Mystery of the disappearing rumble/vibration

[MPx]

I went to the Bristol and West Classic show on Sat and tried to take the Esprit. The car hasn't been used for a while (though is has been started and run around the drive a few times in the off season). Anyway did a gentle warm up through the countryside to the A303 (about 10 miles) all tickety boo .... then accelerated onto the dual carriageway. Got to about 70 and there was a horrible deep loud rumble from the front end and the steering wheel shook violently like the wheels were hopelessly out of balance. Slowed and sped up again....same effect. Stopped at the Cartgate picnic spot which was on the next roundabout and looked at the front end - got hold of each front wheel and tried the are the bearings shot test - all seemed just fine. Got back in the car and accelerated back onto the dual carriageway....same rumble and vibration. B****r! Turned the car round at the next available point and drove home at modest pace with no issues. Swapped to the bike to go to the show!

Next day, took the front wheels off. Lots of rusty suspension components to be seen, but nothing that looked or felt like it was broken. Put the wheels back on...went for a test drive...no problem. Thought that was odd, so left it another couple of hours then replicated my trip to the B&W. Got all the way down the A303 to the Shepton turn and all the way home driving whatever speed I wanted - no problem.

So what was the issue on Saturday? I can think of lots of nasty things it could have been, but none that would get better on their own overnight. Normally I'd just accept my good luck and keep shtum, but I'll be at Castle Combe as usual in another couple of weeks and I dont want to waste the trip and track time if the car is suddenly going to misbehave. Any ideas???

[Dave Freeman]

Just a thought but I had exactly the same problem a few months ago, bad vibration at any speed over 60 mph, not all the time though.

I found that the bonnet release was not locked, locked it and the vibration disappeared.

Worth a try.

Dave

[iainskea]

Hi Mike,

It could be just wheel rubber out-of-round that is the problem (given you said you were off the road for a bit). If it happens again, swap the spare on and see if the vibration goes away.

Otherwise, I would say a bearing. Pop the wheels off and check the nut is tight and secure first before a new set of bearings if need be.

Also, to make sure the vibration is coming from the front and not the transmission, clutch the engine when the vibration is in play - that will rule out the engine etc.

Iain

[Paul C]

Flat spots on tyres?

If it's sat for a while without being used then the tyres could have flat spots where it has been resting.

Would explain why the rumble vanished too, once they have got warm and become round again...

?

...Err like he said above while i typed!

[MPx]

Thanks guys - some good ideas.

It wasn't the bonnet catch cos that was definitely closed/locked.

I dont think it was a bearing cos I dont think that would have got better with more use - but I may just check the nut before Combe as a precaution.

Outside chance it was Clutch/transmission judder - less likely but could say have been working towards a siezure and the smegma build up unbalanced the flywheel til they were polished off through use.

But totally believable explanation:

Flatted tyres - its been stood a while and I guess they would true up again after a heat cycle and some use. I'm going with that- its fixed and requires no more angst or costs.

Ta muchly!

[matk]

THe only thing I can think of are loose wheel bolts, but you would have picked up on that when you took the fronts off. I would however check the rears too. I've heard of some rear suspension issues manifesting as symptoms at the front.

[Jimjitsu]

steering rack, underinflated tyres,front tyres would also cause the esprit to feel very misguided at speed. wheel bearing gotta be something like one of them

[trackmagic]

I had a similar situation and it turned out to be worn trunnion bushings. Really shook under braking.

happy hunting,

jeff

[MPx]

Some more good thoughts here.....if I still had a problem, but as far as I know the car is now fine. Most of these issues wouldn't have miraculously got better on their own over night which is what apears to have happened to me.

[Dave Freeman]

Glad its ok, just keep an eye on it.

Keep us posted.

Dave

[molemot]

An Esprit that mends ITSELF??!! I want one of those!!!!!