Engine whine

[Pomorza]

Hey mates

This evening my Z starting making an interesting whining noise. It goes up and down with engine speed and just seemed to appear though it could have been happening for a bit - I have a bit a loudish exhaust. It doens't matter if the clutch is depressed or not. Question I have is this, other then the alternator and waterpump is there anything mechancial that could make a whinning noise? I'm going to yank the belt of tomorrow and run it with the belt off and see if it's still there but would like your guys opinion.

Thanks

Jan

[siteunseen]

If it's coming from the front of the motor I think you're on the right track. Do you have A/C? You could also pull the cam cover and check the tightness of the timing chain. Good luck!

[240260280z]

Timing chain can make a noise up front

[Pomorza]

Thanks guys, The sound "seems" to be coming from the front area but I can't be 100% positive, as well everything is metal and tends to echo.

Blue: Wouldn't timing chain noise be half the speed of the engine since the cam moves half as fast?

Jan

[Willoughby Z]

Old shade tree trick: long screwdriver used like a stethoscope- steel tip in contact with any item/area to be examined and the plastic handle against your ear.

[240260280z]

The chain is connected to the crank as well so it will couple noise from both the crank and the cam but most noise will be from the chain scrapping along the chain guides.

The cam sprocket is bigger so it will turn slower than the crank sprocket....1/2 the speed as you said.

[Pomorza]

Update:

Well I came home from work all ready to disassemble the Z. Turned car on, no noise. Waited for said Z to warm up to operating temperature - which took a while - still no noise. Let run at operating temp for ten minutes while attempting to find said noise, nothing. The only things I hear is the cam, exhaust, the intake (which sounds like a vacuum cleaner sucking) and my injectors ticking. No more whine, maybe she was just moody.

Jan

[Lazeum]

My alternator/fan belt was undersized vs. my pulleys.

My engine was not stock, as a result, crank pulley needed a 10mm wide belt while alternator & fan needed 13mm. 10mm belt fit but it hit the bottom of the groove instead of contacting the pulleys on the sides. As a result, it was from time to time slipping.

I've changed damper with a later unit with 13mm wide which allows me to use now 13mm belt, it does not slip anymore.

[FastWoman]

Jan, whenever I've heard an engine whine, I could generally pull off the accessory belt(s) and find a loose accessory bearing just by turning the individual components by hand. The offending bearing would feel rough and loose.

I read/hear very often about the long screwdriver trick, but the neurobiologist in me tends to think about this poor guy: Phineas Gage - Wikipedia, the free encyclopedia. I'd strongly recommend one of these instead of a long screwdriver: Mechanic's Stethoscope. It's only $5, which is a lot cheaper/better than a screwdriver launched through your skull. And speaking from personal experience, my little $5 stethoscope is surprisingly good -- a lot better than a screwdriver could ever be.

Edited November 12, 2013 by FastWoman

[jwilliams905]

Hmm. . . I believe the fan clutch could make a whining sound if it went bad. I know the whining sound from a limited-slip differential comes from clutches and plates slipping, so I assume it could possibly be that. Not sure if a tiny clutch could make a dominant sound, but if a cricket can be so loud, you never know.

[txvepr]

Harbor Freight, this:Mechanic's Stethoscope

Your Friend.