What is my engine burning?

[2s9je0af]

1994 K1500 TBI 5.7 170K miles (mud truck since paint failed ~2001, fuel pump died in 2012 sat under oak tree until 2023)

I have "white smoke" that comes out of exhaust when idling. Doesn't smell sweet like coolant or dissipate quickly like water vapor (hangs around like oil smoke). The smoke burns my eyes. Might have a blueish tinge but not really. If I didn't know better I would say its transmission fluid being burned but I don't know how that would get inside an engine (I have tranny/oil aux cooler). I did grossly overfill the transmission (I needed to move it before I could measure how much to put in). I think the overflow burped onto the headers. I lowered the fluid level and hosed everything off the next day. Smoke is still a thing and definitely seems to be coming from inside exhaust and it only seems to happen at idle. Could I just be burning off the contents of a fouled cat full of "doodies" (truck ran without emissions gear working for unk time)?

So far new Fuel Pump, Injectors, EGR, Vacuum Lines, TBI gaskets, plugs, ICM, coolant, thermostat, CTS, O2 sensor. Ov er past month of tinkering it went from not running to running rough with black clouds (rich) to pretty smooth/healthy sounding.
BLMs seem like they are 116-135 usually ~128. I do see the BLM hit 146 in park (when I notice the smoking)!



I tried attaching my tunerpro log.... only seems to accept contents dumped as a .txt. Paste into excel to understand it...

 

[b454rat]

prolly burning engine oil. If it's not water, then has to be oil. Smoke at idle usually means rings. I had an engine that if idled too long would look like a James Bond smoke screen taking off....

 

[Drunkcanuk]

There was a comment in another thread recently that said something like when the smoke burn your eyes, it's unburned fuel.

 

[2s9je0af]

So I see a vacuum modulator on rockauto listed for the 94' 4L60E... do I have one of those on an electronic tranny? I feel like my truck wasn't smoking before I overfilled the trans. Maybe the trans fluid is going into the intake manifold. Transmission fluid was lower today after driving around block for 20 mins.
.
*PCV looked ok too (its new). Whatever this is it smells to nasty to be oil... I'd think the computer would catch a rich condition if it was fuel... It is more white smoke thank black/blue.

 

[CumminsFever]

You didn't mention if you put fresh gas in it.
Possibly it's the mix of old gas and some oil getting past the rings?

 

[NickTransmissions]

So I see a vacuum modulator on rockauto listed for the 94' 4L60E... do I have one of those on an electronic tranny?

No

I feel like my truck wasn't smoking before I overfilled the trans. Maybe the trans fluid is going into the intake manifold. Transmission fluid was lower today after driving around block for 20 mins.

That's not what's happening. You simply have a trans fluid leak if your fluid level is dropping.

 

[2s9je0af]

You didn't mention if you put fresh gas in it.
Possibly it's the mix of old gas and some oil getting past the rings?

I forgot to mention new fuel tank + delphi pump + fuel filter -> premium gas with a little stable.
Fuel+oil...That's a good a guess as I have right now... Most logical choice

I did just light a piece of toilet paper with transmission fluid... same white smoke but it didn't have the eye burning bad smell.

*to clarify it is not a lot of smoke when the engine is running or consistent. Perhaps I am just seeing a little bit of something coming out the tail pipe but the smoke that is smelly is just from the externally burning trans fluid up front?

I think the next step will be a dry/wet compression test. I wish I knew where the burp area was for the transmission so I could clean better.

 

[2s9je0af]

What about brake fluid? When I press the brake pedal the rpms increase by ~100. I thought I just had a vacuum leak and could replace the booster at a later date. Burning brake fluid would smell pretty bad... This seems like it would make sense.... except the reservoir isn't low and I have working brakes.

 

[tinfoil_hat]

What about brake fluid? When I press the brake pedal the rpms increase by ~100. I thought I just had a vacuum leak and could replace the booster at a later date. Burning brake fluid would smell pretty bad... This seems like it would make sense.... except the reservoir isn't low and I have working brakes.

Pull the vacuum line and see if there is brake fluid in it. I would think the reservoir level would drop pretty fast if this were the case, though.