2DASEA
Veteran Member
- Joined
- Dec 21, 2011
- Messages
- 78
I finally got the nerve up to try an "easy" fix on my Cat 3406 with a oil slobber/consumption issue. Some history first: Low hour rebuild, which wasn't broke in properly by the P.O.. Determined the sleeves were glazed after removing the valve covers and exhaust manifold I observed valve guides good and while running the engine without the manifold on(smokey!) I saw oil coming up from the cylinders rather than down from the head.All holes appeared wet. Options here: Lift engine and trans (4000 lbs +-) enough to drop pan for new cylinder packs. (rather not) or try the Bon Ami trick described to me by an old school Cat mechanic. Here's the theory, by introducing a small amount of BonAmi to the intake while running at operating temp the light abrasives in the Bon Ami will clean off the glaze and polish up the rings a bit, and finally help seat the rings. Apparently Cat had a part number for this stuff at one time and was used often to seat rings on rebuilt motors where the rings weren't seating. I figured I really didn't have much to loose, My mechanic friend said I would have little to worry about the stuff getting down into bearings and doing any damage, and I figured if it didn't work, well back to the ring job! So with Bon Ami in hand, I slowly introduced the stuff right into my Turbo, (yikes, Yes i was fighting every cell in my body to do this!) I put in about a table spoon, let it run a few minutes, and then another. I was running about 2/3 engine speed water temp 175.I was pulling hard against my dock lines. The engine never coughed or bogged once. In all I bet I ran a cup of the stuff through there over about an hour. First thing i noticed was a diminishing smoke from un-done breather tube. Well, I ran it a while longer, and then shut her down. The test to see how successful this experiment was would have to be at the next cold start.
The next day I went down to the boat, fired her up, and to my delight the blue smoke that usually chugged out of the exhaust was down to what I would expect as normal for this motor on a cold start. The real sense of victory came when I returned to the engine room and discovered that the oil,usually dripping from the slip-joint at the exhaust side of my turbo was completely gone!!! Yee Haw! I still need to take her out and run the $&#@ out of her to really seat those rings in but so far I'm delighted to report that Bon Ami worked! I would not try this on a modern diesel with the tight tolerances of today but my old 1976 vintage slobbering beast took it well and has saved me a whole heap of work. Bon Ami only and no other cleanser or abrasive should be used. It is made mostly of egg shells I think and advertised guaranteed not to scratch glass!The other cleansers may be harmful to bearings etc.
The next day I went down to the boat, fired her up, and to my delight the blue smoke that usually chugged out of the exhaust was down to what I would expect as normal for this motor on a cold start. The real sense of victory came when I returned to the engine room and discovered that the oil,usually dripping from the slip-joint at the exhaust side of my turbo was completely gone!!! Yee Haw! I still need to take her out and run the $&#@ out of her to really seat those rings in but so far I'm delighted to report that Bon Ami worked! I would not try this on a modern diesel with the tight tolerances of today but my old 1976 vintage slobbering beast took it well and has saved me a whole heap of work. Bon Ami only and no other cleanser or abrasive should be used. It is made mostly of egg shells I think and advertised guaranteed not to scratch glass!The other cleansers may be harmful to bearings etc.
