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Pics of "100% Biodiesel use" by EcoTX on 02 Sep, 2012 10:23
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So I'm tearing down this motor out of a Rabbit I bought for parts.
Guy said he was driving it on 100% Biodiesel and now it has no compression in the cylinders.
I ran compression test and all were under 150 psi, the numbers were worse going through cylinders 1-2-3-4.
Here's some pictures...
Well that's all I got so far...
The valve cover was glued on with RTV. Had to pry it off with a bunch of screwdrivers.
I can still see the VW/Audi logo on the bottom of the head so that means it hasn't been shaved.
THICK NASTY SLUDGE all in the head...
I'm about to go scotch brite some more and pull the pistons to check them and the rings.
There is NO RIDGE on any of the bores, bore 2 is the best looking.
The rest just kind of get rough as you go up into all the polymerized crap I haven't scrubbed off yet.
I tried to get good pics of it all.
I think this thing just got all polymerized, blew the headgasket, coked up rings, etc and just needs to be cleaned out real nice.
One of the bolt holes in the block is stripped too I think but haven't confirmed. I'll get a pic of that later.
I don't see valve damage (which is originally what I thought might be the problem), but will probably take apart and clean the head out real good and check it out as well later.
What's it lookin like to yall? I'll have more pictures later of what I find.
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#1 by CRSMP5 on 02 Sep, 2012 10:41
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got real freeken hot... look at the verticle cylender scoring... the between 2 and 3 on head gasket also looks blown...
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#2 by Gizmoman on 02 Sep, 2012 11:55
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Man that's nasty lookin
I don't know if this engine had oil squirters but if it does, they are probably filled with blue stuff not to mention other small oil passages.
I read somewhere that Bio is "clean"?
Good luck on the rebuild -
#3 by libbydiesel on 02 Sep, 2012 12:41
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I would guess that non-diesel spec oil was used for a very long time resulting in the sludge in the valve cover area and sticking of the rings. With the rings sticking, the compression went in the toilet and deposits formed in the cylinders. I also imagine some over-heating was involved. None of that is was by biodiesel.
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#4 by 8v-of-fury on 02 Sep, 2012 18:28
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I agree that bio diesel did not cause this to happen, how could it? There is no "soot" in bio diesel from what I understand.
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#5 by 745 turbogreasel on 02 Sep, 2012 18:32
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Is that oil in the valley? or axle grease put there in an attempt to hush the valves?
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#6 by burn_your_money on 02 Sep, 2012 21:13
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Was it bio or WVO? A lot of people don't know the difference and use the two interchangeably.
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#7 by EcoTX on 02 Sep, 2012 22:04
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got real freeken hot... look at the verticle cylender scoring... the between 2 and 3 on head gasket also looks blown...
Overheat...possibly, but not severe.
The head is still flat and not even a hairline crack between the valves!QuoteI don't know if this engine had oil squirters but if it does, they are probably filled with blue stuff not to mention other small oil passages.
1989 Hydraulic ME block.QuoteI read somewhere that Bio is "clean"?
None of that is was by biodiesel.
I agree that bio diesel did not cause this to happen, how could it? There is no "soot" in bio diesel from what I understand.
The way I see it is this guy was definitely running some other crap through this thing that was NOT #2 ULSD.
He says "100% Biodiesel", well it's Austin and there are a few biodiesel options so I don't have complete reason to doubt it.
This engine bay reeks of rank vegetable oil.
Perhaps he was running WVO or SVO or crappy made homebrew stuff he was cooking up in his bathtub I don't know...
I think whatever stuff this guy was running was mixing in with his oil big time.
That and/or combustion gasses through a compromised head gasket perhaps.
The oil was so sludged up I got out of it, the bottom layer of crap is like an inch deep and that was just sitting a few minutes. I can't wait to get the pan off and really see more.Is that oil in the valley? or axle grease put there in an attempt to hush the valves?
You know, it definitely has the consistency of grease, it could be grease!
Never heard of that trick...
