Another M54 Noise

C

cj10jeeper

Lifer
 Lichfield, England
Seem to be going through a batch of noise issues. Probably as I become aware of each as I fix the last and things happen in batches anyway, especially where there’s a lot of development on the car.

Cured the exhaust touching its own mounting bracket when really hot that caused a squeak and now having fixed the whistling intake and removed that noise, it leads me to the next one that appeared on the Saturday evening of the Lakes event.

Those hanging over the bonnet were aware of a top end rattly clattery plasticky noise. This has now worsened quickly to a point of being annoying and very audible, but not worsening further despite 500 miles last week..

Done the usual stethescope piece to track it but can't identify anything obvious. Found the idler pulley (deflection pulley) a bit loose so replaced that as an obvious, but not that 
I'm certain it's peripheral and not engine. Tempted to think water pump?

Symptoms:
Appears once the engine is slightly loaded i.e. in gear held on brakes or gently pulling away, forward or reverse.
Never does it on idle or free revving of engine
Stops once the speed rises or load increased/decreased, so basically sounds like a bag of nails while gently driving out of the garage and housing estate.
Not temperature related.
First thoughts are idler pulley(or belt tensioner), alternator V belt, water pump?
Anyone had any of these go as they seem robust engine and my X5 has clocked near 100k on the same engine with nothing like this?
 
As you mention driving slowly in all your noisy examples, don't you think it could be something like the dual-mass flywheel area?
 
You have prob already checked this but the engine cover can make an annoying noise they have some sort of gromet type of thing underneath think thats how it was described to me and if any are missing it can buzz and rattle.
 
Guys 3 good suggestions:
Dual mass - not looked at it at all nor had I considered that
Engine cover - possible as it was removed for servicing just before the noise started
Water pump - always a good bet, especially if your made similar noises. Sort of where I hoped it was NOT from...lol

Will be out there later to have a look
Thanks
 
Update.....

Found it was the lower deflection pulley. As above I'd replaced the upper one, but while in for it's MOT today the guys could get better access from underneath and found that the lower pulley, while not loose squarked when turned. They had no time to get a new one, but as a favour greased it up and presto - noise gone.

I'll order and fix a replacement at the weekend.

Just pleased it's a pulley and not a waterpump and al the dismantiling that woudl entail :thumbsup:
 
Surprisingly just below the upper one.... :poke:

Tricky little critter to see, located between water pump and alternator. Just an idler pulley that keeps the belt wrapped fully around the driven pulleys
 
Well my back ordered lower deflection pulley arrived on Thursday so fitted it today to complete the rebuild.

Just to show that CJ doesn't get it right every time :thumbsdown: - stripped half the car to get access to the lower pulley. cowlings, airbox, pipes, etc. so far so good.

Managed to round off to torx bolt by accidentally using a size too small and then the correct size would not fit. :headbang:

Quickly decided to chisel the pully to bits as it's only plastic and could them use stilsons on the 'bolt head'. Did a fine job of that, only to find the pulley is mounted on a forward a rearward facing pair of bolts on a separate mount and I could have just unbolted that. Removed that to the bench in 2 mins, old pulley off and new one on.

Then took me 15 minutes to work out the V belt routing as the first couple of times I had a lot of spare belt left. :cry:

Cup of coffee later and got may act together - all sorted and tidied up, rebuilt and tested, but turned a 15 minute job into an hour..

Good news is my engine is now near silent of whistles, squeaks, etc. and the scratches in my hands from working like a gyno down the front of the engine, should be gone in a couple of days.
 
Reading this thread made me think it'd be useful to take an audio recording of engine noises, could build up to be quite a useful reference for people...

Second thought (I must have had too much coffee today) is that there's some useful little audio analyser apps on smart phones nowadays (Audalyzer on Android or oScope/Signalscope on the iPhone) which maybe would be useful to identify engine noises? or at least a healthy engine from a non healthy one...
 
Siftah said:
Reading this thread made me think it'd be useful to take an audio recording of engine noises, could build up to be quite a useful reference for people...

Second thought (I must have had too much coffee today) is that there's some useful little audio analyser apps on smart phones nowadays (Audalyzer on Android or oScope/Signalscope on the iPhone) which maybe would be useful to identify engine noises? or at least a healthy engine from a non healthy one...
Click to expand...

:poke: John, Second thought - you had too much coffee :)
 
Oakandacorns said:
:poke: John, Second thought - you had too much coffee :)
Click to expand...

I had another thought - the vibration sensor could be useful to get some sort of real-world comparison before and after swapping tyres, run-flats versus non-run-flats.

But as you've mentioned it, maybe I should just cut down on coffee :P
 
Siftah said:
Oakandacorns said:
:poke: John, Second thought - you had too much coffee :)
Click to expand...

I had another thought - the vibration sensor could be useful to get some sort of real-world comparison before and after swapping tyres, run-flats versus non-run-flats.

But as you've mentioned it, maybe I should just cut down on coffee :P
Click to expand...

:rofl: What about feedback from car from run-flats versus non-run-flats? :poke: I hear run flats give a better response (even though one puts up with tramlining)

I've got a thought! - What about sensor for radio reception of stubby versus non-stubby?? :fuelfire:
:)
 
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