[kiamaian]

My Saab 9000 CS with 146000 kilometers on the clock emits quite a large cloud of blue smoke on the first start each morning. After that the exhaust is clear.

I have been advised that the problem could be that overnight oil is leaking past the valve guides into the cylinders.

Not knowing Saab's very well, I don't know if the engines are prone to worn valves and guides, or whether new seals alone might fix the problem.

Has any member replaced the valve guide seals without removing the head?

 

[mikeloadsasaabs]

Is it a turbo?

 

[Mark in Ireland]

At that low mileage it will not likely to be the valve seals, they rarely fail and if they do you will get blue smoke on the overrun.
If its a turbo model the seals on the turbo will be high on my list of potential causes. Take the intake pipe off the turbo and check for oil. 5 minute job

 

[MikeH]

I agree with Mark,the oil seals only show on the overun and even then they will not be worn just very hard.
It is not possible to renew the valve seals without removing the head as you will need to remove the valve springs.
mike

 

[badman]

Mine started off just puffing a bit of blue on start up, then clearing as the engine warmed up.

Gradually, day by day, the smoke got thicker and thicker and lasted for longer and longer......Shot turbo

A trip to the scrappy and a few hours knuckle-skinning and she ran clear again!

 

[kiamaian]

Thanks for the responses.

My car has not got a turbo so that is eliminated as a cause.

Glad to hear the cars don't generally suffer from premature valve guide wear.


Any other suggestions?

 

[StephenA]

My old 2.3 non turbo did that if you started the car with your foot on the accelerator.. that was at 116,000 miles.


Steve

 

[MikeH]

It might be worth checking that all the vacuum lines are clear,in particular the smaller arm of the Y junction into the cam cover,I have seen those choked with carbon and if the breather system is not working then you MIGHT just get some smoke.
I would imagine with your high tempratures it would not be too hard to cook the stem seals,so don't rule them out yet.
mike

 

[mark e]

Are you sure it's definitely blue and not a little black, indicating unburnt fuel on start up?

 

[kiamaian]

I sure am getting plenty of help which I appreciate.

The cloud of smoke is definitely not black and is actually quite white. I probably have been pressing on the accellerator when starting and I will avoid doing that next time to see if that helps. I will also check the vacuum lines.

The funny thing is that I don't always get a cloud of smoke when starting but when I do heads turn to have a look so it is really noticeable.

 

[Aerohead]

Is there a chance you are burning coolant from a blown head gasket?

Might be good to check compression, if bad then the head has to come off for a new gasket ans/or valve repairs.

Good luck!

 

[1989agoodvintage]

White smoke is more likely to be due to coolant in the cylinders. Is it a little lumpy or hesitant on cold starting?

Does seem most likely to be head gasket, or if you're unlucky like I was, a cracked cylinder head. But that was my fault for running it for too long with coolant loss problems.

 

[kiamaian]

Hey guys you are starting to frighten me!

I have had a full compression test done recently and fortunately that was completely satisfactory. Nor am I losing any coolant so hopefully there is nothing wrong with the head or head gasket. After having to replace the electric fuel pump and engine sump I don't want to have to do any more major repairs for at least five years.

 

[MikeH]

Sorry but a compression test will only show in the later stages of a blown gasket,yours could be seeping when the motor is cold and it takes only a little coolant to make a largish cloud of steam.
There is a test to check for exhaust gases in the coolant,try your local garage.
mike