2003, 4.6l engine just recently acquired a ticking noise, coming from the passenger side. Thinking it was lifter, I replaced all of them, but the back 2. I'll have to figure this out. Before I buttoned everything up, I ran the engine and the noise was still there. The noise sounds like a tick and when you shut the engine off, the noise sounds like a rattle coming to a halt.

Thought is might be a idler, so I removed the serpentine belt. Noise still there. I'm not sure, but I think it is coming from the passenger side, close to the firewall, and behind the intake manifold.

Can anyone give me any ideas? Would be greatly appreciated.

 

A leaking exhaust manifold gasket will make a ticking sound. Just something to check.

 

Loose sparkplug maybe
Pcv valve rattling

 

I'll check plugs. Could be possible. Valve cover is currently removed. Not hooked up. At this point I have to eliminate everything.

 

I just had the same problem. It might be the air conditioner compressor clutch. You can check it by turning the switch to defrost, and listening for the ticking to start and stop. If it on ticks wile the compressor isn't turning then replace the clutch.

 

Thank you. In my first post, I posted that I removed the serpentine belt. A/C clutch will not turn without the belt.

 

Possibly the exhaust manifold gasket??

 

If it is an exhaust manifold gasket, would you hear a rattle noise when you shut the engine off?

 

Mine didn't do that. The sound was louder at cold start up, and got quieter as the system warmed up probably due to the metal expanding and closing up the gap. It was tough to locate, but if have a piece of small tubing like an old brake line, attached a rubber hose to it and use like a stethoscope to locate the sound.

Look for broken or missing studs as well. I had to have the manifold replaced because it was warped.

 

When I probe with my Stethoscope, the loudest and most prevalent sound is coming from the catalytic convert inlet pipe just down stream from the exhaust manifold. Right under the O2 sensor. Older vehicles had a "donut". Are all connections now just a cast round with a flared pipe?

Check out the video and help me distinguish where the noise is coming from.

https://www.dropbox.com/s/s68a8b8tsh...91546.mp4?dl=0

 

Mine started ticking just before it blew out a plug (loose plug)

It may also be possible the rattle on shutdown is a different noise.

 

I replaced the lifters on that side (passenger) of the engine thinking it was a lifter noise. Wasn't. While I was there, I removed the spark plugs and re-installed them. Not the spark plugs. Rattle may be catalytic converter.

 

I taped my shop vac hose to the exhaust pipe and ran the shop vac on exhaust. Took a spray bottle with soap in it and sure enough, bubbles coming out of the #1 port and connection of the exhaust manifold and catalytic converter.

Just thought I'd let everyone know to do this first when looking for noise.

 

Clever idea!
I take it that there would be too much heat to spray it with the engine running to be effective?

 

Might be okay on the start up, but the shop vac lets you watch the bubbles grow and pen point exactly were the leak is coming from. Doesn't take more than 2 minutes to tape up the shop vac.

I also check the opposite side while I was doing it.