Strange Noise Possibly from S/C?
 

Hi All,

First time post here and I know this is a little unorthodox but I actually have a 4.2 s/c Range Rover which I believe is near as dammit the same engine as the xkr.

Unfortunately this is pretty rare in the Range Rovers so there is a lot less knowledge of them in the relevant forums so I have often lurked around here looked for answers.

Anyway I am at a bit of a loss and really hoping you can offer some insight?

I had a vacuum leak coming from one of the intake duct seals. I initially thought I could get it out without removing the elbow so stuck a screwdriver between the elbow and the cooler and needless to say it didn't move. I then found and followed a diy someone did on here and torqued etc, so removed the elbow changed the gasket and changed both ducts.

I put it back together and she now sounds like this and I'm panicking a bit now...
Warm up initially:
Slight Rev:

I then took the elbow off to get some pics of the internals of the supercharger not sure if that all looks good?:
https://cimg5.ibsrv.net/gimg/www.jag...ee3387a8f.jpeg
https://cimg6.ibsrv.net/gimg/www.jag...2a17ad6b9.jpeg


Finally I ran a fuel trim check and they are right up at 22 for both banks on idle...

Any ideas id be mighty grateful!

Many thanks

@DanWilderspin, If STFTs are very high at idle and throughout the range, look for vacuum leak(s).

Thanks for the reply - it was the long term I believe is it still the same course of action? I am going to get a smoke machine in the next couple of days if so

I've never done this myself, but I've heard that you can take a propane torch (no flame, just the gas) and run it around inside the engine bay. When the propane gets sucked in through the leak it makes the engine RPM change.

I've used starting fluid to do that ^ ^ ^ ^ ^, but never propane.

I just listened to the videos for the first time. I was in bed last night and didn't want to wake up my wife. It sounds to me like there is something vibrating in the air stream. Vacuum leaks usually make more of a whistling sound, at least in my experience.

Check this thread including a hiss video
It may help understand your situation WRT vacuum leak

Thanks chaps - reverend - what do you meant vibrating the airstream? What kind of things? Bearing on charger on the way out? Is 20ish on long term trims high for idle? Does this indicate a vac leak as well maybe?

Also Dannyj which thread are you taking about?

thanks

Sorry i missed the link

https://www.jaguarforums.com/forum/x...-inlet-175247/

Hope it may help

Ok just popped out now to have a look at pcv etc nothing obvious :-( made a couple of videos looking around the back of the engine off and the front when on if that makes things any clearer?


Any thoughts? Cheers

I believe a member here make a smoke machine to find vacuum leaks. There is a YouTube video on how to make it for about $40

Ok thought I’d better update nobody likes a post which is not finished https://www.fullfatrr.com/forum/imag...icon_smile.gif

So had my mate round who’s a bmw mechanic of 20years. He borrowed a smoke tester and there were two leaks one tiny one from the loose solid plastic pipe I put a video of and then from the pcv it was leaking all out the top of the circle (not loads but a bit. Taped it up to test it was better and he then listened and told me the noise was a knackered alternator... what are the chances
Of everything going wrong as I change one little intake duct. Going to order a denso from Dan Monday I’m off all week so should have a go at fitting doesn’t look too evil and will update...

Just to confirm after changing the alt and the pcv (greats fun job the alt) the noise is gone and my ltft at down to 10 and 5 and I thinking that due to the leaking brake booster hose but accidentally got the wrong side through so hopefully can have it good as gold then.

Cheers for the suggestions