Sort of kinda intermittent high pitched whining noise...?

This has me stumped.

Just over the last couple of months, and only maybe once in every 5 or 6 times I start up my XJ900 I can hear a high pitched whining noise coming from somewhere on top of the engine either, in my guess, from maybe the top cam chain guide or perhaps a small air leak from the intake manifold. I haven't had time for a detailed inspection and when I do have time the noise insn't there. When it is there it is audible around the idle to 2500 rpm mark.

At this stage I'm only a little worried it might be something serious but the fact that it doesn't do it all the time makes me feel a bit better. This is not a clickety clack noise like valves/tappets etc., it's a smooth high pitched sound. When I do hear it I switch off the engine, restart and...IT'S GONE!

Anyone with a suggestion (be nice guys)...

Thanks.

 

Re: Sort of kinda intermittent high pitched whining noise...

Red Centre,

My high pitched whinning noise was also intermittent. It was unfortunately for me the starter motor as a result of a stuck starter clutch. Perhaps next time you hear it, you can quickly check the starter and see if that's it.

Most people have been able to free up their clutch by flushing out old oil, but unfortunately for me I had to strip the engine to find a bolt in the starter housing was loose and had jammed the whole thing up. At least it didn't cause much damage.

oby

 

Re: Sort of kinda intermittent high pitched whining noise...

Thank for the feedback.

I think you might be right. It's a bit hard to pinpoint the sound but it certainly sounds mechanical rather than an air leak.

Might take the starter off and just spray some lubricant around all connecting moving parts.

Cheers - Thanks for the help.

 

Re: Sort of kinda intermittent high pitched whining noise...

I also have this exact issue with a high pitched whining noise from the top end on my 82 xj550 maxim. Mine however only does this when it is hot. On cool days when the engine temp stays low it doesnt do it, but on warmer days its quite noticeable. The noise appears to be comming from the center of the intake cam\cam cover area. Have not had the time to take it apart to see what it might be though.