Help Diagnose - Front End Noise

2000 Tacoma 4x4 2.7L 3RZFE

200,000 miles

Front end noise / rattle/ knock. Been going on for at least 5,000 miles with no significant change. Can usually only hear it at idle and when driving it is not audible (but likely still happening).

Harmonic balancer has slight wobble to it, but otherwise the motor is in great shape. I can feel a bit of vibration on the intake plenum that corresponds to the noise.

 

Bump - any ideas

The noise is that hollow rattle that seems to come and go

 

Thanks - it definitely has a little wobble but nothing crazy.

I originally thought it was a belt pulley with a bad bearing so i replaced one of the tensioner pulleys that was bad, but noise is still there.

 

Subbed . I have 2000 4 cyl prerunner that is a little louder than I would like after a head replacement.

 

same noise tho? Did you replace timing chain/tensioner as well with head?

 

Yes I replace the tensioner when I did the head. I wouldn't say it's the same but the trucks are not side by side to listen too.

 

Heave you tried using a stethoscope (mechanics) or a long screw driver to your ear to isolate where it's coming from?

 

Just listened to your video, I know I've heard something like that before on a vehicle I worked on/repaired. But must've been a while ago. I can't put my finger on it. Damn this is driving me nuts. I know exactly the noise you're talking about though. It'll come to me. Give me a bit.

 

pull the belt/belts see what it does? go away?,,, mine has 3 belts but it's a 95 2.7. if it has more than one, pull one at a time between starting.

 

If I noticed my crankshaft belt pulley wobbling slightly, I'd fix it as soon as I could. I think that eventually the wobble will worsen to a point where it will eat away at the woodruff key that fixes the position of the pulley on the crankshaft and cause major crankshaft problems.

Better to spend a few hours and a few bucks on a new pulley now than to replace the crankshaft later, don't you think?

 

noise was coming from Alternator. what a relief.

Water pump also had some play in its bearing so im putting a new one in too.