7.3 PSD, WVO on Greasecar conversion: black goop from exhaust
 

Hey folks,

I've put a few hundred miles on my greasecar conversion, running oil that has been filtered via 5 micron bag filters.

I'm noticing a lot of grey smoke when running on WVO, and I'm getting a lot of crud and some black oily substance out the tailpipe. Does not appear to be engine oil since the engine oil level is remaining steady. When I switch back to diesel fuel I get a lot less smoke (almost none at idle, and while it does smoke black on uphill grades, the smoke is a lot less thick than it is when running on WVO). I was not getting crud from the tailpipe on diesel fuel.

Power seems about the same as on diesel fuel. If I climb a grade and turn off overdrive, and push the boost to at least 12 psi, I get less smoke, but it smokes even on level ground with minimal throttle (and especially when idling at a traffic light).

I was wondering whether this is normal. I've configured the Greasecar system to cut over from diesel to WVO once the coolant temperature reaches 180 degrees, so I'm always getting hot WVO at the injectors.

My biggest concern is the tailpipe goop, not the smoking, but I imagine the issues must be related.

I've confirmed that if I do ~50 miles on pump diesel, the goop dries up and the smoke clears up. The dried goop looks like carbon buildup. I'm wondering whether maybe my WVO has water content, or something. I need to test.

What year psd? The black goop could be consistant with whats been built up in the exhaust over the years. The spent wvo is really abrasive let alone a cleaner. Could be doing just that, cleaning the exhaust....i ran 100% wvo for 4yrs/150k...:-X22

It's a 97 PSD. Could very well be a lot of accumulated crud, as the truck is approaching 400k miles. I've got a 203-degree thermostat and a flat plate heat exchanger on order, and will see if I can push the oil temperature as high as possible before it burns and get better results. Will report back.

Well, the higher-temperature thermostat and FPHE did not clear up the smoking issue.

What finally seemed to fix things was replacing the IPR. The truck got harder and harder to start and finally quit starting at all. When I could get it to start, I had to stay on the throttle or it would immediately die. Replaced the ICP and EOT sensor to no effect. Replacing the IPR cleared up all the symptoms and resulted in a noticeable power increase.

And the black goop from the exhaust is gone. Definitely worth the $170 for the IPR. It's a lot of work to get to it, especially with all the extra plumbing for the veggie oil conversion.