Valve seals ?

[M3Tony]

I'm told by garage that dust that acumulates on rear end is worn Valve Seals, and that I should live with the mess, or get them fixed. Basically a fine film of dust appears, even on short journeys, though she doesn't smoke, rather on start-up, or 'burst' - like a puff on acceleration.

What is entailed with valve seals - half a day effort, and not much risk ?

Thanks.

[smithy318i]

dont you need to remove the head to replace the seals?
or use compressed air in the spark plug socket to force the valves into thier seats?

I managed to replace the oil seals on an old nissan sunny by rotating each piston to the top so that the valve didnt fall into the cylinder.

[Demlotcrew]

I bet its a leaky rack or gearbox.

Andrew

[johnl320]

On some cars I've worked on I've taken the spark plug out and fed a lenth of nylon rope into the hole. Then turned the engine over so that the piston compresses the rope and holds the vales shut. Once the engine is locked in that position the valve springs can be compressed etc.

HTH

john

[Laurence]

I bet its a leaky rack or gearbox.

Andrew

I know this is a bit of a thread bump but why would this indicate to a leaky rack/gearbox? I have similar symptoms and diagnosing it is proving tricky...

[Laurence]

Anyone????

[Mikey_Boy]

I wouldn't jump to conclusions! Have you checked your oil level over a period of time? Oil or oily dust on the rear of the car could be anything - gearbox, steer rack, diff, etc. Have a good look under the car to see if there are obvious leaks. If there are none and you re convinced its engine, check your oil over period of a week or so. If it goes down dramatically, then check obvious things like crank and cam seals for leaks. Oil consumption can also be caused by blocked or restricted breather pipes so ensure these are checked as well.

Changing to a thicker grade oil may also help - going from 5W40 to 15W50 in my M20 make a big difference.

Try the simple things before taking things apart!
Hope that helps,
Cheers,

Mike

[daimlerman]

I bet its a leaky rack or gearbox.

Andrew

I know this is a bit of a thread bump but why would this indicate to a leaky rack/gearbox? I have similar symptoms and diagnosing it is proving tricky...

Elderly thread alert!

At least the search function is proved to work and has been used.

Principle here is that oil leaks are blown backwards as the car goes forward,so an oil leak from the rack will spread it's self over the underside of the car and end up on the rear panel.

I had a diff oil seal fail(in France,on holiday )last summer,the spare wheel well and the rear panel both got a good coating.

[Laurence]

ah right i understand. Think ill just carry on replacing everything untill it stops lol