Ok so I've been living with this rattle for a while now and I can't take it anymore I really need some help diagnosing it. There are COUNTLESS other threads on TGO with pretty much the same exact description as I'm about to give, but none with a real definite answer. It must be a pretty common problem so I hope this can be the thread to help myself and others truly fix it. There are also two videos that I'm going to post that pretty clearly show you the sound, listen and you can hear it. Here are the symptoms of this rattle:
-At the FRONT of the engine near the pulleys and belt.
-Only when the car is warmed up.
-Only at a certain RPM, about 1000 (auto trans)
-Happens at very slow speeds or while in park just sitting, again about 1000 RPM
-Sounds like a grinding, metal rattle. Quite loud.
What has been done to rule out:
-New water pump. Not that.
-Took off belt and let run, still did it. Not pulleys, alt, or ac.
-Not exhaust, it's tight.
-Not flexplate.
-Not internal, the car runs GREAT.
-Not a heat shield or underneath car.

Only thing that I haven't tried yet is the harmonic balancer, but I'm terrified that isn't it.

Here are the two videos that pretty clearly play the sound:

http://s148.photobucket.com/albums/s...t=SMOV0013.mp4

And here are all the other threads of people with this problem:
https://www.thirdgen.org/forums/tech...hat-noise.html
https://www.thirdgen.org/forums/tech...ng-issues.html
https://www.thirdgen.org/forums/tech...d-1984-v6.html
https://www.thirdgen.org/forums/v6/4...-balancer.html
https://www.thirdgen.org/forums/tech...-2200-rpm.html
https://www.thirdgen.org/forums/tech...tle-noise.html

Thanks for the help

 

Look closely at the timing cover, at the bottom, pass side, the horiz surface between the face with the front seal in it and the oil pan gasket.

What you're looking for is, evidence that the timing chain has been rubbing on the inside of the cover right there; it tends to leave a nice little print on the cover.

If in fact you see that, there is a timing set swap in your immediate future. Do it now, or wait a day or 2 for it to need a tow first.

Often the first sign that the cam sprocket is failing, is that the cover wears completely through right there; and the engine suddenly develops this strange oil leak out of the clear blue.

 

I will definitely look at that, but if it was the timing set wouldn't it happen all the time? The rattle happens intermittently, and only at around 1000RPM

 

Well finally got under the car today. I took off the belt, started her up and got under the car and the main drive pulley was rattling along with the balancer, so I thought that was a good sign even though the balancer did look pretty ok imo. Turned the car off, took off the main drive pulley, pulled the balancer and put the new one on. Put the pulley back on and sure enough it is still doing the noise. I am literally depressed right now, I don't want to sound like a pu$$y, but this is just making me sick. I didn't see any wear on the timing cover, but I think I'm going to try and do a new timing set tomorrow just to rule it out, plus I don't think it's ever been done on the car so why not.

It HAS to be something right there. All the other pulleys are still and that one is rattling and the noise is coming from right there, just what is it? You can see and hear it rattling under there constantly, just very quitely, but it's only when the car is warm and at 1000RPM is when you get the overwhelming rattle that is very loud. Please help me!

 

Anybody......? I'm going to replace the timing set later today and hope that is the cure.

I'm beginning to wonder if it is internal. The main drive pulley is the only one rattling, and I just replaced the balancer so that can't be it. Could it be internal? New engine time? I fear it could be bearings or crankshaft. There is no knock at all. And the car runs great, I just can't figure it out.

 

Was there any update to your problem? Did you ever figure out what it was. Having the same exact issue. Driving me crazy trying to pin point it.

 

Get a long piece of heater hose. Put one end in your ear. With the other end, point it close to where you think the noise is coming from. Point it around and listen for it.

You can also get a long screwdriver or length of hard fuel/brake line. In this case, place the end of the screwdriver/tubing against the surface where you think the noise is coming from and poke around and listen.

Be careful around the belts and pulleys.

 

any update on this?

 

OP hasn't posted anything since 2015 or logged in since 2016 so doubt he'll answer you. Unfortunately another post destined to never be resolved.