Engine/Transmission (1994 - 1998) White smoke at high RPM

[alaskagrizz]

I have a general question about what condition actually causes white smoke at high RPM, especially when shifting a manual transmission at governed RPM? I am now on my third 12V since buying a new 93 10 years ago, and I have never really noticed this before. My current truck is a 98. 4 12V 5 speed 3500 I got one year ago with 22K virginal miles. I have yet to get serious about bombing, as I plan to replace the main limiting factor this winter... ... . the clutch. After that, Katy bar the door! Anyway, I have only recently noticed a considerable puff of white smoke when taking a shift to the stock governor springs. It seems most noticable at night, with headlights illuminating my tail. I am a 25 year Aircraft Mechanic, yet I am scratching my head at exactly what condition causes this? I have yet to advance the timing on my 215HP CPL 2175, and I know this helps many things... ... including white smoke reduction. Just looking for those "more in the know" to shed a little light on this. Thanks for all who contribute to the wealth of information we all have here in TDR, what a resource!

 

[Snow man]

Id go ahead and advance the timing,it sounds like its a tad on the late side now.

 

[illflem]

The timing is almost always off from the factory. Suggest any truck that hasn't been timed get it done even if you want to keep the stock setting.

 

[JohnE]

If both your first and second trucks were 93 or earlier it explains things. The VE pump has built in timing advance. The PE, while a much better pump for fuel delivery, does not have any (injection) timing advance capacity. Any late timing from the factory is really noticeable, especially as your post subject states "White smoke at high RPM".



Get the timing advanced to around 16°. You will really like the results, except for very low rpm performance, but with a manual I don't think you will notice.



-John

 

[DavidGardner]

alaskagrizz



I know this sounds over simplified but have you replaced your fuel filter? Friend of mine had a 96 12 valve that was doing the same thing. Changed the fuel filter and problem solved. Also the truck would run rough when he got on it and at the same time the white smoke would appear from the tail pipe.

Just a suggestion. Some times the simple things work.

Good luck and let us know what you find.

Dave G.

 

[The patriot]

The way youre seeing it at night with lights behind you, you'd see smoke even if it wasnt smoking at all.

Having said that... I see the same thing with mine at night.

I still have the factory timing. I'm sure bumping it up a bit wouldnt hurt as they're almost always set are a bit on the conservative side.

Eric

 

[alaskagrizz]

Just an update......

Thanks to all who contributed to my post. I did in fact recently changed the fuel filter, and clean the screen in the fuel heater..... about a month prior to posing this question. I have since noticed the smoke during the day too, coming on about 2600RPM... ... when my right foot gets too heavy! Anyway, it seems to run smooth from idle to governor set point..... just never saw the smoke before. I am going to run the timing up too 15. 5 or 16 in the next month or so, hopefully that will make my beloved 12V happier!