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| | | Forums66 Topics128,051 Posts1,055,734 Members48,426 | | Most Online14,466 Apr 26th, 2026 | | AD Chevy Trucks Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
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on the Internet for over 30 years! and not clogged down with Ads! Again, thanks! | | | | Joined: Jan 2009 Posts: 14 Apprentice | | Apprentice Joined: Jan 2009 Posts: 14 | I have a '51 Chevy Truck with a '61 235. It has been running great the past few years. Last night I went to put it in the garage, and upon start up there was a very loud, rapid knocking sound. I shut it down immediately. It was kind of a hollow sound; very rapid. Can anyone Help with a suggestion?
1951 Chevy 3100
| | | | | Joined: Jul 2001 Posts: 3,887 Cruising in the Passing Lane | | Cruising in the Passing Lane Joined: Jul 2001 Posts: 3,887 | pull valve cover and check rockers/adjustment, ignition off crank it and watch'em move, properly or not
Bill | | | | | Joined: Dec 2008 Posts: 1,922 'Bolter | | 'Bolter Joined: Dec 2008 Posts: 1,922 | X2 - could be 1 stuck valve, but watch your oil pressure!! | | | | | Joined: Jan 2009 Posts: 14 Apprentice | | Apprentice Joined: Jan 2009 Posts: 14 | Thank you for your Help so far. Since I am not a mechanic, I had an in-law who is come over this morning and listen to it. I started it up and the knocking stopped after 4-5 seconds. It initially ran rough, but smoothed out after the sound stopped. He said that his opinion was that the problem was a bearing located on the bottom of the piston rod, which connects to the crank shaft. However, to me the rockers and/or stuck valves also makes sense. And the rough running could be due to the carburator/choke combination. Could any of you give me additional help.
1951 Chevy 3100
| | | | | Joined: Jul 2001 Posts: 3,887 Cruising in the Passing Lane | | Cruising in the Passing Lane Joined: Jul 2001 Posts: 3,887 | maybe the later engine is a car version with hydraulics and a gummy lifter?
Bill | | | | | Joined: Mar 2002 Posts: 9,115 'Bolter | | 'Bolter Joined: Mar 2002 Posts: 9,115 | If you have a valve sticking open, it will cause a big miss and the push rod will rattle around. They don't usually recover from this but sometimes it does happen. | | |
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