clubstylus

Good evening/morning I went out on sunday to use up the half a tank of fuel in case it went stale!! since last week and whilst flexing the throttle cable to its fullest i experianced a viberation/rumble from around the mid to rear of the car whilst at a higher road speed this went when the throttle was released it does not seem to happen on the legal limits of say the motorway but when higher speeds are experianced (on private roads!) the viberation comes back. I have checked the prop shaft and the uj`s seem ok with no freeplay and are lubricated well too. There is a degree of freeplay in the diff (between flange and road wheels) oil level and colour/smell ok
What sort of allowable freeplay is acceptable and would this freeplay give a viberation/rumble at this type of driving conditions?
Also the smell was a coolant on exhaust smell, this was smelt after the rpm was stretched in 1st/2nd, i have done a pressure check on cooling system and a chemical check for headgasket faults, all ok. Is this normal for 1.8 zetec? (I only work on VAG cars all day )
Phil

Can't imagine what that smell might be , especially after you've tested both relevant things but the vibration may possibly be '' the panhard allowing the prop to be - just touching - the tunnel upright '' (bushes ) OR possibly a weight has dropped off one of the rear wheels
In my case that vibration was the diff nose bearing nut loosening but you've checked that Is your exhaust close enough to something that would only touch at top end rev's Does your pressure cap need changing or need a new rubber ---- smell wise

Hi Phil, Topping up the diff oil helped with a similar vibrating rumble - English axle
Mike

Diff oil sucked out and renewed and no change, the panard rod just kisses the diff when its up on the two poster ramp but when on the floor there is about a 1cm gap which gets bigger with weight in the car, the smell is 100% antifreeze so i`m going to renew the cap. I will have a look again the weekend now its going to rain.

Sorted. The rad cap letting by under pressure and the knock was the exhaust hitting the chassis when under full throttle and knocking itself to death, new cap and exhaust fitted so full throttle again and no more smelly noise