the combustion chamber with a length of rope (to stop the valve falling out).

free the valve spring, change the seal and refit the valve spring. repeat for all 12 valves and refit cams etc, job done.