Rattle

Author
Discussion

maxmeabh

Original Poster:

6 posts

157 months

Wednesday 23rd March 2016
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Hello to you all,

I have had a rattle for over a year now on my plus four which I am unable to locate. Perhaps someone here might have an idea.
Engine running in neutral, no rattle no matter how high the revs.
Engine running, forward motion and any gear engaged rattle only present above 2000 rpm in hard acceleration but not present otherwise, e.g 3000rpm steady speed.
I cannot find anything loose.
Oil pressure normal.
If it was in the exhaust I would expect to hear it when stationary.
Any ideas, anyone?

NDA

22,334 posts

232 months

Friday 25th March 2016
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A cable or something near the prop shaft? Where does it sound like it's coming from - whereabouts in the car?

maxmeabh

Original Poster:

6 posts

157 months

Friday 25th March 2016
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Front, sounds like it is in or below the engine bay but I can't find any thing loose.

LE52 MOG

128 posts

225 months

Saturday 21st May 2016
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A bit late with this but check tape under bonnet hasn't dried out. Sounds like a rattle and is only present when moving. You will be able tell if paint has rubbed off underside of bonnet along the edge. Lubricate the tape with any sort of oil.

mph

2,344 posts

289 months

Sunday 5th June 2016
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It's not pinking (pre-detonation) is it ?

sospan

2,591 posts

229 months

Monday 6th June 2016
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Check your fanbelt and pulleys.
My Plus8 had a "chirruping" sound under hard acceleration. A noisy belt is a known Plus8 issue. (Rover V8 not Aero BMW)
My belt was ok, I took it off to check. All pulleys were fine, no bearing issues, tension ok.
I cleaned the pulleys and tensioner with brake cleaner on a rag. Set the tension.
Noise gone!
I think there was some slight contamination of the pulleys causing slight slip on acceleration.