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I also found a crack in an odd location on the head.
The bores are cleaning up very nicely.
I'm hoping a light ball hone is all they will need to fit standard rings as it sure does look and feel that way.
I can't pull the pan and get the cylinders out until Tuesday since I don't have a 1/4" drive 10mm swivel socket to get those 2 bolts out on the trans side.
When did they go to the trans cover that was removable and gave you more room to get those suckers out? My AVX has a removable bottom plate there to easier access those two PITA's.
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#8 by libbydiesel on 02 Sep, 2012 22:12
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There's no way I'd run that head without at least having it pressure tested.
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#9 by mystery3 on 02 Sep, 2012 22:14
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I may have skipped over this in reading but how many miles on the engine? How long was it sitting? What kind of oil change intervals was the PO running? Looks like it's cleaning up ok. What's up with the vc gaskets made from rtv? I've never had a problem with leaky vc gaskets after I changed to the rubber one.
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#10 by EcoTX on 02 Sep, 2012 22:58
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There's no way I'd run that head without at least having it pressure tested.
Point taken.I may have skipped over this in reading but how many miles on the engine? How long was it sitting? What kind of oil change intervals was the PO running? Looks like it's cleaning up ok. What's up with the vc gaskets made from rtv? I've never had a problem with leaky vc gaskets after I changed to the rubber one.
This is an 89 engine that was thrown in a 82 Rabbit I bought for parts. No clue how long it sat or oil change intervals.
Previous owner say'd like 79,000 or 89,000 for mileage, something under 100k, but don't they all say that...
My 84 Rabbit had a definite ridge you could catch a fingernail on, but it still made 400+ PSI after getting it back together so that gives me high hopes for this block.
Maybe it hasn't been abused too long for everything to get out of tolerance.
I really wish I knew WTF was up with that RTV glued on vc, that was so asinine.
Tomorrow I'll just be checking piston protrusion and maybe dig into the head.
I have a turbo pump I need to get back together as well the next day or two.
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#11 by theman53 on 03 Sep, 2012 05:28
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Those vertical scratches don't come from running really cool. It got hot. FWIW the cracks between valves don't always result from high heat.
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#12 by RustyCaddy on 03 Sep, 2012 07:57
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The oil was so sludged up I got out of it, the bottom layer of crap is like an inch deep and that was just sitting a few minutes. I can't wait to get the pan off and really see more.
Getting a thick sludge of polymerized crud at the bottom of the oil pan when running B100 and especially vegetable oil in a already low compression motor is really common. Neither fuel flashes on the cylinder wall they way diesel does and it gets into the pan. The PO really should have always changed the oil at 3000 miles or less. i wouldn't run veg oil at any mix in a VW motor with compression less than 400 lbs in all 4 cylinders. -
#13 by EcoTX on 03 Sep, 2012 09:31
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Getting a thick sludge of polymerized crud at the bottom of the oil pan when running B100 and especially vegetable oil in a already low compression motor is really common. Neither fuel flashes on the cylinder wall they way diesel does and it gets into the pan. The PO really should have always changed the oil at 3000 miles or less. i wouldn't run veg oil at any mix in a VW motor with compression less than 400 lbs in all 4 cylinders.
Thank you for posting this, it definitely confirms what I'm finding so far.
I wish I knew how many miles the guy got out of this thing before it just gave it up.Was it bio or WVO? A lot of people don't know the difference and use the two interchangeably.
It was definitely biodiesel, he had clear lines running and the fuel was light yellow like vegetable oil.
I dribbled a bit on my fingers from the filter and it definitely had that greasy, vegetable oil smell to it.
Felt a lot more filmy and oily than diesel too. -
#14 by R.O.R-2.0 on 03 Sep, 2012 09:35
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Those vertical scratches don't come from running really cool. It got hot. FWIW the cracks between valves don't always result from high heat.
that looks just like the bores of my Jetta engine, and i heat seized it going up a hill @ 100mph..
temp gauge didnt even budge from half way..