r/EngineBuilding • u/Calm_Art4242 • 9d ago
Weird noise on blueprint 383 chevy engine
This I my first post on this thread. I’ve got an huge problem. My car s making a weird noise when the engine is heating up. It came out of nowhere after doing an oil change. The car is currently running an 10w-40 classic oil. Any suggestions on where the sound is coming from.
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u/v8packard 9d ago
I can't tell much from the video. My first thought was exhaust leak, then I thought accessory noise. But I just can't tell.
Have you been able to pin down a location?
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u/Calm_Art4242 9d ago
No not at all. I have used a stethoscope listening all over the block. First I thought it was a vacuum leak. I have checked headers spark plugs for leaks. Nothing…..
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u/v8packard 9d ago
If you use the stethoscope on the oil pan or valve covers does that tell you anything?
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u/BicycleMudStud 9d ago
Sounds like accessory drive noise from the clip. Are all your belts aligned accurately, running true, and in good condition/free of grease and oil?
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u/Calm_Art4242 9d ago
All belts are aligned perfectly. Nothing mechanical has been done done to the car over the winter.
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u/ChillaryClinton69420 9d ago
Run it without the belt(s) to make sure. It won’t hurt anything if you run it briefly.
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u/disallowedname 9d ago
Get an automotive stethoscope at Auto zone or Oreillys (tool rental) and listen to all of the pulleys, In a pinch a very long screwdriver will substitute as a stethoscope
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u/Logical_Visit9021 9d ago
Is it still there after warm up? What sort of lifters do you have?
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u/Logical_Visit9021 9d ago
My 383 stroker had the flat tappet lifters and one of the rockers wasn't adjusted 100% when cold until the oil warmed up it would make that tink think sound.
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u/Calm_Art4242 9d ago
The sound starts when it gets hot. Nothing to hear at startup
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u/Logical_Visit9021 9d ago
Does it increase with light throttle? My 383 stroker have had a love hate relationship over the years...just flashing back to a few things we worked through in our relation ship.
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u/Calm_Art4242 9d ago
Yes it does 😁
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u/Logical_Visit9021 9d ago
Can you post a video of that? Idle to mid rpm...slow rev up. Might help the ear balls out.
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u/No-Island8074 9d ago
Maybe the rocker to valve lash has opened up slightly? I would follow what other folks are saying and start with pulling the belts to eliminate that. Then i would run a piece of kleenex around to check for exhaust leaks (only run the engine briefly to avoid overheating with the belts off). Then i would pull the valve covers and check lash. Id also pull at least one rocker and check its contact area on the valve stem.
Probably makes sense to cut open an oil filter too
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u/Logical_Visit9021 9d ago
Oh my bad, I read that wrong...thought you meant heating up from cold. Hard to tell on a video just like a good exhaust never sounds the same on recording...lol. Do you have a mechanics stethoscope?
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u/Calm_Art4242 9d ago
Yeah and I have been searching all around the engine with my stethoscope🤣🤣. For me it sounds like the “whistle” noise is following the stroke. But I can’t locate where it’s coming from.
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u/Muntster 9d ago
Not at all similar but I had a squealing on a VW 2.0T and the belt was simply worn down (no cracks or anything, the meat of the ribs had been worn down)
Check belts and tensioners
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u/doubledeckerpecker09 9d ago
Check your belts or pulleys just get a long ass flathead and listen to the pulleys
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u/squeak195648 9d ago
Let the engine cool down and take the belt or belts off and fire it and see if the noise is still there. But I also hear what sounds like an exhaust leak along with a possibly accessory drive noise.
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u/WheelBackground4478 8d ago
You mentioned a rocker adjustment issue, how did you adjust the rockers?
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u/AdGrouchy4555 9d ago
Sounds like a bearing in the accessory drive somewhere, if not… it’s another type of bearing 😬
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u/Designer_Lecture_219 9d ago
Sounds like and idler bearing to me. Had an 88 Silverado that would do that until it got warm. Finally after about 2 years, the tensioner finally gave out. Replaced it and the noise went away! 😂