617..........WVO engine..........won't start - Page 3 - PeachParts Mercedes-Benz Forum

jt20 · #1 08-25-2009, 09:34 AM

Quote:

Originally Posted by Ian White

And why would they be stuck in the sprung in position even if the engine turns over fine ( albeit a little slow but never the less). What am I missing?

its my understanding that two things may happen which could be identified as stuck rings.

-cylinder walls wear with use and become slightly tapered. When a piston is left unlubricated for a long period of time in one position, the ring may stick in the piston's grooves and not expand as it reaches the wider upper section of the cylinder bore.

-a ring can stick in the piston's grooves by being restricted from rotating / twisting due to build-up. See how the rings in the pictures have a face that only contacts the cylinder wall completely if the piston is traveling in a certain direction?

It is quite easy to imagine that with the use of WVO, that many of the piston grooves are filed with crud from the contaminating remains of incomplete combustion.

Ian White · #2 08-25-2009, 02:39 AM

Engine turns over fine but im thinking It has stuck rings beacuse the low low low compression numbers and also the fact that the mechanic I bought it from said it had sat a year or more, Compression numbers are:cyl 1: 76 psi, cyl2: 49 psi, cyl 3: 111 psi, cyl 4: 145 psi, cyl 5: 151 psi

ANY help is appreciated!

IW

t walgamuth · #3 08-25-2009, 06:01 AM

It could be so. I don't see how the numbers could be so low from normal wear. I would remove the injectors or glow plugs and put in a few teaspoons of Marvel Mystery oil and let it sit for a week at least and then try towing it to start it. Let it set for a month if you have the patience.

Good luck.

Be sure to turn it over with the injectors out to get the liquid out of the cylinders first.

(with those low figures you may need to add mmo every day as it may run right past the rings).

Could be valve sealing issues too....or both.

jkubica · #4 08-25-2009, 06:17 AM

Quote:

Originally Posted by Ian White

Engine turns over fine but im thinking It has stuck rings beacuse the low low low compression numbers and also the fact that the mechanic I bought it from said it had sat a year or more, Compression numbers are:cyl 1: 76 psi, cyl2: 49 psi, cyl 3: 111 psi, cyl 4: 145 psi, cyl 5: 151 psi

ANY help is appreciated!

IW

Hi
If an engine is badly overheated, the piston rings can become weak (soft)and result in low compression numbers.
Joseph

dieseldan44 · #5 08-25-2009, 07:20 AM

Quote:

Originally Posted by Ian White

Engine turns over fine but im thinking It has stuck rings beacuse the low low low compression numbers and also the fact that the mechanic I bought it from said it had sat a year or more, Compression numbers are:cyl 1: 76 psi, cyl2: 49 psi, cyl 3: 111 psi, cyl 4: 145 psi, cyl 5: 151 psi

ANY help is appreciated!

IW

Ian,

Are you confident in your test setup? All 5 of those readings are really, really low.

Could you verify your compression tester somehow on another vehicle (preferably another 617)?

dd

Biodiesel300TD · #6 08-25-2009, 11:34 AM

A teaspoon of brake fluid will also unstick rings. Leave it in for atleast over night, but a week would be better. I've used this trick a number of times. I just used it this spring and brought a cylinder back from 85psi to over 300. So it works. Make sure you crank the engine over with all the injectors out to blow out the fluid that may still be in the cylinder before you do another compression test.

Also adjust the valves, tight valve clearences cause low compression.

barry123400 · #7 08-25-2009, 12:22 PM

The engine just sitting a year or two would not normally do this in my opinion. I have let 616 and 617 engines sit for years with no difficulty.
Now if excess dampness has caused the piston grooves or rings to oxidise is another story.

I have only converted one engine back from vegatable oil that sat around for a couple of years unused. So my experience is almost zero. No difficulties were experienced in my case.

The bore fit is usually close enough on a diesel to retain a film of oil somewhat. This was the only reason I ever was able to come up with at least. Of why a gas engine sitting will tend to seize and an average diesel much less so.

