Laying down a smoke screen

[Motard]

Laying down a smoke screen, help you guys please!!

Hi Guys,

Lovely morning so I thought I would take out my 250TD, haven't used it for a couple of weeks. Driving down the road and glancing in the mirror I saw I was making lots of smoke, a light, bluish grey.
First thoughts were head gasket but that would have been white. Stopped the car, looked under the bonnet, nothing obvious. Carried on the a friends 3 miles further on and looked again. On revving the engine it would immediately send out a puff of smoke which stopped at high revs.
Set off for home, 10 mins away. Still leaving a trail of smoke and then it suddenly stopped! Couldn't get it to smoke whatever I did!
The car doesn't seem to use oil, I had it changed when I bought it and haven't done enough mileage for another yet.
It is a bit of a worry as tomorrow I was going to use it to collect friends from Toulouse airport and it is a great load carrier, maybe I should leave it in the garage.
Any ideas anyone?

Bob

 

[andy_k]

you have mail

Andy

 

[Dieselman]

Possibly a dribbling injector or some oil lying in the manifold.

Don't worry too much as it has cleared and sounds more like quenched combustion than burning oil.

Drive it and see.

 

[Motard]

I went out again with it, same result. It smells like burning oil Dieselman rather than diesel.
This time I did notice that the smoke changed in colour and became more blue ( just noticeable) the hotter the car became.

Bob

 

[Dieselman]

Blue from what colour, Black, white?

 

[Motard]

Dieselman,

It begins as a light blue grey, quite dense, then I saw it changes to an almost transparent blue after 10 mins. I haven't really done any miles with it yet but I am contemplating doing 150 miles tomorrow.

Bob

 

[Mark300SL]

Check the condition of the air filter - if the engine is "breathing" heavily then it may well have contaminated the filter to the point that the engine is currently ingesting its own oil !

If this is the case - clean all the induction pipework and replace the filter - then find the problem (blocked breather etc )

HTH

Mark

 

[Motard]

Thanks everyone.

I went out in it today....150 miles. It smoked to begin with then stopped, I thought this was something to do with the engine reaching its normal running temperature but it isn't. I stopped for some minutes and the engine maintained its temperature and it smoked again so somehow oil is getting in there. It is definitely oil burning and not diesel. Tomorrow I will change all filters.

Bob

 

[markovich]

i have a 1984 280e mine does the same for about 5 mins after starting its the valve stem seals i was told

 

[Motard]

Took it out this moning and it is much worse, really laying down a fog and p1ssing off other drivers. See what happens with the new filters.

Bob

 

[Dieselman]

I agree with Markovich that it could be the valve seals allowing oil into the engine when switched off and then burning off when under way again. Fialing that the head gasket could be leaking.

 

[Motard]

Thanks Markovich, Dieselman. A MB mechanic reckons valve stem seal also. Sometime soon I will remove the camshaft and take a look. Dont really want to take the head off but it is not an easy fix without special tools apparently, a problem compressing the valves....any ideas.

Bob

 

[Dieselman]

You can buy / rent valve spring compressors that allow you to remove the spring without removing the head.
There are two types. One that bolts to the head and you push down on the valve collett and remove it, the other (and better) is a small special two leg puller that winds down and compresses the spring.
There are compressed air types too but unless you have a compressor forget it.

In both cases make sure the piston for the appropriate cylinder is at TDC, otherwise the valve will drop into the cylinder necesitating head removal.

It sounds like you may have a loose seal which is forcing oil down the valve inistead of stopping it. Once there is oil in the exhaust it will smoke for a while once fixed but will clear.

 

[Mark300SL]

I use a long length of window sash cord on petrol engined cars - tie one end somewhere safe and feed the rest into the combustion chamber until a significant amount is in the bore - now wind the engine up to TDC or until it locks

Now you can compress the spring, remove the collets and replace the stem seals

I have done this at least 20-30 times in the last few years and it save a lot of expense and time

I just dont know if it will work on an MB diesel as I have never worked on a modern one

HTH

Mark

 

[Dieselman]

Cord or string works ok but you cant get it into the combustion chamber on an indirect diesel as the glow plugs and injectors only access the swirl chambers.

 

[Mark300SL]

Exactly what I thought might be the case

Mark

 

[Motard]

Thanks guys for all the help. Dieselman, do you have any idea how/where I can acquire this special two leg puller?

Bob

 

[Dieselman]

Either a hire shop or a "proper" tool store or a specialist trade supplier like Snap On, Britool or Mac tools.

Look in the yellow pages for hand tool stockists or even try a local engine reconditioner, you may be pleasently suprised that they may rent or sell you thir own tool.

 

[Motard]

Hi Dieselman,

In France it is not so easy to find things as it is in UK so I would have to source one there. Problem is I have no idea what to ask for to be sure the thing will work!
I am OK if it concerns wine, cheese, oysters and stuff but valve spring compressors? Difficult! Can anyone put a name to what I need and suggest where to buy it pleeeeeeeeeease?

Bob

 

[andy_k]

http://www.premiertools.co.uk/item8146.htm

something very much like that

Andy