blue smoke

[brendo]

99 2.8l td when idling ever 5 seconds the idle goes down and blows blue smoke then up again and is clear can anyone help thanks

[nissannewby]

blue smoke tends to be a sign of burning oil could be turbo seals, valve stem seals etc.

[perni_a]

or piston rings too :S

[Richo460]

are you getting excessive oil blowing back into your intake throught the egr valve? Strange that it comes and goes. Install an iol pressure guage to get a better idea of what is happening.

[Lieney]

As said. It could be lots of different things.
Valve stem seals, turbo seal (hope its rebuildable), piston rings, etc etc

At idle and once warm, remove the PCV and feel for pressure coming out the outlet. If you can feel air pulsating or pushing it's way out then it could be big problems. Ensure the hose from the PCV through to your inlet is clear from restrictions.(it may have a check-valve so ensure this works)
Escess crank pressure build-up, due to a blocked or restricted PCV can cause seals to fail, including turbo etc etc.:furious:

Once warm, go for a drive and see if it [blows U]more[/U] blue smoke during the following:
1 - under acceleration,
2 - when decellerating in gear,
3 - at idle, and
4 - after decelerating and then sitting idle for a minute or so.

Give us feedback after you've test-run it on where the most smoke is caused.

[Finly Owner]

I usedto drive a UD truck that idled up and down by its' self, but itdidn't puff smoke. And it's still running as strong as ever now with another owner.

I think you are getting a pressure build up in sump which is releing by blowing oil past the rings which is causing the smoke.


Tim

[brendo]

thanks guys and lieney i'll try that and get back in a couple