4.7 Engine whine?

Hey everyone! New to the forum but I have been in ih8mud for a bit. I recently acquired a new to me 2006 double cab with 194k miles. When I purchased it I noticed a slight whine when accelerating hard. Had a shop take care of timing belt as pm and the noise seemed to be reduced. This morning I changed spark plugs (Denso IK20) and air filter (wix) and the whine seems to be worse. I can hear it a little while driving, but its very noticeable with rpm while in park. Peaks around 2500 rpm it seems. Any ideas? Also has a new serpentine belt and pulleys .

 

Belt tensioner is my guess...or a idler pully bearing is about to seize up...if you can, remove your serp belt and see if your pulleys spin easily without a lot of wiggle...I'm confident you'll find the culprit...YouTube the belt removal process and it's 100% fixable yourself, if you can...

 

Anything with a bearing is a culprit. Alternator. AC compressor. Tensioners, even recently replaced ones. Power steering pump. Get an automotive stethoscope and use it to narrow down the source of the whine. Power steering is a common source of whine if it seems related to steering input and RPM.

 

Suggestion for you.

1. Take a video so we can hear it. (upload to www.imgur.com and post a link to it here)
2. Shut off the truck.
3. Remove the serpentine belt and start the truck again.
4. Is the sound still there?

If the answer to #4 is "no", then you know the issue is somewhere on your accessory belt, i.e. a pulley you haven't changed. My money is going to be on the pulley for the fan bracket, I would almost bet money on that if you haven't changed the bracket yet.

Most of our colletive knowledge we've documented is in here, in the event you want to learn more about your truck: https://www.tundras.com/threads/so-you-wanna-buy-just-bought-a-1st-gen-tundra-eh.115928/

Especially if you're in the rust belt, you'll want to give it a read.

 

Update: removed the belt and whine is still present. Attached is a video of the noise. Also unrelated to steering input. https://imgur.com/a/Hq3YLtc

 

Ok, so the next question is: What rotational masses still exist when the serpentine belt is off and the truck is stationary?

 

Only thing i can figure is crank pulley and torque converter? That whine isnt normal for these right? I want to make sure im not imagining things or on a wild goose chase haha

 

I haven't heard that much whine, no. I don't see how the crnak pulley/harmonic balancer could make that noise.

Actually, have you sprayed brake cleaner around the edges of the the intake to see if idle surges? It's entirely possible the intake has a gasket leak or something. I'd expect it could cause a whistle.

 

Just checked a minute ago. Sprayed the area with throttle body cleaner and listened for a rpm change. No change present. I then opened the airbox and did the same thing (i just replaced the air filter this morning) and it doesnt seem to have changed

 

How about the SAIS pumps?

 

How would one check sais? No CEL or anything

 

It lives under the intake. Automotive stethoscope……

 

Atf full? That completely sounds like a serp belt driven problem. But maybe the trans pump is starving?

 

Ill have to report back on that. Running out of daylight. Just ordered fluid to do a change anyways

 

Dang, if I didn't know your belt was off, I'd guess something serpentine driven.

Did they change the idler and tensioner for the timing belt? Really sounds closely tied to rpm..

 

This. I had a 2001 Isuzu Trooper that made an identical noise. It turned out to be a spacer that was missing in the TC/flex plate area. It eventually took out the transmission. Different beasts, I know. But, damn, I recognize that whine.

 

not that far of a stretch.

 

Only runs <60 secs from cold start though. Shouldn’t happen during acceleration.

 

Ill start with drain and refill on the transmission. Mine is the 5 speed (A750F?) so im not super concerned. Picking up WS fluid from the stealership tomorrow.

 

Able to hear the video this morning (was on a plane yesterday and it wouldn't load). That sounds like a tight bearing. Like when you overtighten your front hubs and compress the bearing type whirring noise vs a whining. I would be suspicious of what's going on under the timing cover. Before you start doing random interventions and throwing money at it, you really need to pinpoint the location that the noise is coming from.

 

It absolutely sounds like a bearing to me.

 

Update: checked and changed atf with no change. OEM WS fluid from dealer was used. Followed a video from here on how to change/check correctly. Old fluid didnt smell burnt and had no metal or anything in it.
Did some more digging and considering bypassing sais? The only thing making me question sais is that the noise doesnt go away. Im seeing that typically sais noises go away after 20-30 seconds. Is this always the case? I can hear the noise when engine is cold and warm. Regardless of time running.

 

It’s not SAI issue. The pump only runs first 30sec of a cold start if ambient temp is within a certain range. Don’t parts-cannon it. Stethoscope. Track it down.

 

This.