Haze or no haze discussion

[jetfiremuck]

Understanding that its an 80s engine in the family of Mercedes early 1.6 vw etc what is an acceptable smoke haze ad idle after a run up to temperature.

In my case I see a slight gray haze at idle not a cloud but a slight haze. Timing is correct and has had new nozzles fitted.

Does any member have a haze free Volvo. I know that haze is in the eye of the beholder.

[v8volvo]

Perfect clear exhaust is not really ever seen with these engines. If you're looking for a little haze you'll always be able to see it, at least that has been the case with all the ones I have ever experienced. Kind of the nature of the beast. These engines were at the cutting edge for technology in their time, but compared to today's engines, they use very low injection pressures and an antiquated combustion chamber design, and of course no electronic timing control, pilot injection, etc. And, no exhaust aftertreatment at all -- not even a simple diesel oxidation catalyst, although it would be easy to add one of those if desired.

It sounds like you have quite a few other diesels to compare it to, so maybe that's the best reference. When the D24/T is running right I think it is better than any old Mercedes diesel is capable of being (IMO those are the worst of all), and about the same as an early type VW TDI.

D24/T is pretty similar for example to the 96-03 1Z, AHU, ALH TDI engines. The 2004-onward PD TDI engines are definitely cleaner, and the 2007-newer ones with DPFs of course are a whole different ball game. But if I stand at the rear of my idling Volvo, or behind my idling 1996 Passat TDI or the '01 Jetta I used to have, or for that matter my 2000 5.9L Cummins, there is not really any difference. All give a little bit of haze and smell. In fact my '96 1Z TDI is probably the worst stinker I have, the Volvos are better than it.

I see you have a handful of TDI cars. Is your D24T Disco much different from them in terms of smoke level?

Alternative fuels (like biodiesel or HVO / renewable diesel) are one way to cut down on exhaust irritations, or at least make the smell less offensive.