i got a 1977 chevy with a 350 knocking the motor just got rebuilt about 5 years ago and it has been parked from about 2 and a half years it has not been drove much well we moved the timeing and then it started kocking well i cut it off and come back about a hour later and fired it up and it did not well we drove it all day yesterday and it did not but this moring when i went out and drive it it started knocking agine i got pretty good oil PSI so idk know what to do next ???????
2007-04-06 01:52:14 · 13 answers · asked by jd_farmer_sc_2006 1 in Cars & Transportation ➔ Car Makes ➔ Chevrolet
try a higher grade of gas ,on some old cars that i have owned if i used a lower grade gas the engine would knock
2007-04-06 01:57:20 · answer #1 · answered by Anonymous · 1⤊ 2⤋
There are very few electronics on a '77 and the 350 is a very good machine.I really like the '77, hope you have the hard top, I really like the two bullets and the fins.
For the knocking. I would give a 90% probability you have a vacumn problem. The 350 uses a vacumn advance for the timing. Since you indicate that this is an intermitant problem I would start there. There is a vacumn diaphram connected to the distributor. Remove the hose and be sure that is in good shape, if there are cracks you won't build any vacumn. If that is good, have someone rev the engine a little, you should actually see the distributor turn, that is how the engine advances the spark.
2007-04-06 02:04:16 · answer #2 · answered by ttpawpaw 7 · 1⤊ 0⤋
What I would do is take a piece of wood. (broom handle, 2x2) you get the point. Start the engine and place one end of the stick to your ear and the other to some where on the motor. You need to avoid the moving parts. (fan and belts)See if you can determine where the knock is coming from. You can also use a stethoscope. Check by the fuel pump. If the knock is loudest there then the fuel pump spring is week and slapping on the rod inside the motor. Change the fuel pump.
2007-04-06 04:20:01 · answer #3 · answered by Glenn L 1 · 0⤊ 0⤋
Well for one thing YOU DO NOT MOVE YOUR TIMING GEARS!!!! If your timing isn't your problem....which would be a suprise. (There are other ways to advance or retard your timing.) Then you should look at your valves next....Reset your valve timing (with feeler gauges). After this if you still have problems...you inspect the pistons for witness marks of the valves and check your crankshaft to be sure it is true. Inspect your mains and Rod bearings for premature wear. These are the only places you can have knocks. I am assuming that your pistons are still connected to your rod and firing. Enjoy!
2007-04-06 12:18:22 · answer #4 · answered by Anonymous · 0⤊ 0⤋
Years back my 86 K 20 pickup sat for several months. I started it up and it sonded like it had a rod knock. I shut it right down. Wondering what the heck could have caused it, my buddy was standing there and said pop the distributor cap off. I was like what the hell for? He said trust me, I popped it off. Didn''t even take it out just flipped it over with the wires still attached. All the contacts had big chunks of carbon yellow crap built up on them. I cleaned them all off, and put it back on. Started it up and no more noise.
2007-04-07 02:36:05 · answer #5 · answered by Blazin 5 · 0⤊ 0⤋
By not hearing the sound or which part of the engine it's occurring, it may be a cam chain rattling on the cover or there is a wrist pin failure. Competent engine rebuilders replace cam chains, pistons & pins, however if you received a DEAL on the rebuild, chances are those items weren't addressed.
- - -
2007-04-06 02:07:31 · answer #6 · answered by Mr. T 7 · 0⤊ 0⤋
Knock Knock.Maybe you should answer it.
But on a serious note,What kind of knock, tinnie ? top? bottom ? You need to find roughtly where it's knock then you can start eliminating things more info will help better.
2007-04-06 02:02:28 · answer #7 · answered by shelley 1 · 0⤊ 0⤋
pull the plugs and check the cap wires rotor and plugs you are looking for any signs of burning cracked wiring, or signs of misfires... start there first, and change anything that doesn't look right... If that doesn't help them compression test that engine and check your vacuum lines, and timing advance... If that doesn't fix it then start looking at fuel and air filters, If that still doesn't fix it, then have the engine looked at for internal damage.
2016-05-18 03:50:41 · answer #8 · answered by ? 3 · 0⤊ 0⤋
Your fuel-air mixture may be too lean if your timing is correct. The compression may be too high for available gasoline, which could prove difficult to fix. You may have too change pistons, or if you're lucky, thicker head gaskets just might lower the compression enough.
2007-04-06 02:04:24 · answer #9 · answered by ? 5 · 0⤊ 1⤋
Check to make sure there is enough oil in the engine. Just because it has good pressure doesn't mean it is entirely full.
2007-04-06 02:02:54 · answer #10 · answered by Anonymous · 0⤊ 1⤋