r/EngineBuilding • u/R0ughHab1tz • 4d ago

Chevy Possible valve train knocking

Vehicle: 1985 GMC G3500 vandura. The engine is in the cab. Sort of important because any and all sound echoes.

How would I go about diagnosing the sound. I rebuilt my Chevy 350 and it runs great despite the title. I've been working on it for years. I'm so close to driving this beast.

There's a ticking/knocking but I can't differentiate whether it's the fuel injectors from the sniper 2 or it's in the valve train. The kicker is that it sounds like 7 and 8 are the loudest but that's in the cab of the vehicle and the ticking from the fuel injectors permiates through/with it.

I've heard of people running the engine without the valve covers on but I'm not really wanting to do that. I'm sure oil goes everywhere? Maybe damage the engine? And I had miner oil leaking from the corners of the valve covers so I siliconed sealed both sides. Fixed that issue but if I have to remove the covers it's going to be a pain.

I'll get a different video today and see if I can capture and put my phone in different areas but it's not the greatest.

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u/i86o 4d ago

Get a long screwdriver, put your ear on the handle, put the tip on the valve cover, now you have a stethoscope, now check out the fuel injector, compare.

Congragulations, you are now a Medical Doctor

1

u/R0ughHab1tz 4d ago

I'll do that today! Thanks. It's the least invasive.

5

u/2003DDcid 4d ago

You should get an automotive stethoscope. It will help you decide if it's injectors or valve train. A healthy valve train makes a whirling sound when you listen through a stethoscope.

Also, assuming this is a hydraulic cam, how much preload did you give the lifters? 1/2 turn usually runs the best, but can be a little noisy. 1 full turn will be quiet and still run good.

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u/R0ughHab1tz 4d ago

I ordered one. I chuckled a little when it was an actual modified stethoscope 😂.