ejt6125

Hey guys, stalker here, first time poster and Im computer challenged so I hope I do all this right. Here we go, 1998 Mustang GT 66,000 miles. Noticed a tick, knock under the passenger side valve cover (sounds like). Really not sure what to make of it, rockers, lifters, exhaust leak, valve, even heard water or moisture in spark plug bays. I had recently washed engine before sound started (read, noticed). Here is what Ive done so far, added a little Marvel oil to my engine oil and gas tank. Purchased 5 30 Royal Purple to make an oil change this weekend, will be substituting a half quart of oil for a half quart of synthetic trans fluid per suggestion of trusted mechanic. (to free lifters if that's the case) The day before I noticed the tick, I had placed an order for new plugs and wires, should be in Friday. I will know then if water or moisture is an issue there. In the video you will hear the sound tapering off after the engine is cut, one mechanic seems to think that narrows it down to lifters or water/spark plugs theory, but eliminates valve. I am very interested to hear any input. This is my daily driver, Im just going easy on her at least until oil change and plugs and wires get swapped this weekend. Hopefully this is the link to the video on youtube: also, while running pulled each spark plug wire and sound continued each time. eliminates plug issues??

ejt6125

Tick continues cold, warm, hot, never seems to change with engine temp and does follow rpm.

bronxbomba63

At the expense of sounding like an idiot, did you remove the valve covers? Because is sounds like a pebble or something rattling around and then "rolling" to a stop when you cut the engine off.

ejt6125

No I have not taken off the covers. I was thinking that if I didn't solve it this weekend, I would have my local shop do that and take a look. Felt it was a little out of my scope of mechanic abilities. But, I guess there's no harm in pulling the cover, maybe something will jump out at me.

dawson1112

It sounds like something is continuing to rotate after the engine is stopped.
I would rule out any valve train , exhaust, or spark plug problems because they just wouldn't continue to rotate like that once the engine stops.

So you have to look at what can possibly rotate after the engine is stopped.

Maybe a problem with the ac clutch/or compressor. Pwr steer pump, water pump.
Try removing the belt and run the car for a short time 15 20 seconds should be enough to find out. If your noise disappears you know you have an accessory problem. If the noise continues you have to look else where. Trans? is it manual or auto?

ejt6125

Man trans.

ejt6125

As far as the belt goes, it seems to still be making noise once the belt completely stops for a second or two.

JJ Glo

Sounds like a stripped spark plug bouncing up and down.

ejt6125

I would love for it to end up being a plug.

dawson1112

Yes I understand that and normally any noise would stop once the engine and belt stop rotation.

In your case it doesn't which leads me to believe that a component in one of the pumps has either broken or cam loose and continues to rotate a few seconds after engine shut down.

Manual trans could be the throw out bearing retainer sleeve has come loose and continues to spin for a moment.

I am highly skeptical of a plug continuing to bounce around for a full 2-3 seconds after compression and engine rotation stops. As well as any valve train components.