'95 CSC - LQ1 odd noise

[06goat75]

Did a bunch of work to the LQ1 the past week or so, changed the lower intake manifolds, temp fixed the distributor plug oil leak, new oil distribution cover gasket, thermostat, PCV valve, and new plugs.  Changed the oil and doing a coolant flush.  Still some more stuff to do though, especially on the inside.  

But, started it up and seems to run decent, idles just below 1000 RPM.    Revs fine.  Gonna let it sit over night and see how she runs in the morning.

Seems to be some sort of whining noise coming from the timing belt/power steering pump/water pump general area.  Goes away when you rev it to say 2500 or so RPM, and comes back when it idles down.  

It has roughly 82K on it.  Not sure if the timing belt has ever been changed, so that's on the list.  No codes.  

I'll be honest, haven't done a lot of troubleshooting yet, but figure I'd drop a quick question on here to see if anyone has any thoughts.  I know it isn't much to go on.  I took a video, but I'm not good at the video thing, so not sure if it is worthwhile or not.

No idea if this works or not, but you can hear the sound go away around the 18 second mark.

Have a new belt to go on it, just haven't gotten to it yet.  

 

Edited January 31, 2020 by 06goat75

[57lxi]

This might be a stretch but I had a noise that mimicked a power steering whine on my lq1 CSC. Fluid was good. Would go away when I reved it. Followed noise. Found hose from PCV valve to upper manifold would partially collapse under idle vacuum causing PCV valve to “chatter. Hose was OE and really squishy. Replaced hose and valve and noise went away. BTW, PCV valve was kinda a bugger to get to.

[Schurkey]

On 1/30/2020 at 6:28 PM, 06goat75 said:

idles just below 1000 RPM.

Seems high.  Needs time to re-learn proper idle speed???

What is the scan tool saying about actual idle speed vs. commanded idle speed?  IAC working?

[06goat75]

On 2/2/2020 at 9:24 AM, 57lxi said:

This might be a stretch but I had a noise that mimicked a power steering whine on my lq1 CSC. Fluid was good. Would go away when I reved it. Followed noise. Found hose from PCV valve to upper manifold would partially collapse under idle vacuum causing PCV valve to “chatter. Hose was OE and really squishy. Replaced hose and valve and noise went away. BTW, PCV valve was kinda a bugger to get to.

I think the power steering pump is going out, as it makes noise when I turn the wheel, driving it up and down the driveway.

 

However, I looked at the hose from the PCV to the intake, and it was doing the same thing, collapsing under vacuum, so it needs to be changed too.  Thanks for the insight!