What to use to clean up congealed WVO
 

I'm working on my new to me w210 and the PO ran grease through it. After taking off the cover over the injectors I see that injector 5 and 6 are basically drowned in solidified grease. I sprayed engine degreaser and let it sit, but it doesn't look like it's working it any looser. What would work better to melt that stuff so I can suck it out; kerosene, Bio-diesel?
I'm hoping it just leaked from the braided hoses and I don't have a larger problem with the injectors themselves.
Thanks
Samson

Samson,
Bio diesel should do the trick. Then run it on proper diesel for a while.

Biodiesel will work great, just don't let it contact rubber parts for very long unless the rubber parts are known to be resistant to BD (for example Viton). Do the job when the car has been recently driven -- the warmth will help. Lots of other solvents will work but biodiesel is probably the least toxic to humans and pets while still being a good solvent.

Biodiesel will attack the braided rubber return hoses but it's probably time to replace them anyway. If you plan to use biodiesel in the car even occasionally you should use Viton return hoses. You can get them from fryerpower.com.

Jeremy

So if I pour some BioDiesel down around the injectors and let it sit it will eat that stuff up? Then I'm just looking at replacing the braided fuel lines around the injector too cause it will probably eat through those too?

Warm motor , good soaking, maybe a old tooth brush to help it. Wash it away with water when it has softened the gunk. Probably the inside of the motor is like that as well !!

That's what I'm afraid of, If it wasn't so cold here I'd run a couple tanks of B100 through it, it smokes a bit at idle and I'm thinking the injectors are full of that crap. If a diesel purge doesn't do it, I may be sending the injectors out for an overhaul. But I want to get all the pig lard out before I pull the injectors.

Fair enough, even B50 would help. If its been running on fat, I would have thought that Bio would be much thinner. You will find all sorts of C##P in the fuel system. Best you get a few sets of filters.
Is it breathing bad?

That poor engine.

Biodiesel brakes stuff down slowly. So it may take several soakings to get it off. If you want a quicker action you might try Goof-Off, thats stuff works in a hurry.

DO NOT pour bio diesel down those holes unless you are planing on removing all the fuel lines and injectors and then the valve cover. The BD will eat the rubber gaskets that seal the holes in the valve cover around the injector holes.

What problem is the VO polymer causing? It is no longer vegetable oil or grease. It is now a plastic. Dig it out enough to replace the return lines and leave the rest alone.

harbor freight has a steam generator for cleaning stuff like this...

how does the engine run? definitely replace those formerly leaking return lines, although the VO polymer probably sealed them up by now.

I 2nd this comment above, easiest way to remove it will probably be to scrape it out of there with a pick or small screw driver. I did this on a ford IDI with leaking return lines once, the VO had filled the V between the heads with tons of the polymer residue. That stuff is tenacious, I ended up just scraping out most of what I could get with a putty knife, and leaving the rest.

Removed as a solid substance like that, its not horribly difficult to deal with.

Bio will eventually eat through the rubber. It will take quite some time for that to happen. A one time or two time soak isn't going to melt all the rubber.

Kerosene. I use it to cut wvo when I put it in my 6.2 Suburban when it gets below freezing. WVO is like a sugar glazing once it sets up. Straight kerosene will run in your engine, too. I'd use kero.

Wow, what a mess. Must be from the WVO seeping from damaged return lines for a long time. The polymerization occurs when it is contact with oxygen and is accelerated on metal contact. If you are lucky, the engine was not damaged, as that is a much different environment from just having the stuff accumulating and sitting like that. But if it was running on cold WVO, all bets are off. Am I correct that the entire injector cavity is full of the stuff?

Getting it off will likely require poking and digging, then diligent brushing with a fine wire brush in addition to the aforementioned solvents. Just get new hose and do what it takes to get it clean then replace the hoses. When you get it clean enough I would at least remove the injectors and get them inspected and cleaned, if not just put in new ones.

Edit: yes I looked more closely....drowned in poly....what a mess.