Hello,

I have 95 z28. Lately i have been having a high pitched whine sound that comes from the engine bay. It stays on for about 2 minutes or so after i start it and drive off itll go away. I was told it could possiblt be an air pump. I cant even tell what side it is coming from. any ideas?

 

air pump is electric so try unplugging it. it would help greatly if you could post a recording of it. alternator, power steering pump, belt tensioner come to mind with the alternator being my first suspect.

 

Alright I will work on that today and post a video link. Would there be any issues if I unplug the air pump ?

 

How is your belt tensioner's tension -- has it ever been replaced? Then check any of the other pulleys and belt-powered accessories for bad bearings, etc., like Craby mentioned.

Air pump is emissions related, so unplugging it to check a noise should not be an issue temporarily, longer term it may throw a code...

 

actually i dont think it will throw a code if its unplugged. in any case it won't harm anything.

 

Sorry for the late response it has been raining alot down here. I noticed the power steering pulley is wobbling, i am going to chage that this weekend. The air intake hose has a some tears near the T/B. I am changing that too. Here is a video. Let me know what you think

 

What I would do, Remove drive belt. Does the sound go away? If yes if it does I would reinstall it and us a can of WD40 with the long tip on it. First spray the belt V notch sections with just a touch. Did the sound change? If so then it could be a bad belt of an alignment issue. If not then spray around the tensioner and so on. Also an automotive stethoscope are super cheap harbor freight and can help a lot, even a broom handle used like a stethoscope works well. Heck I think there is an app for that
If the car still makes the noise with the belt off report back here or take to a mechanic that knows LT1s (you may have to ask around) it could be indicating problems in the waterpump or waterpump drive system and could lead to a major issue.
Just a FYI there is a chance that the power steering pump has always wobbled. The pulley itself is just a stamping and even new they can wobble. Now if the “wobble” is not coming from the pulley it is being caused by the bearings in the pump then is could be the cause of your issue.
Any air leaks on the engine side of the MAF will affect the way the motor runs and should be fixed ASAP.

 

sounds like a very bad pulley to me but make sure. Get a stethoscope and find out where the sound is coming from.

 

like said take the belt off and see if the noise goes away. water pump is driven by the cam so no worries with overheating or harming anything. make sure you get the belt away from the crankshaft as it will be spinning and a belt wrapped around it could do some damage.

 

the alternator had a pretty nasty pitch when i removed it. I ordered a new one and a new belt. I will update once all that stuff comes in