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Kevin Lagden
Experienced User
Username: kevin

Post Number: 39
Registered: 7-2009
Posted on Monday, 18 July, 2011 - 17:51:   Edit PostDelete PostView Post/Check IP

OK, I give up, I have lived with it long enough but each time I take out SRH 19305 on a run I get what can only be described as a slight thumping noise, which I think is coming from the left side (passenger side)I notice it when cruising and when slowing down the noise reduces to the same pace of the car. Don't think its a flat spot on the tyres, as these were checked, they were also balanced etc about 6 months ago. Engine sounds fine, no strange noises coming from anything under the bonnet, apart from a little whine from I believe a bearing in the water pump.

Whilst Im here, is it normal for the engine to tick when warming up and then slowly calm down to next to nothing.

Im also getting an annoying ticking that seems to be coming from under the dash, I need the speedo serviced as it now starts to hop up and down, even bounce after a while, so maybe something to do with that.

Glad I got that off my chest, perhaps somebody out there with far more technical knowledge than I can assist.

Thanks

Kevin
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Jan Forrest
Prolific User
Username: got_one

Post Number: 212
Registered: 1-2008
Posted on Monday, 18 July, 2011 - 19:38:   Edit PostDelete PostView Post/Check IP

The 'thump' from the front wheel could be a lot of things including a worn wheel bearing, an ungreased track rod end or one of the calipers 'chattering' due to loose mounting bolts, although a flat spot on the tread or a bulge in the tyre sidewall is more likely. It would be easy to miss if the bulge was on the inside of the tyre.

Ticking isn't unusual on older V8's (yours is about 4,000 units older than mine) and is almost certainly one or more of the hydraulic tappet followers complaining about a lack of lubrication for the first minute or so after a cold start. As they become filled with engine oil they should subside to an inaudible 'rustle' masked by characteristic the big V8 rumble.

Ticking behind the dash along with a speedo needle jumping around can usually be traced to a fault in the drive cable rather than the speedo head itself. If the inner has worn or the outer has become kinked it would exhibit exactly these symptoms. Just because the sound comes from behind the dash it doesn't automatically follow that the damage is to be found here as sound can travel along the cable all the way from the gearbox end - or anywhere inbetween - to issue forth from this area.
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Nigel Johnson
Experienced User
Username: nigel_johnson

Post Number: 49
Registered: 12-2008
Posted on Monday, 18 July, 2011 - 21:03:   Edit PostDelete PostView Post/Check IP

Hi Kevin, the thumping could be the brakes sticking on and then releasing.Geoff's Corniche used to make that noise until we overhauled the brakes. She wore the front pads out in less than a thousand miles.
Regards, Nigel.
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Nigel Johnson
Experienced User
Username: nigel_johnson

Post Number: 50
Registered: 12-2008
Posted on Monday, 18 July, 2011 - 21:08:   Edit PostDelete PostView Post/Check IP

And sort that waterpump soon!
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Bill Payne
Frequent User
Username: wimpy

Post Number: 64
Registered: 1-2007
Posted on Tuesday, 19 July, 2011 - 04:14:   Edit PostDelete PostView Post/Check IP

Graphite based oil or lithium grease should correct the speedo cable problem. Disconnect from the tranny, cable should pull out without difficulty. Once out, don a disposable glove, put a quantity in the glove and draw the cable thru, efficiently coating the cable. Re-insert, re-connect to the tranny and the cable problem should disappear.
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Jan Forrest
Prolific User
Username: got_one

Post Number: 213
Registered: 1-2008
Posted on Tuesday, 19 July, 2011 - 19:38:   Edit PostDelete PostView Post/Check IP

I'd be more inclined to use a dry graphite lubricant as I've know oil and grease to migrate into the speedo head works and gum them up.