QuestionI have a 1962 Lincoln gas welder it has the Continental F162 4 cylinder engine in it. My question is this I bought this welder used about a month ago and didn't really notice a knocking noise when I got it, I guess I was just so excited to get it. Well the engine starts up great no problems with starting but when it is running at idle it has about 15 PSI of preessure and will fluctuate rapidly it also has what is like a knocking noise in it. I tried disconecting each spark plug wire while it was running to narrow down where the noise is, it is all around number 3 piston. Now do you know would this be a bearing problem or a oil pressure problem maybe? if it is a bearing problem what should I do?? Thanks
Chris
AnswerI believe what you have is failed bearing - it is causing both the variation in oil pressure as the crank turns, and the knocking noise.
The only way to fix this is to drop the oil pan and inspect all the main and rod bearings visually - I think you will easily spot the problem that way. In fact, it is probably bad enough that you can feel the looseness by shaking the rod end back and forth crosswise to the crank, but if it is a main bearing, you will have to disassemble the whole bottom end of the engine to get at it well enough to fix it. The reason is that the crankshaft has to come out to be re-ground, then new bearings will be needed to put it back together. If you are not used to rebuilding engines, you can take the engine to any automotive machine shop (ask for a recommendation at your local NAPA store or other reputable auto parts place (not one of the el-cheapo chain stores!) - they will send you to a good machinist. The rebuild will cost some money, but you will have an engine that will run for many, many years.
If you've rebuilt other engines, you will find this one a pleasure - they are small, simple and easy to work on.
If the damage to bearings is minor, you will find bare brass showing in the inserts, and not much damage to the crank surface - in which case you could buy a stick of "Plastigauge" at your local auto parts place and check the oil clearance of each bearing - but if you find any clearances larger than 0.0025", it's time to fix it before it gets worse, or even throws a rod through the side of the crankcase. If it is 0.003" or less, you can try installing undersize bearings, but make sure it still turns by hand after you do this - making them too tight is worse than too loose!
I advise you not to even run the engine until you do this - I think you are way beyond the Plastigauge and quicky patch job stage - you are near to throwing a rod, from the symptoms you describe.
Good luck - I think you are going to need it!
Dick
