Well, the results are sobering.

compression as follows in psi:
220 240 190 240 250

And take a look at this coke buildup on the crush washer and injector of piston three (the one with low compression). Perhaps this crud broke off and scored the walls/rings? Part of me was hoping the damn thing'd fire up once I unblocked the crush washers...

The engine was definitely worn before I ever got it running on wvo (previous compression numbers are pre-conversion), and it had some repeated trouble starting this winter, even with the block heater. Alas, it appears I'm just another ignorant human mistreating a machine.

Yikes! With those compression numbers you're going to have hard starting. Typically once you drop below 200 PSI the engine will have difficulty even maintaining idle if you can get it started.

It's unlikely that a chunk of carbon fell into the cylinder, the injectors shoot into a prechamber, so there's no direct connection to the cylinder from the injector area. If the carbon chunk fell off, it fell in the prechamber and burned.

The injector tip you show is pretty knackered. If the rest are like that, I'm surprised the engine even ran! Surely it was nailing and smoking?

Might be looking for a healthier used engine if you intend to keep the car going.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

My old Chiltons says you need 220 psi cold for reliable cold starting.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

For the low cost it may be reasonable to try a cylinder soak. There is also a section of the site that deals with alternative fuels. You may find the best method to attempt this there.

It has been done many times by members posting on this section of the site. The soaking takes time and the block heater should preferably be left on. Soak for about a week and redo a compression check. You of course will have to make up whatever solvent is going past the rings. During the soaking interval.

Miracle mystery oil is one that has been used. Personally I would try to find something more aggressive. Just not sure of exactly what. That is the reason I suggested the alternative fuel posts. What seems to occur is portions of the unburnt wvo get into the ring grooves. Logically mostly in the compression ring lands.

It turns into a sticky fairly strong glue initially I suspect. Then perhaps into carbon. There have even been a few reports that engines that have used wvo on occasion have vertical scoring marks on the liners. I have had some issues with exactly why that occurred.

I have limited abilities. During the wvo craze. I thought a lot of people got aboard. When they did not even have the skill level to deal with problems that develop on engines and systems just using diesel oil.

What a person does with their car is their business. I was just a little sad that their outcome was not really being considered by many of them using it. I understood at the same time the siren call of free fuel was very strong for them.

My approach was somewhat unique instead. I got diesel fuel really cheap during the peak of the craze. That is never going to come my way again. At the present time I pay a little more than 4.00 American for an American gallon of diesel up here in eastern Canada. Basically being about 1.30 Canadian for one liter.

At the same time I thought some might do okay with wvo. By being really thorough. Unlike diesel oil if any air can get to Wvo. A chemical process starts that is going to thicken it and eventually solidify it. So a car using wvo should almost be in constant daily use.

If you are able to restore compression to a reasonable level by soaking. The injection pump and injectors should see a similar cleaning effort. Acetone or laquer thinner are good chemicals for that. Forget using things like diesel purge.

Anyways if you do decide to try and manage to get usable compression back. Post that you did. So options of what to use and how to do it can be obtained from site members. To clean out the injectors and injection pump.

So now it is just a play thing to experiment with.
First, try water injection. I have had success freeing up stuck rings.


Simplest way is to have one person operate the throttle while the other sprays water from a sprayer bottle into the intake. (Don't do it this way with a turbo engine, the water droplets can pit the turbo blades.) Run the engine at 3000 rpm while spraying water. Lots of water mist, not a garden hose stream, you don't want hydro lock, but seeing steam out the exhaust is good. Use this method only if you cannot do the following method.


Second simplest way is using the windshield washer system to pump the water into the intake air stream. You can source a spray nozzle. I just used a small diameter soft copper pipe that I smash down enough to be a nozzle. Make a separate power source for the washer pump with a switch that you can operate while driving. I have found the best results are when I can put the engine under load, up a long incline, at about 3000 rpm ( what ever your car is at 55 to 60 mph ) . Start by running the pump for about 15 seconds at a time. If the motor loses power, you have gone too long. I ran 4 gallons through a motor over 90 miles.


So, run a lot of water through it and see what you got. Nothing to lose at this point. Almost no cost to try this.

Water Injection for cleaning

__________________
Greg
2012 S350 BlueTEC 4Matic
2007 ML 320 CDI
2007 Leisure Travel Serenity
2006 Sprinter 432k
2005 E320 CDI
1998 SLK230 (teal)
1998 SLK230 (silver)
1996 E300D 99k, 30k on WVO
Previous:
1983 240D, on WVO
1982 300D, on WVO
1983 300CD, on WVO
1986 300SDL 237k, 25k on WVO (Deerslayer)
1991 350SDL 249k, 56k on WVO - Retired to a car spa in Phoenix
1983 380 SEC w/603 diesel, 8k on WVO
1996 E300D 351k, 177k on WVO

I believe the water injected turns to steam. Steam cleaning has some use on Carbon.

Will it tackle vegetable oil residue? I just do not know. I do suspect it has to be chemically attacked with a solvent. Dissolved and washed out.

Adding a bottle of marvel mystery oil to the engine oil can help this situation. If it is going anywhere with a soak. A small amount will get on the cylinder walls adding the solvent into the ring lands.


Takes substantial miles though and prior indications have to be the earlier soak down really did help the compression.

Yes, this works but as mentioned it takes time and you mustn't skip steps else you'll make things worse .

Marvel Mystery Oil works pretty well but Kano Labs in Tenn. sells better stuff, it *might* be called "KREEM", I've forgotten .

Yes, WVO cokes up and scores cylinders, this was what ruined the engine in my '84 300CD, it was so bad I had to re sleeve the cylinder block to save it (damned hippies) .

If you're planning to save this car it's time to do the long cylinder soak thing and begin looking for a wreck or rusted out parts car as this engine is clearly on it's last legs .

