I have the same experience. Has anyone found a specific issue that causes this?

 

You have 1 of 2 issues going on.

1. Your valve cover gaskets are leaking and oil is dripping down onto the headers and burning off. Pray its this issue! This is an easy DIY fix and the new gasket kit is about $100 bucks. Or if you're not comfortable any mechanic can tackle this for you in 2-3 hours.

2. You could have a cracked / rusted EGR pipe. I had both issues and it took me nearly 2 years to sort it all out. If your EGR tube is shot you can get a new one for around $100 bucks as well, but its buried deep in the back of the motor and is a $1000 fix as I just learned. You could try and tackle this yourself too but its not an easy fix an you need some serious mechanic skills for this repair.

Good luck!

 

Car details are exactly the same?

 

The head gaskets have been just replaced in March. This may have left oil allover the engine body. However since then I drove 600 miles. I also noticed that the oil dipstick shows levels over the top mark. 98 XK8