| Author | Message | ||
     Kevin Lagden Frequent User Username: kevin Post Number: 89 Registered: 7-2009 |
The Shadow SRH19305 has just suddenly developed a strange flapping noise, akin to a piece of paper stuck around the tyre. I have checked under and around the engine bay, listened to the blower motors for the aircon even checked the fresh air flaps under the handbrake, but can't find where it's coming from. It's more apparent for the first 10 mins or so, then gets quieter but still there in the background. I seem to recall a thread somewhere that suggests that perhaps its the speedo cable, but I'm not sure. Any diagnosis from my esteemed RR colleagues out there? | ||
| Geoff Wootton Prolific User Username: dounraey Post Number: 239 Registered: 5-2012 |
Hi Kevin Frayed drive belt perhaps. Does the flapping sound occur at all times, or only when the car is moving? Geoff. | ||
| Kevin Lagden Frequent User Username: kevin Post Number: 90 Registered: 7-2009 |
Geoff Had all the belts changed about 12 months ago. Only when the car is moving | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 503 Registered: 6-2009 |
Kevin, Based upon my memory, but not personal experience, I'd say your initial guess is correct (or at least a reasonable hypothesis). The chassis number/production changes booklet seems to indicate that the transition to electric speedometer didn't occur until the two series cars had already been being produced for a while. Brian | ||
| Jan Forrest Grand Master Username: got_one Post Number: 488 Registered: 1-2008 |
Check the tyre treads for foreign bodies. There could be something stuck in the rubber that comes back out at first only to be pushed in again as you roll down the road. I once repaired a truck tyre that seemed to have a bolt through the tread, but on removal it turned out to be a complete bicycle pedal and half the crank which had entered pedal first! | ||
| Geoff Wootton Prolific User Username: dounraey Post Number: 240 Registered: 5-2012 |
Hi Jan Interesting point that. I had assumed that as the flapping noise goes away after 10 mins that it would not be the tyres, however if there is a foreign body in the tyre then it could be pushed further in as the car is driven, only to reappear when the car is left stationary. Regards the speedo cable, I have a problem with mine but have not had time to address it yet. It makes a clicking/tapping noise, rather than a flapping noise. Also, the speedo needle jumps aound slightly. If the flapping noise was coming from the speedo cable, I would expect there to be some effect on the stability of the speedo needle. Geoff | ||
| Kevin Lagden Frequent User Username: kevin Post Number: 91 Registered: 7-2009 |
I'll take a look at tyres but they are all new, but you never know. I did have a speedo that jumped about but that was also fixed a few years back and seems OK now. Probably turn out to be something quiet ridiculous I'm sure | ||
| Chris Browne Prolific User Username: chrisb Post Number: 114 Registered: 2-2010 |
Kevin, Perhaps something has wrapped itself round the prop shaft - paper, card, plastic bag? Just a thought. Kind regards, Chris | ||
| Jan Forrest Grand Master Username: got_one Post Number: 489 Registered: 1-2008 |
As I've mentioned previously; with jumpy speedos it's all too often a case of poor lubrication between the inner and outer cables. The difficulty in curing this is the fact that speedo heads do not play well with oil (which can creep up the cable) and that some newer cables which are often lined with PTFE which can swell in the presence of mineral oil. The only universal cure I am aware of is to insinuate some micron sized dry graphite granules into the cable, but that's a messy and difficult job without the necessary application tool to blow them into it. You can buy aerosol cans which contain such granules, but they rarely come with a 'straw' to guide/concentrate the spray exactly where you need it to go. Molybdenum Disulphide could be an acceptable substitute in the same format. I haven't heard of it working in this application, but I haven't heard of anyone trying it either. | ||
| Bradley van Ree Experienced User Username: bradbase Post Number: 15 Registered: 5-2012 |
[EDIT: oops, sorry, just re-read the postings and you've mentioned the tyres are new which debunks my ideas... If the tyres are actually new (purchased recently) the below doesn't hold true. If they are 'new' (haven't been used much) the below may be useful. Either way I wrote the below so I'll leave it here. ] If the rhythm of the noise is in time with the tyre movement, with a tubeless tyre, it may be a split tyre. I've witnessed, and had personal experience with, tyres that have a strange short "chuff" sound at low speeds and, as the car increases in speed the sound becomes similar to a 'plastic' clicking (like a plastic card being flicked or if an amount of something tacky is stuck on the tread -- like bubblegum on the sole of a shoe). Provided the car doesn't happen to park with the split in an open position the tyre may not necessarily deflate as one might expect from the description of the problem. In this case the tyre would need re-inflation as if there was a very slow consistent leak which may be mis-diagnosed as the tyre not being seated on the rim correctly. If you're like me with these things the cost of infrequent re-inflating a tyre appears to far outweigh the cost of getting the tyre re-seated and so the tyre never gets to be seen by an expert. At a guess this may explain why the noise changes after 10 mins of drive time... The tyre warms up and the behaviour of the rubber could change. If your tyres are old it may be the tread coming loose or some of the internals coming off the inside of the tyre. Tyres are made up of a surprising number of layers and different materials and exotic glues. If your garage floor is concrete there is a chemical reaction that changes the nature of some of the rubbers in the tyres which has the potential to do odd things. It might be good to have your tyres rotated at a quality garage and ask the technician to check for these things. | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 305 Registered: 5-2012 |
Kevin I note that you entered this query on July 1. Have you sorted the problem now or is it still outstanding. It would be interesting to have an update. Geoff | ||
| Kevin Lagden Frequent User Username: kevin Post Number: 97 Registered: 7-2009 |
Thanks for the suggestions, sorry for a late response I have been away. However the noise is still there, but not as loud. My mechanic in Brisbane did say it was the speedo cable. So I guess I need to get it replaced or lubricated to see if that helps. I have checked everything else on the vehicle and found nothing else that could possibly cause this annoying flap..I'll let you know when I have achieved my goal in erasing it once and for all. Thanks Kevin |