I ran a 240D OM616 with maybe 200 # compression and in California's warmish weather it always started even down to 40 degrees F., I made sure it had good injectors, proper valve adjustment, clean filters and fresh fuel .

It sure was slow though .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

Amazing idea! Just read through the thread, very surprised more people dont use water injection.

__________________
04 Sprinter 3500 - 320k
84 190D 5spd - 870k
"Ich mag die Dieselgeräusche"
https://youtu.be/YjrxHqNy5CQ
✞

Would you mind giving me the dummies low down on how to do this? I'm interested as well, my 300SDL shakes and smokes, might as well try this before throwing in the towel.

__________________
1998 Ford Escort ZX2 5 speed - 279,000 miles My Daily

1992 Mercedes 300D 2.5 202,000 - Pure junk
2000 Mercedes E320 Black - 136,000 miles - Needs repair

Don't forget to grease the screw and threads on the spring compressor.

Read this tread: Cheap Water Injection
The first post on this thread tells you how to do it and the part # for the nozzle. You will not need the pressure switch, just a manual push button will be enough for what you are going to do.

__________________
Greg
2012 S350 BlueTEC 4Matic
2007 ML 320 CDI
2007 Leisure Travel Serenity
2006 Sprinter 432k
2005 E320 CDI
1998 SLK230 (teal)
1998 SLK230 (silver)
1996 E300D 99k, 30k on WVO
Previous:
1983 240D, on WVO
1982 300D, on WVO
1983 300CD, on WVO
1986 300SDL 237k, 25k on WVO (Deerslayer)
1991 350SDL 249k, 56k on WVO - Retired to a car spa in Phoenix
1983 380 SEC w/603 diesel, 8k on WVO
1996 E300D 351k, 177k on WVO

Have to chime in just to agree with my experience a engine with 200-220psi compression will still start no problems with working glow plugs and run just great. Definitely give the water injection a try. I wouldn't write the engine off just yet...

__________________
1978 300D, 373,000km 617.912, 711.113 5 speed, 7.5mm superpump, HX30W turbo...many, many years in the making....
1977 280> 300D - 500,000km+ (to be sold...)
1984 240TD>300TD 121,000 miles, *gone*
1977 250 parts car
1988 Toyota Corona 2.0D *gone*
1975 FJ45>HJ45
1981 200>240D (to be sold...)
1999 Hyundai Lantra 1.6 *gone*
1980s Lansing Bagnall FOER 5.2 Forklift (the Mk2 engine hoist)
2001 Holden Rodeo 4JB1T 2WD

In combination with a fuel system in questionable condition. All bets are off. Both the engine and fuel system need cleaning to find out where you are.

No sense in working the fuel system if some more reasonable compression numbers cannot be gained first. Personally I have a good spare 240d engine.

Even if I did not hopefully I could locate one reasonably priced and in good condition and swap it. If the rest of the car was in reasonable condition.

For a lot of past wvo users the parts of the equation overall just did not add up well. So the cars went to the wreckers.

Easy access to good used components at reasonable prices. For these models is regionally dependent . There is close to nothing left in my region. To add further to the problem. Shipping costs have increased steadily. American buyers have much, much cheaper shipping costs to deal with in general.

What is always an unknown is effective compression at higher than cranking RPMs. For example slightly leaky valves will reduce compression.

Once the engine is running they may function better. Just less time to allow their slow leakages to have as great an impact. .In my early days some well worn engines produced more effective power. Then they ever had when in better condition. Actually this was a good indication they were usually getting near their end of serviceability.

Greetings!

After a hiatus I was able to come back to this project fresh. Despite relatively low compression numbers, I believe that the engine should be able to start and run. I decided to test the fuel system more thoroughly as follows.

I connected spare injection lines to the IP. Then I connected the injectors to the spare lines so they sprayed outside of the engine into plastic containers where I could watch them. With a friend cranking, (long enough to fill the injection lines), I observed that only the 2nd cylinder injector was spraying. Then, I removed the injectors from the lines and cranked again, noting a squirt of fuel coming from each and every open injector line as the engine cranked. Must be the injectors, right?

Well I contacted my mechanic, who lent me 6 spare used injectors to try out. I replaced ALL 5 and yet again the 2nd line was the only one that sprayed. To be sure, I switched # 2 and 3 injectors, and confirmed 2 was still the only one that sprayed, regardless of what injector was connected to the line.

So working the fuel system from the injectors backward, I believe this test confirms that there is an issue with the pump. Before I tear it out and swap in another and run the test again, what do y'all think? Is my test sound? What would cause the IP to only reach popping pressure on the second line alone? Thanks everyone!

Was the car running on all 5 cylinders when it quit on you? If it was running on all 5 prior to the failure, it's highly unlikely that the IP is the culprit unless you had some truly heinously foul fuel in there.

You have 3 things that can cause failure of high pressure delivery:
- Clog in the system preventing filling of the delivery element
- Scored pumping elements leaking down more than they're pumping
- Stuck or pitted delivery valves that don't maintain pressure in the hard line

It goes without saying, but air in the hard lines can prevent popping the injector. It should bleed out on its own if the IP is pumping fuel.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Sounds like the wvo may have polymerized inside the IP, and that has gummed up the works.

Disconnect the injector hard lines at the IP.
You should get decent fuel flow out of the delivery valves when cranking the engine.
If not, disconnect the glow plug relay and run ATF through the IP.

Let the ATF soak in overnight and repeat with fresh daily ATF soaks in the hopes that you can eventually clear out the gunk.
Might take a week or more to see any positive results.

__________________
78 W116 300SD 'Desert Rose' new as of 01/26/2014
79 W116 300SD 'Stormcloud' RIP 04/11/2022