It got down around 28-30 early this morning, so I plugged in my block heater for about 2 hours. It is still working, since it made my radiator start to drip like it does when the engine is warm, and it started smoothly like it was warmed up, but there was a pronounced knock for a couple seconds:
(I try to remember to turn on my dash cam first so it can catch things like this!)
It was impossible to tell where it was coming from, ie injector or crankshaft/rod. It went away as you hear in the video and it didn't come back. I moved over to the dump station promptly and shut it off to drain and rinse my tanks (took at least 15 mins due to the rinsing). When I started it again, no knock that time. A sort of normal thing sometimes, or...? Maybe the fuel filter got a bit gelled or something?
I drove 25 miles on the highway after the second start up and I didn't hear any knocking. I finally remembered to check the oil when warm (though it was an hour after shut off) and the oil is slightly overfilled from the oil change I gave it about 3 weeks ago, but only about 1/8" past the full line (at the vertical line in the "F" in "Full"). I've cold started and driven it a dozen or so times since the oil change (several times after 30-50 min highway drives) and that's the first time I've heard it. It was parked for 3 days so it may have just been an injector knock from the cold fuel, though it started perfectly on the first try and didn't sputter or seem like it was missing but maybe it still fired on the cylinder ok despite the injector complaining.
Or maybe a lifter/rocker due to cold oil?
The knock lasts 2 seconds or less and only on the first cold start, so I'm not TOO concerned since it went away once the oil started flowing, but I still wanted to ask. I will see about draining a tiny bit of the oil so it's not overfilled, in case that's somehow the problem.
I suppose it could even be a bad glow plug, and one cylinder isn't firing properly for the first couple of seconds? It has been starting fine without the block heater, but since I had free electric, I plugged it in to help avoid strain on the starter and batteries after the cold morning, because why not? For what it's worth, the cold timing advance is functioning properly.
And come to think of it, I have heard an odd noise before recently when cold starting (but less cold than lately), but it wasn't a loud knock like that. It sounded sort of "hollow" before but less loud. An old thread I saw on OB said that could be an injector/cyl not firing. https://www.oilburners.net/threads/hollow-thump-on-cold-start.54568/
Well, I guess I won't worry about it unless it gets worse since it's starting and driving fine.
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(I try to remember to turn on my dash cam first so it can catch things like this!)
It was impossible to tell where it was coming from, ie injector or crankshaft/rod. It went away as you hear in the video and it didn't come back. I moved over to the dump station promptly and shut it off to drain and rinse my tanks (took at least 15 mins due to the rinsing). When I started it again, no knock that time. A sort of normal thing sometimes, or...? Maybe the fuel filter got a bit gelled or something?
I drove 25 miles on the highway after the second start up and I didn't hear any knocking. I finally remembered to check the oil when warm (though it was an hour after shut off) and the oil is slightly overfilled from the oil change I gave it about 3 weeks ago, but only about 1/8" past the full line (at the vertical line in the "F" in "Full"). I've cold started and driven it a dozen or so times since the oil change (several times after 30-50 min highway drives) and that's the first time I've heard it. It was parked for 3 days so it may have just been an injector knock from the cold fuel, though it started perfectly on the first try and didn't sputter or seem like it was missing but maybe it still fired on the cylinder ok despite the injector complaining.
Or maybe a lifter/rocker due to cold oil?
The knock lasts 2 seconds or less and only on the first cold start, so I'm not TOO concerned since it went away once the oil started flowing, but I still wanted to ask. I will see about draining a tiny bit of the oil so it's not overfilled, in case that's somehow the problem.
I suppose it could even be a bad glow plug, and one cylinder isn't firing properly for the first couple of seconds? It has been starting fine without the block heater, but since I had free electric, I plugged it in to help avoid strain on the starter and batteries after the cold morning, because why not? For what it's worth, the cold timing advance is functioning properly.
And come to think of it, I have heard an odd noise before recently when cold starting (but less cold than lately), but it wasn't a loud knock like that. It sounded sort of "hollow" before but less loud. An old thread I saw on OB said that could be an injector/cyl not firing. https://www.oilburners.net/threads/hollow-thump-on-cold-start.54568/
Well, I guess I won't worry about it unless it gets worse since it's starting and driving fine.
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