Mysterious Ticking

[Z Ya Later]

I have noticed a ticking from the motor when it runs. It almost sounds like the valves moving, but not sure. Its fast and somewhat quite. Is this normal? I know it needs an oil change, but I'm hoping this is not serious.

[RangerBob]

Change the oil /nm

nm

[AmericanZ28]

Could be a bad spark plug wire, but its probably nothing serious. Is it a continous and steady?

[KnightFire]

Could be a simple plug wire, exhaust leak or...the valve train. Is it constant or does it change with the engine's RPMs?




KnightFire

[Injuneer]

Add fuel injectors to the list. Try "listening" to each injector with a stethoscope (or short piece of small diameter pipe) and see if one or two are louder than the others. If you think you have found a noisy one, pull the harness connector off to verify. Noisy injectors are not necessarilly a problem.

To check the plug wires, put the car in a dark location and open the hood while its idleing, and look for sparks along the plug wires. Might see a faint blue glow, but there shouldn't be any actual sparks. If the wires have never been changed, a few "leaks" would be likely. Sparking wires need to be replaced.... each spark you can see means a cylinder didn't fire like its supposed to.

[Joe K. 99 Zeee!!]

While I would put exhaust manifold leak at the top of the list, I've also heard stories of loose spark plugs too.

I've had 2 exhaust leaks at the headers and they usually sound mechanical, and speed up frequency and increase in volume with increased throttle.

[Z Ya Later]

The speed of the ticking changes with the speed of the motor, which makes me think that its the valves. Even at idle its a constant pace and the plug wires are supposed to be fairly new. However, the oil is probably getting old and it was pretty black when I checked it and half a quart low. I'm going to switch it to Royal Purple and see what that does.

[Joe K. 99 Zeee!!]

Both of my exhaust leaks almost had me fooled that it was the valves. I took mine in almost immediately to be on the safe side. Either way, I don't think an oil change will make a difference. Not saying you shouldn't, but don't expect the sound to go away.

[Z Ya Later]

Well, she's scheduled to go in on Wed., so I'll have them check that out along with the ABS. Thanks for the tips guys.

[DJ 95 Formula]

As Joe mentioned

There is possibilty of a loose plug. I had a ticking...that was never loud. I couldn't pinpoint it. Thought I had checked everything. Then one day on the interchange. BOOOOM!!! Blew a plug right out. Sounds so horrible....bringing tears to my eyes just thinking about it.

Oh yea, and a local GM dealer didn't locate it either. They told me it was my valvetrain.

Anyway, its just a thought. Doing the heli-coil wasn't fun.


DJ

[Z Ya Later]

Thanks for the possibility DJ, but one question...did the ticking change with the engine speed or remain constant?

[DJ 95 Formula]

changed

with engine speed it did.

DJ

[Z Ya Later]

ok, thanks for the tip

[bigdaddyvu]

ticking time bomb?

I had my 350 rebuilt and I install a high volume high pressure oil pump and it ticks pretty bad when its cold. but if your unsure where the sound is coming from. use a couple of feet of fuelline while the engine is running place one end to your ear and one end to the engine and scan for the loud ticking sound. that should help you find it.

[JL8Jeff]

LT1's like to make ticking noises. My old 93 did and it would come and go from time to time. It always got a little quieter after an oil change so it could have been the pump, a lifter or a valve. The LT1's are know for piston slap as well, but that is usually noisy at a cold startup and goes away as it warms up. The injectors are very noisy as well. And an exhaust leak will give you a ticking sound too. Has your gas mileage suddenly gotten worse? If so, I would guess you have an exhaust leak. But exhaust leaks usually seal themselves up as the engine warms. I had 74K miles on my car when I sold it and 40K was with a supercharger so the ticking never did do any harm whatever it was.