odd slobber

[mike90045]

Yes, it comes from the fuel tank bolt, on the water jacket (cylinder).  I suppose it's found a crack in the casting, and blowing by the head gasket, and weeps out the bolt threads.   I guess pulling the bolt and adding thread sealer would "hide" the problem, but the root cause of high pressure going somewhere it shouldn't, still exists.  Maybe retorquing the head bolt will stop it ?

suggestions ?  New head gasket ?  new cylinder jacket ?

photo album: https://www.facebook.com/media/set/?set=a.446238508782941.99946.120212794718849&type=1&l=b14ddf17fd

[xyzer]

Mike,
We polish these things and they look so nice......then they start getting used. I would wipe it off and keep an eye on it and see what happens. If it is running fine add that to the summer fix it list. It is in an unusual place. I would suspect water in that area before oil.

[dieselgman]

Reminds me a bit of a French-made John Deere 6-cylinder that we had a bunch of trouble with... it kept blowing oil behind the flywheel and we thought we had main-seal problems. After replacing the seal a second time, we realized that the bell housing bolts were threaded all the way into the block and the bolt threads were weeping from the crankcase pressure. We had to clean and re-seal those threads - problem solved. The amount of oil thrown out was fairly dramatic and you would not think that could happen past fine threads with thread lock compound on a bolt torqued to 80 ft. lbs..

In your case, you are probably seeing either a head gasket leak as suspected, or maybe crankcase pressure migration up the cylinder stud in that corner of the head. In either case, that bolt is probably bored into a casting void or simply bored too deeply.

You are not necessarily seeing the results of high-pressure there. Even a few psi of crankcase vapors can cause an alarming amount of black gunk to build up in places you would not expect.

dieselgman

[BruceM]

That's very mysterious.  There's no oil where that bolt goes- just coolant.  If you don't see bubbles in the coolant when it's running, then it can't be exhaust slobber/head gasket leak, right???

I'd try sealing the bolt threads after cleaning out the hole. Permatex gasket maker would be my first choice, though it would need 24 hrs before use.  Even though I can't understand how oil (!!!)  is coming out of the threads.

You might get an answer by pulling the head, the next time that is needed.

Best Wishes,
Bruce

[Tom]

That the hole for that bolt bottoms into the hole for the head bolt. I suspect that the oil is coming up from the crank case via the head bolt passage and out through that bolt. The fix would be to remove the head bolt from the block and put some permitex #2 on the threads. Interesting that bolt also has a lot of threads above the nut. In this case what I'd do is drain the coolant, loosen all the head bolts. Then take one of the head bolts off and use it as a jam nut on the one with the long threads. Use it to pull the stud so you can put the permitex on the threads and reinstall the stud.

I see the belt is now running outside the grooves. How is that working???

Tom

[mike90045]

I see the belt is now running outside the grooves. How is that working???

OK for now, it seems like the genhead pulley likes the belt half on the rim. no wear showing, but I'm sure it's only a matter of time before I have to do something.

If I goop up the bolt threads so it's sealed, and not goop the stud thread, the drool will find another path to pollute, so for now, I'll keep wiping up the muck.  Maybe it will stop itself ?   And now I'm wondering if I should swap the bronze idler gear into it, or wait till summer to tear into it.  Of course, if the steel gear sheds teeth before then .....

[dieselgman]

And now I'm wondering if I should swap the bronze idler gear into it, or wait till summer to tear into it.  Of course, if the steel gear sheds teeth before then .....

On the idler, do you have excess slack or other indications of a problem? Lister put out something on the order of 500,000 of these engines over the years with iron or steel idlers, and did not identify that as a significant problem.

It should be realtively easy and painless to pull the one suspect stud and see if those threads are indeed the culprit - a little sealant could go a long way.

dieselgman

[BruceM]

Tom's observation on the amount of threads above the nut for that head bolt is a good one, I think. I missed that.

I'd want to pull that head bolt myself, in hopes of getting the bolt to go further into the crankcase as well as to check the threads for leakage. It's also possible that the leak is not around the bolt threads, but around the shim gasket under the cylinder. 

