I have the engine cover trays and crap removed from this Engine and suggest others should do likewise, it gets extremely hot...

 

It's designed to run hot.

Your car, though, so up to you.

 

Designed to run hot? Why is there cooling vents on the bonnet?
Nobody engineer's a product to run hot, remove heat, yes.

 

It's designed to run hot but not too hot and the vent may be useful or just vanity.

 

I take it you are not an Engineer <of any sort> ? Heat is a killer and its why the Vacuum lines wrapped in heat shrink are perished and why theres two large holes in the bonnet - I suggest you walk under the Engine of a XKR after its out on a run under a ramp and see how you feel.

To update the fuel trims, I fitted C2P3419 and bodged a 3mm hose to replace AJ811093 as that part is back ordered - I have been looking at the fuel trims as its takes a number of cycles for the LTFT to even out and they are now close to 0 at idle, fluctuating around +/- 1 percent or so. So the Vacuum hose was the source of the lean fuel trim.
I will do a better bodge over the weekend with better quality silicon cut to the correct lenghts as the OE pipe, which I probably do not need anymore

 

 

Hot is better if you are running a steam engine. I took off the engine cover shortly after buying the car. When that plastic hose crapped out fitted around the supercharger I could hear the hissing noise. I too did a "bodge" fix using clear hose. Worked well. I eventually replaced the assembly with the original part.