I'm feeling some anxiety today, can't afford repairs
I can't do myself. I've rebuilt many types of gasolene engines but totally new to diesels. I can fix anything on old cars and motorcycles.
Help me diagnose this issue if you diesel
gurus here don't mind. I would appreciate it greatly.
I have a random ticking noise
occurring every few seconds. Imagine holding a marble sized steel
ball and tapping it against a steel
plate. It's definitively a “tick” or “tick-tick” each time it occurs, randomly but regularly. Cold or hot, at idle, 1500, 1800, 2100 rpms, in gear
3GM30F fresh water engine
with 1790 hours since installed in 1989. I've put 40 hours on it since purchasing
in mid summer last year.
I'm not concerned about the rods or mains, it's just not that type of noise
. It almost sounds external to the engine
but I spent several minutes looking, hoping, to find something external with no luck. It's a classic “tick” like a loose tappet on a solid lift
cam would make, but it's not regular. A singe “tick” or double “tick, tick” each time with a second or two or three between ticks.
.....as my anxiety level rises.
I ran it about 30 minutes this morning, decided not to go out for a sail on the bay. Strangely, the interval and rapidity of a “tick-tick” doesn't seem to increase in proportion to an increase in engine speed. It does increase slightly so this may be a red herring statement.
The only smoke I see is a very small puff just as engine speed is increased. Raise the throttle slowly and maybe no puff. Raise it quickly and a short puff occurs. Color is grey looking to me, sometimes darker grey, sometimes lighter grey. I don't think I saw any smoke in the past, but not sure I looked as closely as I have now.
Here's an important point, this started after a soft grounding last month. I ran the engine hard getting it off the bar. Not over revved, but 3100-3200 for several minutes at a time. Maybe four to six minutes then a few minutes at 1800 or sometimes idle while I evaluated the results. Then back to 3000+ for a few more minutes. It started to move the boat so I did this about four times I would guess. Finally got off when I took the weight of the anchor
and chain off the deck
. I notice the noise on the way back to the marina and I'm sure it wasn't doing this before the grounding. This engine has spent most of it's time at 2200-2300 RPMs while underway I would guess.
Engine runs smoothly and strong, offering no clue something is wrong except the tick. I've only recently realized it's OK to test full engine RPM
at the dock
and this engine will do about 3300-3400 wide open. I've done this once. Should do 3600 but it might be the condition of my throttle cable, it needs replacing. I'm not convinced it's capable of pulling the proper stroke length.
My plan right now is to change the oil
since it needs it anyway and adjust the valves. Hoping it's just a loose rocker. I'll look carefully for a broken valve spring as well, but it runs good to have a broken spring unless its just the top or bottom coil.
I think about the governor assembly on my old Ford 800 tractor and wonder if the governor could have a problem.
I think about how little I know about injector pumps and wonder if there is an issue there.
Any advice the members would like to offer is welcome.