Ok so i got off work this morning it was a nice -6 outside and my truck has been running for about 25 min warming up.. I pull out of the work and start to go down the road i get to 55 and expect the truck to go into overdrive.. Waiting waiting and nothing. Then if i keep my foot on the gas at the same position it starts to make a whistle sound.

-No sounding of gears
-No problems with acceleration
-No issuse with any gear but overdrive
-No loud cunks or hard shifting from gear to gear

I stoped the truck turned it off then went ahead and tried again same issue.
Then i tried it in park i sat there and reved the engine to 2500 rmps and after 30 secs of the same constent speed it starts to whistle from somewere in the engine bay. Im thinking it has to be something cloged or some line that is sucking in air.
I can let go of the gas pedal and it goes away but as soon as i leave it at a constent for more then 5 secs it comes back and still no overdrive.. It only does it at a constent acceleration nothing else...

Any help would be great i look for a little bit on this problem but i work midnights and right now am tired as all hell..

 

If I remember correctly our trucks won't shift into od if the temps are that cold. Mine would do that last year on really cold days but its not cold enough here yet to start that yet. as far as the whistle it may be intake noise from running at that rpm. you may not notice it cause it usually goes into OD.

 

^to add to that, take your air box off and make sure that your gasket is still in one piece. if it is then put the box back on and make sure the clamp is on right and tight.

 

No OD or TC lockup until the temp gets to around 150 or so...

 

whistle = air/vac leak. most likely around the air filter.

 

Would love to see that as the problem...

- just did the cap and rotor TPS made sure everything was locked down and tight (filter was changed and its not aftermarket)

- Truck is at running temp (idled for 25 min) and with 13 miles down... More around 180 degrees a little above.

- was thinking it was still intake but it only come on at a consitent speed almost sounds like a turbo but only after rpms are the same for a duration of time. No sound when reving or idle or even threw the power band.

- sound not coming from the top by the intake but more in the front.

- whistle seriously sounds like a turbo spooling almost. Heard it over radio.. Had a leak beforehand and fixed it this sound even louder.

 

fan clutch bad?

the radiator fan clutch is activated by a metal twisted prong in the front, when that gets to a certain temp the fan clutch kicks on. and if its not kicking on, you may be hearing the water pump being overworked.