Loud Humming Noise from 50mph and up.

[gearshift]

I have a 89 Vette, and on occasions while I get on it up an onramp and enter the feeway, at about 55mph I get this serious loud humming noice that seams to come from the front of the car. There is no vibration and if I shift into nuetral, the noise does not go away. If I slow down it does not make a difference either. It eventually goes away after about 10 minutes of driving.

I am thinking it could be the Air Flow Sensor or the LCV joints, but it is so inconsistent, it is hard to tell. Next time this happens, I am going to turn the engine off to see if it is engine related or maybe drive train related.

Has anyone experienced this problem before?

Thanks.

 

[cntrhub]

Is this 10 minutes of driving starting from your place and then the car warms up within 10 minutes of driving? My guess is cold tires? The weather is turning cold and my take 10 minutes to warm the tires up? I doubt it could be the Air Flow Sensor or the LCV joints. Usually these mechanical/electrical noises remain constant.

 

[gearshift]

This loud humming sound was present during the summer months. Would cold tires apply during warm wether? I would say that over the past four months, this has happened five times.

And yes, it did occur within 10 minutes of starting up.

The inconsistency is the big nagging problem. A shop can't figure it out, because this happens so infrequent. BTW it is super loud.

 

[switch]

Fans turning on possibly?

Gordon

 

[cntrhub]

switch (Gordon) came up with a good point. Could be a locked fan clutch you might be hearing? But now that I think about what you said...."There is no vibration and if I shift into nuetral, the noise does not go away." ...... it couldn't be the fan clutch. Selecting neutral would quiet the fan down. UGH!!
We'll nail this thing yet :bang ....hang in there.

 

[Robertwav1]

Maybe a front wheel bearing. I had a firebird a long time ago and would get that humming sound at certain speeds. Turned out to be a wheel bearing heating up and cooling down. Just a thought!