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Nov 29, 2012 - Whenever I accelerate the car makes this rattling noise - it sounds like its coming ... When I stop accelerating (or only just slightly have my foot on the ... Try speeding up more gradually -- pretend there's a raw egg between ...
"Pinging" is the metallic rattling sound an engine can make when accelerating. ...environment in the form of nitrogen oxide (NOx) and raw, unburned hydrocarbons (HCs).... Daniel Dillon has twenty-two years of experience as a licensed Smog ...
if this is under the hood (front of car), it could be an exhaust heat shield that is either corroded loose or a fastener has come loose. Does it happen when you rev the engine in park? if so, either have someone rev while you watch for whatever is rattling or have them watch while you rev.
A KNOCKING SOUND IN THE ENGINE IS MOST LIKELY CAUSED BY ONE OF THE FOLLOWING
1. PISTON SLAP: Makes a sharp metallic noise. Idle engine and short out each cylinder plug. The noise will disappear when plug with bad piston is shorted. Noise will also disappear at acceleration. This can be caused by worn or out of round cylinder, or broken piston ring. Correct problem by re-boring cylinder and/or replacing piston.
2. VALVE NOISE: Makes clicking or rattle noise. Caused by excessive wear on valve stem or lifter, out of adjustment, or stuck valve. Correct by adjusting valve clearance, replace worn valve or lifter, regrind cam, replace valve guide and /or valve. A stuck valve can sometimes be loosened by passing oil through the carburetor while engine is running.
3. ROD BEARING KNOCK: Makes sharp metallic noise similar to a piston slap. Detection is opposite of piston slap. Rod knock is not heard at idle. Knock becomes louder as engine speed is increased. Caused by excessive rod bearing clearance. Correct by adjusting rod bearing clearance to .0015 inches by removing shims. May require re-pouring rod bearing.
4. REAR MAIN BEARING KNOCK: Makes dull knocking or thud noise. Detected at speeds between 20 and 50 MPH. Knock will normally decrease or disappear while pulling or decelerating. Noise will be detected the loudest at normal driving speed, when not pulling or decelerating. Correct by adjusting bearing clearance to .001 to .0015 inches. If knock is excessive, crank should be checked for out of roundness. May need to re-pour all main bearings to correct.
5. TIMING GEAR KNOCK: usually the most difficult to diagnose. If gear is loose or badly worn it will knock in all ranges. Run engine slightly above idle speed. Slowly open and close throttle. Knock will continue to be present, but just as engine slows down knock will become a slight rattle. Remove timing pin and reinsert into timing hole on timing gear cover. Press timing pin tightly against timing gear and accelerate slightly above idle. Knock will significantly be reduced or disappear. Correct by replacing both timing gear and crank gear as a matched set. The two gears should have a backlash clearance of .003 to .004. If more than .009 inch backlash, an oversize (.005) timing gear should be installed.
6. WRIST PIN SLAP: This can not be detected by shorting out the cylinder plugs. Rapidly accelerate and decelerate the engine speed. The engine will pass through a certain speed range when the wrist pin will rattle at about the same pitch as a valve tappet noise. This can be corrected by installing a new wrist pin bushing in the rod or new wrist pin f badly worn. Wrist pin should fit the piston and connecting rod with a tight metal to metal fit. The pin can be pushed into the piston and rod with a slight pressure of the hand. Pin to rod clearance is .0003 to .0005 inches.
Yes, it COULD be a timing chain rattling, but again, your guess is probably better than mine at this point.
Without the ability to hear the noise it is impossible to say. Noises can be very difficult to locate when you are standing right in front of the vehicle. It is completely unachievable to perform this task remotely.
Are you sure it is coming from the engine and not the transmission? Or maybe even the exhaust? It is not likely for a timing chain noise to go away as a reult of putting the transmission in gear.
As for the misfire, when does it occur? is it at idle? Is it when you are accelerating (putting the engine under a load? Does it only misfire at high speeds? Much more info needed here.
Your cataylic conveter is likely on the way out They rattle before they plug up . It may take 6 month or a year before it dose but it sounds like its going .However it also could also be a loose heat sheild on it so get under it and look look for anything loose that could rattle and even if it is the cataylic conveter you still have some time before it goes
Your getting backfires? hmm interesting. Seems like your engine is getting flooded and either purging it out of the exhaust or burning it all at once or both (backfire). Sounds like a leaky engine valve to me.There again the bluish smoke indicates to me thatyou are leaking oil somewhere- bad rings or head gasket maybe, which could cause a loss of compression which could also cause your problems.That rattling from the left/rear side sounds like a bad muffler try kicking the muffler (not hard though) next time you walk by it.