wierd noise from engine

[Mark Hutchison]

It seems that whenever it's really cold outside and we don't let the truck warm up to operating temp that we will hear what sounds like a tornado warning, or a siren of some type. It seems to be coming from the engine.



Anyone ever hear of anything like this?



I'd take it to the dealership but it doesn't happen everytime.



Hutch

 

[Larry Michel]

I have a similar noise at idle, off idle it goes away. I have an off-brand, aftermarket intake tube and gauze filter. I blame the intake for my noise-it will humm pretty loudly if conditions are just right.

 

[Todd Z]

If more like a large fan blowing, It could be the fluid in the fan clutch causing the fan to spin. I know on some cold mornings I here that noise... The fan is thermostatically controlled, but when the viscus fluid is too cold even with the clutch released it will still spin for a little bit..

Todd Z

 

[Chris Pesola]

I get this too. I hear it most at right about 40 mph, I'm worried is a transmission or as Todd Z states, maybe the fan clutch fluid is cold. I have an '02 ST with about 80k, I seem to remember it always being there though. Even now, with the MAC intake, no difference.

 

[Mark Hutchison]

I think mine seems to happen around 30MPH, and it goes away once above 40MPH.



When I was out today I noticed the noise to start, so I backed off the accelerator a little and the sound started to dissipate, slowly got back on the gas and it started to come back.



Wierd....



About it being the fan. Are our fans exectric? If so then that would toss that out. But if they are belt driven then this could be it. Guess I should know if my fan is electric or belt driven..



Hutch

 

[Todd Z]

The ST fan is belt driven, No electric fan.... Your fan clutch may be going bad... Or you could have a small vacuum leak...

Todd Z

 

[Fred]

Maybe the alternator. Mine made a noise like that when it was really cold out, and before the engine warmed up. The dealer replaced the alternator, that got rid of the noise in mine.

 

[Alan Peters]

Deal replaced the Alt., water pump, and tensioner on mine and it went away.