Heavy vibration at speed

[wadgebeast]

Just bought a Mondeo as a throwaway £250 banger to keep my MG B off the road except for when I want to take it out.

However, just managed to get the Mundane up on the dual carriageway and it vibrates heavily at motorway speed. It doesn't make any difference if the wheel is dead ahead or slightly angled, so I suspect it's not the power steering (although I'll check the levels later). The odd thing is that it comes in phases and then disappears - you get about 20 seconds of vibration and then it disappears again.

The tyres are cheap and nasty, but don't look blistered. It runs fine below 60mph.

Any other ideas? Bushes? I can't hear any rumbling that would suggest a bearing and the wheels don't feel loose when I waggle them by hand.

[leorest]

Could it be two different vibrations coming into and out of phase? One minute they cancel each other out and the next they add together.

I've put best part of 100k on a Mundano and not come across this.

[annodomini2]

Get it down the garage or up on axles and check all the bushes an wheel bearings, if you find nothing get the wheel balance checked.

May also be wise to check for bent bodywork and get the tracking checked.

Actually you may be better going straight for the tracking check as most don't charge (to get you in for the business) and let them find it!

Don't let them fix it and change the bits you need.

[GreenV8S]

I've had simmilar symptoms with wheel shake happening sometimes and then going away for a while, and my guess was that it was caused by both front wheels being slightly out of balance and coming in and out of phase with each other. But I've never had it come and go as quickly as 20 seconds, that would imply a significant difference in rolling circumference between the front wheels which is a bit alarming.

[wadgebeast]

annodomini2 said:

Get it down the garage or up on axles and check all the bushes an wheel bearings, if you find nothing get the wheel balance checked.

May also be wise to check for bent bodywork and get the tracking checked.

Actually you may be better going straight for the tracking check as most don't charge (to get you in for the business) and let them find it!

Don't let them fix it and change the bits you need.

Cheers - that's not a bad idea! I didn't think it was the wheel balance as I'd feel it at lower speeds.

[tribbles]

I possibly had something similar on my Mondeo as well - although it was more of a buzz than a vibration, and it could be felt very strongly from the floor. It didn't seem speed related; I didn't think that a wheel bearing would have been felt so hard on the floor. I was worried that I wouldn't make my destination (it was also overheating), but it managed it there and back.

Anyway, the exhaust was blowing a bit so I replaced that and it hasn't done it since, so it could've been the exhaust rattling on the chassis somewhere...

And the overheating was a thermostat not opening fully (but enough for the radiator pipes to get hot). It's now back to its usual self.

[wadgebeast]

It's bizarre, but it's actually getting better every day. Not the exhaust, because it's just been changed. Taking into garage on Friday pm to have tracking checked and I'll have a squiz at the bushes while it's on the ramps and I can see.

[Matthew C]

I recommend getting the wheels rebalanced before looking too hard for problems.

[steve_d]

Matthew C said:

I recommend getting the wheels rebalanced before looking too hard for problems.

I'll second that. Front wheels you will feel through the steering but rear out of balance comes right through the body.

The guys will also inspect the tyres as they balance them and will soon tell you if something is wrong as they are trying to make a sale. Just make sure you are convinced by the pitch.

Steve