Whining noise from engine

[Ivan90]

I've got a whining noise coming from the engine when at idle. The whining stops when I rev the engine, then returns when the engine returns to idle. The whining occurs both in gear and neutral.

I removed the serpentine belt - and the whining noise is still there. I believe that rules out the alternator, a/c compressor, water pump, power steering pump, and tensioner pulley.

I bought a mechanics stethoscope, but still can't identify where it's coming from. I believe it is internal in the engine. All fluids are good.

Any ideas what's causing it... and how to diagnose it? Thank You!

 

[Erik the Awful]

I can't hear the noise from here, so here's my best guess. Check your distributor cap, and if that's all good, pull off your bellhousing cover and check all the torque converter bolts.

 

[Schurkey]

Whining? Maybe whistling?

Vacuum leak at split vacuum hose, or deteriorated gasket?

 

[Ivan90]

Whining? Maybe whistling?

Vacuum leak at split vacuum hose, or deteriorated gasket?

Schurkey - you were correct!
Ends up this was an easy fix.
Years ago that plastic tube that connects the PCV valve to the base of TBI, got brittle and broke. Its a vacuum line. I replaced it with a rubber fuel line. All worked well for years, but eventually the rubber line softened up enough and collapsed in on itself. It was making a squealing noise (pretty loud), similar to stretching the outlet of a balloon as a kid. I replaced that fuel line with a stiffer line that was reinforced. The whining/whistling is gone. Of all the problems that could have been - I'm happy this was a quick/easy/cheap fix.
Thanks for the note above - you were right.

 

[Ivan90]

I just checked - that replacement tube (Dorman 46001) was only $4.28 at amazon, so I ordered the correct replacement.

 

[GoToGuy]

Ya gotta use the correct material of hose. They will melt or swell, or burst, just a bad day. Whatever you're changing make sure it's rated for what your changing / replacing.

 

[PlayingWithTBI]

I just checked - that replacement tube (Dorman 46001) was only $4.28 at amazon, so I ordered the correct replacement.

I use that one too. In this climate it lasts maybe a year or two before the rubber hose at the TB dries up and splits.

 

[someotherguy]

I just checked - that replacement tube (Dorman 46001) was only $4.28 at amazon, so I ordered the correct replacement.

You'll likely find the rubber elbows on the Dorman part will fail quicker than the fuel line you originally used. This is a nearly worthless item from them.

Richard