Engine Whine

I've been hearing a loud whining noise (I'll call it) when my truck idles in the morning when it's cold out. It is by no means a consistent noise or pattern but this is the typical scenario:

* start truck cold in am, say temp is about 15F or colder
* truck starts normal, fan blows lot's of air for 30 seconds, then fan noise falls off
* truck idles for about 3 minutes at higher idle without the whine
* another couple of minutes and idle drops to about 900-1,000rpms

Then the whine starts. It comes and goes but when it's there, its LOUD. If I barely blip the throttle it disappears. When I pull out of the driveway, it disappears. When I drive to work, no noise. Once the engine is good and warm, no noise. Just when I let it warm up and don't touch the throttle.

I've popped my head under the hood when it's whining loudly and I cannot tell where it's coming from- crazy considering how loud it is. It's not a belt- it's not a screech. I am guessing it's a bearing somewhere on the belt drive, either an idler pulley, or maybe PS pump or Alt. I have not turned the wheel when it's whining to see if it stops or changes pitch- I'll do that next. A stethoscope may help pinpoint it. I read the idler pulley bearing replacement post and could try that- easy enough fix. I took a vid this morning and captured the noise perfectly- you can hear it coming and going. I do have a TRD s/c and would be bummed if it's the snout. My truck has 66k on it.

the vid is wrong format and too large. I'll work on a solution and post it up

 

Ok, I converted the vid into a mp3- should get the point across. You can hear the whine coming and going. Thoughts?

 

Sounds like a belt pulley bearing going bad.

 

Yep. Time for some new idler pulleys.

 

Yeah, that's kinda what I figured. But, with the 4.0 supercharger, I have about 4 more idlers and another tensioner. That's a lot of possible bearings to be going. Maybe a stethoscope will help me pinpoint the culprit. If I figure it out, I'll post it here. If any s/c guys can chime in on likely places to look...

 

With all that going on I would def get a stethoscope.

 

odd how it comes and goes........... does it change when u turn on the a/c or turn the wheels at all?

no clue if this helps diagnose, but figure its worth a try.

how many miles are on the supercharger, and HONESTLY, how hard are you on the truck?

 

is there a way to put the stock belt on the truck and bypass the blower pulley?
if this is doable and the noise goes away, well......... thats not good.

if it stays the same, than maybe we can rule out the blower?

 

The engine has 2 belts now- stock and the dedicated s/c. I'll start with a stethoscope and see where that get's me. As far as being hard on my truck, it's super fun to drive with all the engine and suspension mods I've done. It's not really anything like a stock truck. It corners really well for a truck and drifts smoothly and confidently. I drive it pretty hard sometimes

 

If you remove the belts and spin all the pulleys by hand (the crankshaft might be tough, and probably not necessary ), you will almost certainly turn up the rough bearing(s)

 

Somewhere o er on Eaton's site, they give avg service mileage..... Under tougher conditions like hauling, racing etc, there's provisions for a shorter maintenance schedule on the nosecone oil.


May not be ur problem, but its not gunna hurt either.

 

I stuck a screwdriver to the snout and 2 idlers this morning and don't believe the whine is coming from them. I thought it seemed louder near the alternator. I'll get after it Saturday morning, early when it's cold outside. This has been going on all last winter as well- only when it's cold though.

My charger has about 66k on it. I was planning a snout rebuild when I pull off the s/c to machine clearance for a smaller 2.7" pulley

 

That is good advice- thanks. Earnest troubleshooting Saturday morning. I'll post what I find. Thanks guys..

 

goin big are we?

or shall we say small

either way,

 

I've been wanting to install the 2.7 + 7th inj for a while, and finish my exhaust out. All that stuff is pretty $$ so I've been waiting..

I guess I'm justifying it somewhat by saying my snout may need a service, ha hah but I don't think it does. It just never ends does it...the need to mod your truck?

 

I have a 2008 TRD and the same issue. The noise is not consistent and more often when its cold. I am interested to find out what you discover!