Rattle noise

[Spitfire1975]

sounds like a quiet exhaust heat shield rattle, but appears to be coming from the passenger side of the engine compartment. Can't really narrow it down. It is not an intermittent noise and doesn't seem to change with engine RPM (you just can't hear it as well when the engine revs and gets louder). Any ideas? Something simple like a heat shield? or something more sinister, like bearings, rods, etc...

 

[Spitfire1975]

the transmission is pretty well shot in this truck as well (5 spd). Maybe something in the clutch/pressure plate area that is worn out and loose? It definitely seems to be coming from the lower regions of the engine compartment.

 

[Spitfire1975]

Engine vacuum is perfect to specs. compression was a little ominous (BUT I tested it when it was dead cold and had run for several days). Numbers were as follows:

1 - 150
2 - 180
3 - 170
4 - 160
5 - 170
6 - 140

Once again. I tested when it was cold (and I did floor the gas pedal). It isn't burning oil and seems to not be losing any water. No air bubbles in the coolant or puddles under the truck either.

 

[low_five]

catalyltic convertor. mines doing about the same thing. if thats not it, it might be the throwout bearing.

 

[Spitfire1975]

not coming from the cats.... Throwout bearing would make more sense, those will rattle instead of making the typical grinding noise?

 

[low_five]

ive heard em squeak rattle and grind. try pressing the clutch in and see if it goes away.

 

[Spitfire1975]

Nope. Clutch out....grinding noise (bearing rub more than a grind. Same noise my 86 BII makes). Clutch in, no noise other the the rattle.

 

[Spitfire1975]

The input shaft bearings and main shaft (I think it is the main shaft) bearings in this tranny are toast. It is the loudest tranny I have ever heard. Changed the tranny fluid and it looked like well used motor oil.

 

[Spitfire1975]

Ok. spent some quality time with a metal rod (stethoscope). It is the alternator making the noise.

I hate tracking down weird noises. They seem to travel everywhere.

At least it wasn't something serious.

 

[kimcrwbr1]

Mine had that rattle until I had a muffler put on it. The muffeler was full of cat parts and the cat had some also the muffeler guy shook out he cat put on the muffler and the rattle is no longer. The front half of the cat was still good

 

[96Greenster]

Aint it funny how u think its something and ends up being something not even close...lol

 

[Spitfire1975]

Aint it funny how u think its something and ends up being something not even close...lol

I should have spent more time searching before posting.

 

[kimcrwbr1]

I hope thats It for you i tseemed that every time i got under it it stopped ratteling or like it was from the tranny but the cat was right there maybe try pushing up on the cat with a board or somthing and see if it goes away.

 

[Spitfire1975]

Cat seems quiet on this truck. When I was hearing this "rattle" as I like to call it, I was worried about something internally wrong with the engine. Using the metal rod to "listen" through, the noise is loudest when I touch it to the alternator, can't hear much at all when placed anywhere else.