Got a 350 sbc in a 48 chevy and i've noticed over the past week or two i've got a tapping/ticking noise when i lift off the throttle when driving it. I don't get it at idle..... Any idea's what it might be?
I've had a few sbc noises dip stick in backwards hitting crank Rockers hitting valve cover pushrod that lost the end piece at only did it as i puilled to a stop light fan belt deteriorated and flapping against pulleys Good luck i figure to get in before the "sounds like a wiped out cam to me" guys lol Best best is to have a buddy rev the engine while you look at listen on both sides
Haha thank you dooley, I read an old thread on here and I noticed all the guys saying "you've wiped out a cam" guys
Sounds like it's coming from the engine, not the driveline? As the load shifts from driving to driven u-joints and diffs that are about to go can start to make odd noises like that. If it's an automatic, maybe the flex plate.
Yes it sounds like it's from the engine, don't think it's a driveline issue I'll check it out tomorrow.
I have similar elusive tick, drives me nuts, I've been all over the top end, no finding it. My dad had one as well, turned out on his it was a bent connecting rod, and don't ask me how that would make a ticking noise.....
I had a ticking noise in my 283 looked at all the normal things lifter, rocker arms, cam could not find any thing. The noise would get louder under acceleration and quite off when I let off, After a couple of days we pulled the engine found a broke rod bearing not a turned but broke, the number 5 top bearing was broke about a inch from the tap. The motor had been in and ran for about two and half years just started one after noon while out driving. Good luck man
This must be the day for SBC engine noises. I was just reading this: http://www.foxvalleymarc.com/Tech_section/troubleshooting_engine_noises.html
If it only does it during deceleration and you've eliminated the more obvious stuff... Check the engine and transmission mounts and check any exhaust or linkages that run close to the body or chassis. Look for any witness marks like like shiny metal where there should be paint or rust. Check for loose converter bolts or cracked flex-plate. Try running it with the fan, alternator and/or P/S pump belt removed. Check for cracked or broken fan blades or a loose fan. Check for excessive end play and side play in the water pump.
had a broken exhaust manifold do the same thing , the lack of engine noise at idle made it more noticable plus the motor rolling over helped push it together sealing the crack .
I'll check through it today and see if I can notice anything, I'll give you guys an update later on tonight. Thank everyone
I've had a sticky lifter since the engine was rebuilt and I've never bothered to follow it up or replace it. I just live with it now.
"Left a wrench in the valley"....haha. Been there, done that! Check the fuel pump first, then the flex plate. Being a SBC, it could be a cracked piston......
Well I took the car out about an hour ago and I only really get it when I get up to about 50mph and i'm backing off the throttle....so not really sure what it could be still. I'm going to try the hood ornament bolt see if that makes a difference but i'm sure it's coming from the engine bay.
My SBC in my '36 Ford had a soft rapid ticking only when decelerating. Drove me batty for 4 years. Finally pulled the engine and had it rebuilt professionally. Reinstalled it and drove it for one more year, still had the same clatter when I lifted. Pulled the fuel pump one balmy Sunday morning and the bright sunlight picked up a shiny reflection inside the hole in the block. There it was, HALF OF THE FULCRUM spring laying in the hole, broken off, but the other half now cocked at an angle riding on the fuel pump. I cant figure out how it ran so well with only half a crooked spring working the fulcrum arm. Threw on the new fuel pump, noise gone.
If it does it mainly on deacceleration, that leads me to believe it is connecting rod/bearing/piston related. When you are accelerating, or holding a steady speed, there is a load on them, taking up some of the slop. But when you let off the gas, the piston and rod assembly are kind of floating or put under a different kind of load. Guy who has a shop next to our shop has a pickup with a sbc in it and he asked us to listen to it one day. It was ok revving it up, but when he let off the gas, you could hear it sort of knocking. I said piston was my guess. A week ago, he stopped by and told me they tore the motor down and found one bearing and the wrist pin on that piston had slop in them. Also, check your convertor to flexplate bolts. Weird noises come from them being loose. Don