502mpi engine noise
08-04-2009, 01:07 PM
#1
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Thread Starter
502mpi engine noise
The saga continues with my mild build 502 mpi. It now has 8 hrs on it since rebuild. I now have the moisture in the breathers fixed with the new tail pipes, and the crankcase ventilation fixed with proper breathers and routing. The motor runs good, and is strong. I have a couple of minor oil leaks i'm trying to search for, but they are elluding me.
The noise that is concerning me is what i would call a knock, but not sure the sound. It really does not sound like a tick for lifter noise, but i do not have trained ears for an engine. I only hear it after a hard long wot run and the oil temp is up at 220-230. If i raise the hatch at idle, i hear it. I only hear it at idle, never when the rpm's are up. If i raise the throttle slightly from idle, it get's faint as well. I'm not sure if it's a lifter or not. If i shut down for awhile and restart say a 1/2 hour later, I don't hear it, or it's very faint. When the engine is cold, warm, I don't hear it.
I know i can hear the same sort of sound on my truck at idle, the boat is a little more pronounced. The engine builder wants to recheck my lifter preload. Said he goes 3/4 turn from 0 lash, and wants to put it at 1 to 1 1/4. Says the last couple of years of crane lifters needed more preload for some reason before they went out of business. He doesn't think it's rod bearing otherwise it would be doing it all the time. . . .
I plan on isolating the internal tip flappers tomorrow by keeping them full open and taking the boat for a test ride, but i don't think those are it. They are full rubber coated, no metal exposed.
Any ideas??
The noise that is concerning me is what i would call a knock, but not sure the sound. It really does not sound like a tick for lifter noise, but i do not have trained ears for an engine. I only hear it after a hard long wot run and the oil temp is up at 220-230. If i raise the hatch at idle, i hear it. I only hear it at idle, never when the rpm's are up. If i raise the throttle slightly from idle, it get's faint as well. I'm not sure if it's a lifter or not. If i shut down for awhile and restart say a 1/2 hour later, I don't hear it, or it's very faint. When the engine is cold, warm, I don't hear it.
I know i can hear the same sort of sound on my truck at idle, the boat is a little more pronounced. The engine builder wants to recheck my lifter preload. Said he goes 3/4 turn from 0 lash, and wants to put it at 1 to 1 1/4. Says the last couple of years of crane lifters needed more preload for some reason before they went out of business. He doesn't think it's rod bearing otherwise it would be doing it all the time. . . .
I plan on isolating the internal tip flappers tomorrow by keeping them full open and taking the boat for a test ride, but i don't think those are it. They are full rubber coated, no metal exposed.
Any ideas??
Last edited by cloudmaster_321; 08-04-2009 at 01:22 PM.
08-05-2009, 01:28 AM
#3
Registered
moisture in the breathers can be caused by either not running a hot enough oil temp, allowing the heat to burn off condensation in the oil, i.e. more than 212*F oil temp, or from a leaking intake gasket, blown head gasket, or bad reversion from a big cam.
Gold Member
08-05-2009, 09:11 AM
#5
Registered
The saga continues with my mild build 502 mpi. It now has 8 hrs on it since rebuild. I now have the moisture in the breathers fixed with the new tail pipes, and the crankcase ventilation fixed with proper breathers and routing. The motor runs good, and is strong. I have a couple of minor oil leaks i'm trying to search for, but they are elluding me.
The noise that is concerning me is what i would call a knock, but not sure the sound. It really does not sound like a tick for lifter noise, but i do not have trained ears for an engine. I only hear it after a hard long wot run and the oil temp is up at 220-230. If i raise the hatch at idle, i hear it. I only hear it at idle, never when the rpm's are up. If i raise the throttle slightly from idle, it get's faint as well. I'm not sure if it's a lifter or not. If i shut down for awhile and restart say a 1/2 hour later, I don't hear it, or it's very faint. When the engine is cold, warm, I don't hear it.
I know i can hear the same sort of sound on my truck at idle, the boat is a little more pronounced. The engine builder wants to recheck my lifter preload. Said he goes 3/4 turn from 0 lash, and wants to put it at 1 to 1 1/4. Says the last couple of years of crane lifters needed more preload for some reason before they went out of business. He doesn't think it's rod bearing otherwise it would be doing it all the time. . . .
I plan on isolating the internal tip flappers tomorrow by keeping them full open and taking the boat for a test ride, but i don't think those are it. They are full rubber coated, no metal exposed.
Any ideas??
The noise that is concerning me is what i would call a knock, but not sure the sound. It really does not sound like a tick for lifter noise, but i do not have trained ears for an engine. I only hear it after a hard long wot run and the oil temp is up at 220-230. If i raise the hatch at idle, i hear it. I only hear it at idle, never when the rpm's are up. If i raise the throttle slightly from idle, it get's faint as well. I'm not sure if it's a lifter or not. If i shut down for awhile and restart say a 1/2 hour later, I don't hear it, or it's very faint. When the engine is cold, warm, I don't hear it.
I know i can hear the same sort of sound on my truck at idle, the boat is a little more pronounced. The engine builder wants to recheck my lifter preload. Said he goes 3/4 turn from 0 lash, and wants to put it at 1 to 1 1/4. Says the last couple of years of crane lifters needed more preload for some reason before they went out of business. He doesn't think it's rod bearing otherwise it would be doing it all the time. . . .
I plan on isolating the internal tip flappers tomorrow by keeping them full open and taking the boat for a test ride, but i don't think those are it. They are full rubber coated, no metal exposed.
Any ideas??
08-05-2009, 12:03 PM
#6
Registered
Thread Starter
I have been following your project. Glad to see you got your exhaust straitend out. Sounds like a lifter adjustment issue or a berring. If you were running with bad oil from the reversion issue you may have damaged something. When I had my problems with reversion I spun a berring and broke a crank in two. All of my berrings had scoring and severe wear. Cut your oil filter open and examine the oil. If you see shinny metal that is not good. You can also get a oil annalisis. Good luck, keep us updated.
Last edited by cloudmaster_321; 08-05-2009 at 12:38 PM.
08-05-2009, 12:05 PM
#7
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Thread Starter
I have been following your project. Glad to see you got your exhaust straitend out. Sounds like a lifter adjustment issue or a berring. If you were running with bad oil from the reversion issue you may have damaged something. When I had my problems with reversion I spun a berring and broke a crank in two. All of my berrings had scoring and severe wear. Cut your oil filter open and examine the oil. If you see shinny metal that is not good. You can also get a oil annalisis. Good luck, keep us updated.
08-05-2009, 12:41 PM
#8
Registered
I would at least take it easy on it till you know for sure. If somthing blows it does a lot less damage at lower RPM than WOT. Hopfully you caught the reversion problem before any damage was done. I ran mine several hours after replacing the cam, I then noticed the low oil pressure, that was too late. I changed the oil and the pressure went up but then then the next trip out it blew.
08-05-2009, 01:53 PM
#9
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Thread Starter
I would at least take it easy on it till you know for sure. If somthing blows it does a lot less damage at lower RPM than WOT. Hopfully you caught the reversion problem before any damage was done. I ran mine several hours after replacing the cam, I then noticed the low oil pressure, that was too late. I changed the oil and the pressure went up but then then the next trip out it blew.
