E30 Zone

When i start up the car there is an embarrassing cloud of blue smoke but then it goes away after a few revs and never comes back even at high revs. there is a strong smell of petrol in the exhaust fumes too.

what does this mean?

Valve stem seals?

maxfield wrote:Valve stem seals?

Would be my guess too. Wouldn't be the cause of the petrol smell though. Does it burn oil?

sounds about right!

Blue= oil
Black= fuel
White= condensation

thanks,

valve stem seals ? bollox, sounds expensive.

what if the cloud of smoke is white and it's condensation? what is the problem there?

The seals themselves are pretty cheap, its the fact its a head removal and strip down job that'll make it expensive.

If the white smoke only appears when the engine is cold, its probably due to the cold engine and exhaust.
If its billowing white smoke when its warmed up, your looking at coolant in the exhaust / combustion chambers which is probably the head gasket.

valve stem seals should still smoke blue slightly when you give it beans and then let off shouldn't they?

other option is it might be slightly worn piston rings, when they heat up slightly they expand, and then don't leak the oil anymore....just a suggestion

If it was piston rings it would give out blue smoke all the time when engine is on...

They expand but also the block expands...

also oil gets warmer and thinner..

valve stem seals will show themselves at higher revs also

they could be getting tired allowing oil to leak down whilst the car is sat..

maxfield wrote:If it was piston rings it would give out blue smoke all the time when engine is on...

They expand but also the block expands...

but the piston rings are deliberately softer metal, as so not to wear the block, which also means that they will expand more than the block...


and sorry, i'm not trying to convince its piston rings....its just an input

same with my new car
i think mines stem seals too.
oil leaks down while car is sat
start up to a puff of lovely blue "engine death smoke"

My car always stinks of petrol when you start it up, big smell of emissions although it passed MOT with flying colours. No blue smoke but there seems to be oil weeping from the engine when left sitting, sounds like stem seals?


cheers

Valve stem seals link into the bores... Not outside the engine.

M20's without oil leaks are rare!

I hear that you can change the valve stem seals without taking off the head if you knock the center out of an old spark plug and tap it to take an air line
If you then put it in the clinder you are working on and build up the pressure that it will be enough to hold the valve up when compressing the spring
I have not done this my self but a local mecanic sweares he has
My seal,s are gone and i might give it a try for the laugh

yeah if heard of that way of doin it..... never tryed it.
anyway
"i love the smell of burt oil and hydrocarbons in the morning"...........
it just wouldnt feel like my jorney to work if it diddnt begin with the trail of blue smoke up my road. my valve stem seals are fine just as they are...... hard, brittle and fooked!

Yeah

Ive the same problem on my car.

Been to the engineer who said that Blue smoke on startup and when shes driven hard is most likely a sign of valve stem seals. The reason for the cloud of smoke in the morning is that during the night ( with worn seals ) the oil seeps through and collects and in the morning on startup that oil gets "burnt" off hence the cloud of smoke.
Quotes range from £275 - £350 plus vat and thats with me removing the head myself.

Also beware as when the heads removed you need to check for corrosion on the head from the coolant as the coolant should be changed every year and a half or two as prolonged use of coolant (unchanged) causes excessive corossion on the head and surroundings etc. Im told the coolant becomes sort of acidic.

Just weighing up the options at the moment.

Might be an exciting learning experience though to replace the seals and remove and replace the head, not to mention the cost savings.

Cheers

if you wanted to do it yourself, its not that hard at all