The Stovebolt Site Forums The Shop Area General Truck Talk My motor is pinging!

I bought a 55 Chevy truck that has been sitting for 8-9 yrs. I changed all the fluids and the plugs and got it running. It sounds half way descent when it is idling in neutral but when I put it in gear and give it gas it lugs and pings.
The plug wires are new. I plan on changing my rotor cap next maybe my modulator. What else could it be?

might wanna check the timing on it, clean out the carb,clean out the fuel filter,check the points, condenser,,,just a few thoughts, good luck with it,,Fred..........sometimes when I hear pinging I think of the timing or running to lean but sometimes a pinging may mean just a noise to someone..

Cap, Rotor, Coil, Plugs, Wires, Points, Condenser, fuel filter, flushed gas tank, and be sure to gap the points and plugs correctly.

Those have become the automatic things I do to a old truck when it's been sitting for any length of time.

I've tried to go the cheap route in the past, just replacing the stuff that "looked" bad, or was missing all together, but it just ends up being troubleshooting nightmare, and results in multiple trips to the auto parts store.

So when I bring a truck back from the dead.. even if it's running when I get it.. those things get replaced with new, right off the top.

Really, if you think about it, they're just typical "tune up" parts that you should probably replace once a year or so anyway.. and for most trucks, you can get it all at AutoZone for under fiddy bones.

I agree, and will replace those parts as soon as I can I just hope the problem is not internal.
Thats my biggest fear. I will just keep doing what I have been doing "trial and error" type of stuff.

rogpatt - you have the right idea. experimentation and educated guesses are the name of the game. it is kind of irritating when you have to spend a week fixing something, but when it finally works right it is a satisfying thing. my truck was doing sor of the same thing, the lugging anyway, turned out to be fuel filters. put in 2 new NAPA golds and it runs like a dream. anyway, good luck.

Roger,

Pinging, in the mechanical vernacular is the sound made by the fuel/air mixture pre-igniting, or igniting too soon BTDC. If you are actually hearing a ping, it is most likely a timing related problem.

I think pre-ignition can be caused by carbon deposits in the cylinder/piston area, or a sharp worn valve surface (hot spots) but on a probability scale, these would be right down at the bottom.

Tune it up and fiddle with it..it will probably run great after that.

Stuart

Is there a possibility that you are 1 tooth off on your distributor? If not, excessive wear in the cam timing (chain or gears) will cause it to either ping on backfire thru the exhaust.

To check your cam timeing for slack or excessivew gear play, take off the distributor cap, roll the engine backwards until the timing mark reads zero, then have someone watch the rotoras you slowly rotate the engine the other direction. when the rotor starts to move, stop and read the timing index. if it is more that 6 degrees, install a new timing set. This will greatly improve both power and economy.

Good luck

It was my carb that was causing my truck to ping and choke. I took off my carb, disassembled it, cleaned each piece, and blew air thru it. Put it back on and imediatly saw the difference. Thanks for youy help guys and leading me in the right direction. I never thought it could be the carb. Guess you learn something new every day. Now for my next obsticle and I know there will be one (like I said this truck was sitting in a garage for 9 yrs untouched)!