Hey Gents,

So I have been trying to sort out an issue for the last 5,000 miles. It all started with a strange noise from the engine on my 2012 XFR. Above 3500 RPM with blips of the throttle and at WOT, I would get this loud screeching noise. My Indy and Jaguar dealer thought it was bad supercharger bearings. The Jag dealer was about to replace the supercharger until they saw my pulley

I have had the car for 5k miles since its return from the dealer and have yet to reproduce that screeching noise. However, I have had to add 3-4 quarts of oil in 5k miles, get a fair amount of smoke at cold start-up, exhaust pipes and rear bumper full of soot, stumbling at idle, and don't get full boost of 13.5 (modified)...only get 10.5 - 11 psi. It is acting like a vacuum leak.

Question...could this be from the PCV system? Could the screeching noise have been from a blown diaphragm and now the PCV system is stuck open?

I went by Jag today and they told me the replacement of the PCV is a total P.I.T.A.! You have to replace the whole valve cover (which contains two PCV valves) and remove the supercharger to get to it. Any advice would be appreciated before I just start throwing money at the Jag to resolve

 

there are many wiser than me on this forum, and they will likely chime in but i offer that i don't believe the crankcase is to be pressurized, hence the PCV system(s). yes, there are 2 systems. the driver's side of the car has the low pressure system for boring driving and the passenger side has the more expensive/extensive/complicated system with the oil separators and such. the driver side system connects to intake tube and the passenger system connects to top / rear of throttle body. i suspect the oily mist from the passenger (high pressure) side is what causes our intake valve stems to grow the deposits. I'm looking into an oil separator / catch can system for that side to assist the factory system on the valve cover. no room for it up top so i will likely find a spot underneath can to access when manually draining for oil changes.
my car does not smoke on startup, but does use about a quart every 1,250 miles. manufacturer literature seems to indicate this to be normal usage. i believe most of the "usage" is right up the pass side PCV and right down the intake an into the top side of the cylinder..

 

Wow, well thats enough oil to foul plugs and coat O2 sensors for sure. You really need to get a definite on what's wrong since guessing gets expensive real fast. I don't know where you are in cali but supercharger rebuilds can be done right in So Cal for around a $1k. Removing it is not all that hard if you got time, But the first thing I'd look at is the accessory drive belts and tensioners (for application pressure and pulley operation), screeching and low boost could be signs they could be bad and they are the cheapest things that could be responsible for that problem add to this the fact your screech is rpm dependant, bearings usually get noisey and stay noisey(er). Always check the cheap stuff first and NEVER take the ***********s word as the gosple.
If your SC is truly gone that's the next thing, bad bearing can cause internal air leaks and cost you boost.
I would try a different oil before I tore into the PCV system, Jags AJ133SC PCV system is pretty robust and I've never heard anything really abnormal about its operation, but a quick look into the intercooler would be a better tell and the gasket is reusable.