"Buzzy" Engine

honda
accord

#1

Hello everyone. I’ve got a 2002 Accord with a 4-cylinder engine with 90,8xx miles. For a while now, its been pretty rough and buzzy (not as glass smooth as it once was). Nothing seems out of the ordinary and everything seems fine otherwise, but just the other day, I stopped at a red light and I couldn’t feel the engine. I thought I stalled, but I looked at the gauges to see that it was indeed running, but as smooth as melted butter (It hasn’t run like that since the car was new!). After making it back home, the car was back to its old rough and “buzzy” self. So, my question is: Is there anything that I can do to return the engine to its glass-smooth idle? Its been tuned up with new plugs, wires, rotor button, and cap, but (all with oem parts too). I had almost forgotten how nice and refined this car was!


#2

Maybe a vacuum leak from a cracked fitting that happened to close up for a while?


#3

Hmmm, I didn’t know that a vacuum leak could cause a rough engine. If there is a leak, it can’t be big because the power brakes still maintain their vacuum for what seems endless.


#4

Oh yes, it can do that, and it doesn’t have to be big. A leak big enough to interfere with your power brakes would likely kill (stall) the engine.


#5

The power assist for the brakes only relies on a portion of the vacuum available in the intake manifold. There are other areas where this won’t have an impact on your brakes, and for it to be bad enough to impact the brakes, your engine wouldn’t be running.


#6

Maybe a bad motor mount.


#7

You could have a loose heat shield that’s vibrating most of the time.


#8

“I thought I stalled, but I looked at the gauges to see that it was indeed running, but as smooth as melted butter (It hasn’t run like that since the car was new!). After making it back home, the car was back to its old rough and “buzzy” self.”

Don’t think so. That wouldn’t make it run rough. I’m with texases on this one.


#9

Well, it could be a shield, they can be good noise makers, but yes, would have no effect on actual engine smoothness.

Always hard to diagnose over a keyboard and screen!


#10

It could very well reside in your plugs and wires. I have seen too many bad plugs rite out of the box to not suspect them…I would look into wires first and then a plug. When it is running rough… Pull one wire off a plug at a time you should notice a change in engine pitch or see it vibrate…if it makes a change…then that wire/plug is NOT your issue…The wire that makes no change when you pull it is your culprit… IF you find such a wire/plug then determine if it is the Plug, Wire, OR fuel injector that is causing the problem.

I would replace the plug first, then wire then lastly and most unlikely the injector. Could be that you have a dirty injector too which can be cleaned with Techron injector cleaner usually… I am suspect of the plug wire setup myself…easy enough to prove out.

The issue being intermitent is a good clue that it may be a wire with a crack in it shorting to ground from time to time…These you can usually spot at night by looking at the wires under the hood

A VERY COMMON MISTAKE is that the wires are not in proper contact with the plugh electrode…Many X you need to “Slip” the wire down into its boot so that you hear and or feel a SNAP when it goes onto the plug…look into that for sure…many x the wire is short thru the boot and you need to slip more of it down so it can get onto the plug properly. If it is loose enough and not snapped onto the plug properly the voltage will short to ground inside the plug well… This also happens when you have a leaking valve cover gasket and the plug wells fill up with oil…then the voltage shorts because of the oil …not as common but happens