signs of bad crankshaft pulley?

07 4.0 191k
I’ve been trying to narrow down which of the two is making this god awful noise I’ve narrowed it down to either the water pump or crankshaft pulley, no leaking from the water pump, no overheating either. Really makes the noise after accelerating. When sitting and idling it will continue for maybe a minute and then stop

 

Maybe remove the drive belt. Doing this will keep the water pump from turning.
A short trip with a cool engine won’t hurt. Like around the block. Obviously you want to keep watch on the temperature. But this is a common practice to diagnose external engine sounds.

The crank pulley is solid. It has no rollers. It’s mounted firm to the crank.
I would not think it would make the noise you are describing.

 

High pitched whine? Idlers are very very very common on the 4.0

 

https://youtu.be/DQbLXPMDh94

i have replaced the fanclutch, all 3 idler pulleys, the tensioner pulley and the belt. I have a small power steering pump leak but other then that no fluids leaking

 

Go buy a cheap mechanic stethoscope from HF to help pinpoint the noise. You have to test and listen to all components that are associated with the belt. (tensioner, a/c, PS, alternator, etc). Not the most reliable method but you can also try replicating the noise while squirting water to each pulley to see if the noise changes.

 

signs of a bad crank pulley?
I'd say the fact that you even have one at all.
Fluidampr is better.

or not waste time (money) trying to isolate a water pump instead of just replacing it regardless like it should be at 100k

 

Did you flex the water pump pulley around when you had the belt off? Any play?

The harmonic balancer can separate at the rubber between the inner/outer halves. Look at it closely and see if it's wobbling with engine running

A stethoscope is your friend here, they aren't expensive

Running it briefly without the belt like Tn mentioned would help rule out an internal /mechanical problem

 

A faulty crankshaft/harmonic balancer pulley is rare on tacomas but you will have obvious vibes if it's the culprit. Get a buddy/gf to replicate the noise while you listen to each component with a stethoscope.

 

In mine the rubber degraded, the wobble caused the belt to jump behind the pulley and take out the front Jain engine seal, dump all the oil out of the motor

 

How long did you noticed the vibes before that occur?

 

I had no vibes. However I was chasing an annoying belt/pulley sound for a LONG time. I replaced literally everything including the water pump.

turns out it was the tensioner assembly. Use a stethescope and also take a video with the skid plate off.

 

That's pretty unusual to not experience any vibes, especially at higher rpms when the rubber began deteriorating.

 

I've seen balancers fail on smaller cars like subarus and such and they've never had any vibes. The belts get dragged around on the pulleys and they squeak and get shredded

I agree, you'd expect vibes to be present but it doesn't always happen

 

Exactly what happened. Belt jumped a few times but visibly the front of the crank pulley looked fine, then it shredded the belt and threw it completely

 

@Airdog

 

i took off the belt again and ran it for awhile and no noise, put it back on and let it just sit and idle for maybe 4-5 minutes no noise, bumped the accelerator a few times nothing, then out of now where after bumping the accelerator again there it was, I’m getting out of the Army and i head back home next week so I’ve been pretty busy but tommarow ill goto HF and get that stethscope and listen its definitely from the water pump/crank pulley area, crank pulley seems to be fine doesn’t seem to wobble when it’s making the sound or not.

 

You've checked the oil right

 

manual or automatic? That noise posted does not sound like belt squeal.

 

One ear for the stethoscope. It will be very loud when you find it.

Seriously. Don't play doctor when looking for a squeaky bearing. One ear and it doesn't need to be jammed in. You'll hear the bad one noooooooo problem.

 

What's the part number for that balancer?