I'd also check out the crankcase vent situation- if you've got positive crankcase pressure, this will not be the last source of oil leaks.

Either way, sealing the small bolt might be adequate to stop the leak completely.

[ronmar]

On the idler, do you have excess slack or other indications of a problem? Lister put out something on the order of 500,000 of these engines over the years with iron or steel idlers, and did not identify that as a significant problem.

Lister also properly positioned the idler hole in the case to properly establish gear mesh/backlash...  The indians have not been so precise in this area...

[dieselgman]

Lister also properly positioned the idler hole in the case to properly establish gear mesh/backlash...  The indians have not been so precise in this area...

Right, best to assume the worst until proven otherwise for the Indian clones... this was the reason for my question about excess slack (or any metallic shavings in sump). You can generally tell pretty quickly if there is an issue there. 

dieselgman

[toydiesel01]

I have a Metro 16/1, My engin leaked in the same place.  I  believe it was comming from the Head gasket.  When my head gasket finally went, I removed the head and found high spots.  I flat filed the high spots off, installed a new head gasket and tightened the head nuts using 11/4 inch socket and a 3 foot pipe.  I let the engin run up to normal tempture (with coolant) and retightened the head nuts again I got about an 1/8 of a turn more.  The bad head gasket was putting pressure into the water jacket.  I may have had more pressure because my engin has a water pump.  After changing the head gasket the slobber has not come back yet.

The longer stud is ok because this is where Metro used an eye bolt ( for lifting I guess). It screws onto the stud.  My engin had the eye bolt attached  when I bought it(new in the crate). The only thing I used the eye bolt for was to help stablize it while moving it

If/When you remove the head check your water jacket ports (some of mine were 3/4 clogged with flash from the casting.
You could also see that the head gasket and the ports do not align correctly, this makes it very eazy to get a leak.     

[mike90045]

The longer stud is ok because this is where Metro used an eye bolt ( for lifting I guess). It screws onto the stud.  My engin had the eye bolt attached  when I bought it(new in the crate). The only thing I used the eye bolt for was to help stablize it while moving it
 

I've got the 1 long stud, but a 1 1/8 socket fits it with just a bit of slop. I got a 6 point deep impact socket, so it's not going to round that off. ( note to Tom - B&B hardware in Ukiah has their line of ALLEN tools, on sale 40% off)

 Any idea on what that thread size is, if I wanted to put an eyebolt on there, is it SAE, Metric, or something else ?

[mike90045]

coolant tank appears to have no bubbles (checking with a mirror and flashlight, or else I have to stand on alternator while running  ) and coolant has no oil film on top.  Crankcase looks OK, just dirty oil after 5 hours!  I'll keep wiping it up, and see what happens.

re idler gear.   Existing gear seems ok, but I've got fuzz on the sump magnets. Who knows where it may have come from.  What's the lifetime on the steel gear where the indians punch marked it?  I wonder if I need to change it out before summer teardown?  And , after I pull it, is there any heat treatment / anneal protocol that can be done to return it to service, or use as spare?

[dieselgman]

On the idler gear, in my experience it is not normal for the Indians to have punch marked that gear at all- who knows about your specific Metro though. You would have to inspect closely for that as well as abnormal gear wear or excessive gear lash.

A slight amount of fuzz during initial break-in might be considered normal for one of these. During the first few hours and during initial loading you should be wearing quite a bit on rings and cylinder walls until they are seated. This will be ferrous iron that will stick to your magnet/s. If it continues beyond that initial 25 hours, then it might indicate a real problem to resolve.


dieselgman

[dieselgman]

If we were dealing with known metallurgy in your timing gears, then some heat treatment protocol might be applicable. This is not likely the case with most Indian Listeroid manufacturing.

As I understand it, initial forging temps are done in the neighborhood of 1800+ degrees F, and subsequent stress relief treatment (after machining) is done around 700 to 800 degrees F. These are only very general ballpark numbers though, and thorough testing would be required to achieve the desired results to any consistent degree.

dieselgman