First as mentioned verify the compression gauge is working properly. If the rings are gummed up that bad with waste vegatable oil the engine did not run prior to being pulled in my opinion. I just see no way that senario was possible. Unless the gum already present on the rings solidified with time sitting perhaps.

The temper removed from the compression rings on these particular engines could happen but the engine would have to be driven a fair distance with the coolant blown out I would think. It would never restart after that type of event. The compression would be far too low to start on if as indicated.

Order of attack if I was involved personally.
#1 check the cam to harmonic balancer marks. I might also remove the cam bolt and visually have a look at the key and keyways. Highly unlikely but again something I might look at.

#2 verify the compression gauge. This is probably the most important. And should be the first step.

#3 only if the above items check out first start a soak. Plug the block heater in if the engine has one and do not spare the soak.

#4 You did not observe by any chance mist being blown out the intake at any point? This is a really long shot as well. Not to ask it would be an error though.

#5 I have seem pictures of cylinder bores on engines burning wvo that have very badly scored walls yet never thought about the actual cause. The effect seems to not hit all cylinders equally. That pressure gauge still has to be a prime suspect.

#6 try to locate the last owner of the engine before the garage got it. That individual may have some useful information.

Diesel911 · #8 08-25-2009, 01:22 PM

I have used the Mervel M. Oil on my Volvo and it worked. But I used more thatn a teaspoon.
The thing about the Marvel M. Oil is that you can run the Engine afterwards with no ill effects. I my case I moved the Car from my front yead to the back so I could change do the Oil Change in my drive way.
If I had used Brake Fluid I would have been stuck Jacking my Car up in the dirt.
Here is recent success story:
Compression Test...how low is low.....

Ian White · #9 08-25-2009, 02:39 PM

Some of the valves were tight and some were loose theyre al at spec now. I have the marvel oil and will try it out. The tester is a matco and a snapon. I used to different gauges with the same results.

barry123400 · #10 08-25-2009, 03:51 PM

Well this sounds like about the ultimate possible test of the marvel mystery oil so far. Do not be in too much of a hurry as the solvent takes it's time. Sorry it turned out to be compression related.

winmutt · #11 08-25-2009, 04:16 PM

Surprised the numbers are that low across the board, its almost impossible.

Outofworkjoe · #12 08-25-2009, 04:45 PM

Look up Auto Rx,works very well.

Ive used it 4 of my past cars and no problems,cleans very slowly.I like to go on bobtheoilguy,for more info on MMO/Auto Rx/Seafoam/berrymans b12/ and so @ so.

#13 08-25-2009, 06:40 PM

You have gotten the correct recipe for the attempt at unsticking the rings if that's the problem. I would use MMO, but I've never tried brake fluid. I don't know why or how it would work, but don't argue with success.

The main reason that I chimed in was to make SURE that you are well aware of the consequences of turning over the engine without the glow plugs BEFORE putting them back in. If you forget and put them in before blowing as much fluid out of the cylinders as possible, you will bend, break or crack something.

Just trying to make sure that you know this.

Good luck with it.

Diesel911 · #14 08-25-2009, 08:43 PM

Quote:

Originally Posted by LarryBible

You have gotten the correct recipe for the attempt at unsticking the rings if that's the problem. I would use MMO, but I've never tried brake fluid. I don't know why or how it would work, but don't argue with success.

The main reason that I chimed in was to make SURE that you are well aware of the consequences of turning over the engine without the glow plugs BEFORE putting them back in. If you forget and put them in before blowing as much fluid out of the cylinders as possible, you will bend, break or crack something.

Just trying to make sure that you know this.

Good luck with it.

It has be 30 years or so but I have seen Brake Fluid damage a paint on a Car when left over night. I believe there is something in it that could eat up Carbon.
I might try soaking one of the stock Injector Nozzles that I have that has carbon plugging up the central Pintel Hole and the cross drilled hole and see if it loosens it; and if Pop-testing afterwards will clear the carbon out.

oldsinner111 · #15 08-25-2009, 09:57 PM

Use 2 gallons type F ATF to 18gals. fuel.Find hills mountains and drive hard for 200 miles.After valve adjustment.