Random Clattering Noise

[CaptainComet]

Hi all,

I have a 98 Sport with 4.0 SOHC motor. It has 91K miles now and has just developed an odd random clattering noise. I feel like I should already know what this noise is ... seems old school, like I had a 70s-era car that did the same thing.

It does not vary with engine speed, and does not change if the A/C is turned on or off. Cold or warmed up. no difference.

You can hear it better if you are under the radiator than above the motor.

It does not seem to be coming from PS, AC, idler pulleys, valve covers, or engine itself. I was using a large dowel rod as a stethescope to try to pinpoint this. Could not get to the water pump due to the belt.

The fan does not seem to be loose or wobbly. Do fan clutches get noisy as they age?

How about AC clutches?

A bit stumped here .... seems to be running fine. I would think that increased engine speed would increase it or make it go away, but no real change.

 

[Abbondanza]

I had a similar noise, sounded like a small rock rattling around in a tin can.

In my case, it turned out to be the tensioner pulley.

Initially I couldn't tell it was the pulley making the noise (thought it may be the alternator), but replaced it because like you I couldn't pinpoint the source and they pulley was a relatively cheap fix attempt.

If you remove the belt and rotate the pulley by hand, you can get an idea of what the bearing's condition is. On mine, the whole unit that held the pulley was started to come apart, causing an off rotation angle, which was probably why the bearings went.

 

[Blue91Ex]

also if it doesnt sound like its coming from the engine, check out your U-joints, my moms ram has bad u joint and it clatters like that.

 

[98Explrrrrer]

Had a similar noise turned out to be the connector on my transmission pressure line coming loose found out when a bunch of fluid was lost all over the ground .

Check the lines from under the vehicle the come off the rad on the drivers side .

my truck is in getting fixed or I would send you a picture.

 

[CaptainComet]

the tensioner pulley makes sense ... I'll pop the belt off and check all the accessories without have the belt keeping everything tight.

This noise is while the truck is sitting still idling and while you rev the engine without it moving, so that eliminates u-joints ... although those are on my list to replace ... trying to track down a 70 mph shake, and they are suspects.

No leaks. But thanks for the suggestions.

 

[swshawaii]

Harmonic balancer?
http://www.explorerforum.com/forums/showthread.php?t=302068

 

[delexploder]

I hope its your tensioner but sounds like timing chain guides or tensioners

 

[CaptainComet]

Thanks for the ideas, guys ...

I will be looking closely at the balancer. Had one seperate on my last daily driver (non-Ford) and eat a bunch of stuff on it's way out the door. Stupid thing still ran really OK, even though it chewed up a plastic timing belt cover.

"Gee, what's that noise?"....

No belt squeal, so hoping that is OK.


Timing belt tensioners ... that is the first place I was listening and things sound fairly quiet there.

The noise sounds like a ring of keys in a coffee can, and pretty much out front and in the open.... not muffled.