305E in Illinois
 

Hello-

Anybody have a good guy that knows the 305E V6 engine in Northern Illinois / Southern Wisconsin? I have a crazy knock out of the blue that I can't chase down. She was running beautifully but then started a gradual knocking. Suspect some kind of lifter noise but I am not a mechanic... I do have some valve lash over tolerance which I am going to adjust next time I'm in the garage, but may need a solid valve job or other more technical help.

Thanks in advance.

Phil
1964 GMC C1000

Re: 305E in Illinois
 

An easy possibility to check is ignition timing. Maybe you will get lucky. Good luck.

Re: 305E in Illinois
 

Your best bet here would be to upload a video (Youtube) of your engine while it is running. There are three major areas of concern when it comes down to engine knocking noises. you have mentioned one, and that is lifter noise. Two more are connecting rod and main bearing (crankshaft related) knocking noises. One more would be a loose wrist pin knock. Please upload a video. We will then be able to steer you in the right direction.

Re: 305E in Illinois
 

Like Jim and George said, your best bet for a mechanic is you and us, neither of which are mechanics haha.
BUT We can talk you through just about anything and these aren't complicated engines. The only thing you might run in to is a parts availability issue. Start with the easy things.

1. Take a video and post it up on youtube or rumble or some random site.
2. Buy a 10.00 timing light and check your timing.
3. Check your oil level because low oil will definitely give you a knock/tick.

Re: 305E in Illinois
 

Did you pull or replace the spark plugs? Or removed the air cleaner?

Re: 305E in Illinois
 

Timing is pretty close. When I use a seascape I can here it best in front of the edistributor closer to the carb with scope on top of the valley pan. Plugs are new as is pertonix module, coil, plug wires. I put in a American autowire upgrade kit as well. Trying to upload a video. Also- i recently found some valve lash well over spec so I am adjusting that soon.

Re: 305E in Illinois
 

Timing is pretty close. When I use a stethoscope I can hear it best in front of the distributor closer to the carb with scope on top of the valley pan. It does not sound down deep to me, but what do I know! Plugs are new, as is pertonix module, coil, plug wires. I put in a American Autowire upgrade kit as well. Trying to upload a video. Also- I recently found some valve lash well over spec so I am adjusting that soon. Oil level and pressure is good too.

It seems to be running quite well other than the knock- no great vibrations or grinding noises anywhere.

Appreciate the comments.

Re: 305E in Illinois
 

It's probably an exhaust leak....manifold or pipe. I assume you have checked the oil and plugs for color. Assume no backfire at carb or exhaust. Starts and runs good, no major missing/stuttering. No smoke.

Also there is nothing special about our V6 motors as far as finding someone who "knows" them. It's a standard internal combustion carb and points motor. It has tune up, timimg and valve adjustment specs on this forum. Nothing different to troubleshoot than a Chevy V8. Etc.

Re: 305E in Illinois
 

Yes Azken,

Seems to start and run fine with no backfires. Can and Exhaust leak sound like metal on metal knocking??

Re: 305E in Illinois
 

Definitely, some exhaust leaks can really throw you off while trying to pinpoint the location of the noise.

The best trick that I've found to locate noise is to take a long flathead screwdriver and use the blade to put pressure on the engine while listening to the handle with your ear. Once you get the hang of it you'd be surprised how you can pinpoint noises. Use a screwdriver with a solid handle (hard plastic works good), not one with a rubber handle.

To locate noises coming from the valvetrain, put the screwdriver on the valley cover and valve covers.

To locate noises from the bottom end, crawl under the truck and put the screwdriver against the oil pan with the engine running.

Good luck!