Jump to content

Blue Smoke - '96 300 Tdi


jdk01

Recommended Posts

Hi, blue smoke is pouring out of my exhaust for about 1-2 minutes when I start the engine from cold. During this time, the engine is not responsive to the accelerator being pressed. The vehicle also seems to rock from side to side. A couple of minutes later, the smoke disappears and normal power resumes and rocking stops. Any advice appreciated! Thank you. Julian

Link to comment
Share on other sites

check throttle cable is corectly adjusted at the injection pump, there shouldn't be any big amount of slack in the cable, the knurled handnut does slacken off, a short burst of smoke at start up is normal for any 200 or 300tdi engine, maybe your idle speed is to low -- should be 750 to 850rpm, or glowplugs are not all functioning.

Link to comment
Share on other sites

Defo check the glow plugs, if they're not working the diesel doesnt combust properly and you get white/blue smoke but it seems odd it would do it for such a long time, you'd expect the cylinders to come online within a few seconds if the engines actually running. Maybe a bad injector causing a poor spray which is much harder to ignite?

Link to comment
Share on other sites

Check the cold start mechanism on the injector pump is working correctly: http://forums.lr4x4.com/index.php?showtopic=63051

Otherwise, I've had similar with an old perkins with very worn bores. It used to pump out white and blue smoke until you got a bit of heat into the rings, they expanded, closed the ring gaps, and the compression came up to something sensible. Was very unresponsive until warm. Take the oil filler cap off just after you start it from cold: If you get a big blast of air coming out, you've probably got the same problem.

Link to comment
Share on other sites

  • 1 month later...

Hi,

The blue smoke got worse, enveloping the car during start up. This improved over time as the engine warmed, but the smell of oil/diesel remained.

The main dealer recommended and fitted a new turbo charger and then new injectors. But the smoke persisted.

So, I took it to a small local garage for diagnosis, rather than part replacement. They listened and then adjusted the timing belt, (which had also been replaced by the main dealer).

The result is that the smoke seems to have reduced substantially, except for a little amount when the engine is started....

Link to comment
Share on other sites

Blue smoke is burning oil, Black is too much fuel or too little air, whitish is too much air or too little fuel, so oil is getting into the combustion chamber somehow is my theory...my 300 has no glows wired, a puff of light blue followed by a small amount of black smoke when accelerating for the first 30 seconds.....not clouds of blue smoke, quite what the suggestion regarding throttle cable relates to is beyond me.......

So either worn bores, worn valve stem seals or worn oil seals in the turbo, or an intercooler with oil in it would be my guess......

Link to comment
Share on other sites

Thank you.

The engine does not use any oil.

After fixing the timing, the amount of blue smoke at start up is small compared to what it was and I can now accelerate rather then needing to wait 30-60 secs. The blue smoke has all but stopped after the first few minutes.

I will follow through on your suggestions.

Link to comment
Share on other sites

Reading this with interest and some confusion. Is it blue smoke or black?

I ask because I too thought that blue is oil and black is diesel and considering that the adjusted timing would affect combustion then have you reduced black smoke??

I have a puff of black on startup but sometimes a trail of blue for 300m after first start. I'm planning on changing the valve stem seals with the head on, just as a starter. ( using a homebrew tool shown on this forum).

Link to comment
Share on other sites

Blue after start up is often valve guides actually, and not rings, as they leak oil down into the exhaust port which then burns off slowly as the EGTs rise.

For a turbocharged car, the same is true for the turbo seals, if they lek go you can get all manner of horrid smoke out the back :)

Link to comment
Share on other sites

I would suspect the valve seals and/or turbo too before anything else. I would have thought that if the pistons/bores were worn the problem wouldn't go away?

Can you make it smoke by just revving it on the drive? If so, take off one of the pipes between the turbo and inlet manifold and see if the smoke goes away. If not then I would consider taking the head off to change the valve stem seals.

Link to comment
Share on other sites

Sounds as though the OP is happy with the reduced smoke following the timing adjustment.

I hope you are right Vulcan as I've made the head-on valve compression tool and probably doing my stem seals tomorrow.

Link to comment
Share on other sites

Thank you to for continuing the conversation.

Yes, the smoke is blue and I am currently happy with the reduced smoke following the timing adjustment.

I will ask the garage to check the valve stem seals and valve guides and advise in a few weeks.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy