Timing Belt Area Noise

[engiekev]

I've been troubleshooting a loud whining noise coming from the timing belt area, and I'm looking for some advice from those with a similar experience.

The noise is constant, whining and high pitched. Increases in pitch with RPM, audible at idle. I've tried using a stethoscope to isolate and haven't had any smoking guns yet. The timing belt appears to be in good shape.

So far, I have attempted, with no change in the noise:

-Removing timing belt plastic covers
-Removing waterpump/alternator/PS pulleys and belts
-Replacing timing belt tensioner and re-timing
-Replacing timing belt tensioner and idler pulley and re-timing

Would the oil pump be the next thing to check? The drive pump sprocket nut does not appear to be loose.

I'll post a video shortly.

 

[tektic]

It's going to be the bearings. Could be the water pump, a/c, alternator or idler pulleys. Get yourself a stethoscope to help determine which it is.

 

[engiekev]

Still makes the noise with water pump, a/c, alternator disconnected.

Idler and tensioner pulleys are both brand new, makes the same noise as it did with the old ones, which were in good shape.

Will try again with a stethoscope and get a video of the noise.

 

[thomcasey]

I assume your BS's are deleted? If not, could be the bearings for them. If they are, I would look at the oil pump. I would hope you used the Mitsu kit for the BS delete for the lower BS.

 

[transparentdsm]

oil pump..

 

[engiekev]

Quoting thomcasey:
I assume your BS's are deleted? If not, could be the bearings for them. If they are, I would look at the oil pump. I would hope you used the Mitsu kit for the BS delete for the lower BS.



They appear to be deleted, though I have no idea if the previous owner did it correctly. Looks like they left the front shaft in, but no way to tell if they used the stubby shaft.

Will likely be pulling the front case to inspect.

Got a good video of it, working on getting it posted.

 

[engiekev]

Video up here:

https://www.youtube.com/watch?edit=vd&v=zQhtyVCcU6A

 

[engiekev]

Another question, I've never heard 90 straight-cut gears like that, could they just be a noisy set?

 

[thomcasey]

Sounds like either they left the rear shaft in and the bearings are getting ready to seize (my 2nd oldest son's talon had the rear BS bearing going out, sounded the same) or the oil pump is very worn. Either way, there should be sparkles in the oil.

Also a possibility, how is the timing belt tension? A belt that is too tight can sound like this.

Quoting engiekev:
Video up here:

https://www.youtube.com/watch?edit=vd&v=zQhtyVCcU6A

 

[engiekev]

No visible shavings or flake in the oil.

I've re-timed it 3 times now, using the special tool and beam torque wrench. Worth a shot going a little looser, I'll give that a go and see if it changes.

 

[tektic]

Sorry I didn't read the whole post before my response. The steathasope may still help but I would pull and inspect the pump.

 

[strokin4dr]

Before going through the trouble of loosening it, check the hydraulic tensioner to see if the tension is set correctly (measure the piston protrusion). No sense in risking some bent valves with a loose timing belt just to see what happens.
My guess is on point with Thom. Oil pump or balance shaft bearing. Good luck
-Ryan

Quoting engiekev:
No visible shavings or flake in the oil.

I've re-timed it 3 times now, using the special tool and beam torque wrench. Worth a shot going a little looser, I'll give that a go and see if it changes.

 

[engiekev]

Following up on this:

It was the oil pump. The engine was not put together properly, they had cut the balance shafts instead of using stubby shafts, and the driven gear was eating into the pump housing. Threw a new pump on it, re-timed, and the noise is 100% gone.

Here is a follow up video, with some gratuitous revving for good measure:
#367/1000 Post Surgery & Exhaust testing

 

[mitsuturbo]

Cutting the BS isn't a problem, provided it was done right and the hole was properly plugged in the shaft.

 

[engiekev]

It was not properly done. I don't know the root cause of why the pump started to eat itself, supposedly the motor was "rebuilt". The noise got consistently worse as I drove it. The bearings on the bottom end looked fine, so its not an oil starvation or pressure issue.

Point of this post: do not trust any regular machinist without 4g63 experience to build your motor.

Pictures for your enjoyment