Ford Mod Motor: Timing Chain Tensioner, Lifters, Injectors, PTV contact, or exhaust?

[metroplex]

I'm trying to diagnose a noise problem that I'm experiencing and have been experiencing for at least 2 years (pre camshaft swap, pre intake manifold swap, etc...)

There's a "clack clack" sound that I hear that does not come from anyplace in particular but seems to be concentrated on the top end of the motor near the firewall (4.6L SOHC V8). You can hear it from the wheel well and underneath the engine but its loudest up top, center, and in the back.

I will hear this sound in the cold or hot ambients (0*F to 100*F).

It does not matter if the motor is hot or cold.

The only time I hear it is when idling at 650-850 RPM. As soon as I get on the throttle the sound goes away.

At partial throttle up to WOT, the sound is not "audible".

There's no rattling during the first cold start of the morning.

Anyone have any suggestions on how I can narrow down the search by elimination?

I now have CompCams XE262Hs mounted on my NPI heads.
I also have a revised Ford PI Intake manifold.
The engine is a 2000 4.6L SOHC V8 on a 2000 Crown Vic. I've logged 8000+ miles on the CompCams. The car only has 17,700 miles.

I had been running M1 5W-30 and even tried 10W-30 w/o killing this sound.
I'm now running on some SuperTech synth 5W-30 I had lying around.

It sees drag racing, daily driving, and long distance trips - definitely not a garage queen or trailer queen. If there's 16" of snow, the car is going to mush through it all.

I can try to provide as much extra info as needed.

I was just going to dump 5W-20 and 5W-40 to see if it'd help eliminate the sound.

 

[DirtyApe]

I had an incessant clacking sound in the exact same spots only at idle and it was the chain tensioner on the balance shaft. That was on a 4.0 v-6 SOHC though.

Sure sounds to the letter what you describe.

 

[punisher]

4.6 have several sounds that can be annoying.

Fuel injectors can cause a "clack/tick" sound, you can unplug the connector to each injector in the problem area and see if the noise changes. Don't run it too long with an unplugged injector or you will get a misfire code.

Some 4.6s had problems with lash adjusters not working properly (collapsing). Loose rocker = noise. Once in awhile we could catch the problem child running a relative compression test.


Are you sure it is not an exhaust "tick"? Any change if the engine is loaded up in gear?

Tough to tell with all of your aftermarket components. (EDIT: reread post, I see it was pre mod also)

Usually timing tensioner noises occur right after startup (in combination with oil filters with crappy anti-drainback valves).

mh2800, I know what you mean. I forget how many tensioners I had to slam in those 4.0 SOHCs (thank God they were easy to do). Tensioners and intake manifold gaskets aside, those were pretty good engines.

[ December 24, 2004, 03:58 AM: Message edited by: punisher ]

 

[metroplex]

When in gear at RPM (mid to high loads), I do not hear anything "abnormal" from the inside of the car other than the exhaust having a bit more growl than normal.

I also recall the tick/clack sound being more "amplified" after the PI intake swap. It could just be resonance through the larger tubes of the PI intake...