Wheezing/screech/whistle sound on startup

[simple]

I've been noticing that when my 4Runner starts up, it gets this pretty bad like scream type sound to it. Its almost like an engine screech...it lasts for a few minutes, and then goes away. Any ideas on what this could be?

I have an 04 v6 42250mi

 

[madmmac]

Probably a belt. Pick up some belt dressing spray at you local auto parts store and give them a spray.

If that does not cure it, you are probably looking at a bearing somewhere(alt/power steering/A/C) and some $$$'s.

 

[simple]

Ah schnap. Will definitely head to autozone after work today! Thanks for the reply.

 

[simple]

It worked! But as I was letting the engine run as the belt was distributing the dressing spray, I noticed my engine had a knock. I had driven approx 45mins in town, before putting the spray in 70degree weather so the engine was warm so I don't think it was piston slap. I use 87...but only from Shell and sometimes cheveron!

 

[Spider5]

Because of the slipping belt the engine management computers might have adjusted the timing to compensate for it. Try removing the battery cable for a couple of minutes to reset the computers

 

[96dcmss]

The noisey belt would have had nothing to do with any timing or other engine management. The ECM has no way of knowing what is wrong with the serpentine belt.

Also, belt dressings are usually for older style drive belts, not serpentine belts. Fix the root cause, which most likely is a bad belt, and maybe a tensioner.

 

[simple]

The noise came back. I believe I will have to change the serpentine belt. But I'm a little confused. From the research I've done, the Serpentine belt is whats in front of the engine (what I sprayed), right behind the bigass fan at the very front of the hood. Correct? That is different from the timing chain, which is in my v6, vs. the v8 which has a timing belt. Am I still tracking? What is the difference between belt and chain. Belt should be changed at 90k, but when should the chain be changed.

Also, do I need to change the water pump too, if I change the serpentine belt and tensioner? And is this a stealership type deal... or is this a DIY type thing?

 

[Spider5]

The noise came back. I believe I will have to change the serpentine belt. But I'm a little confused. From the research I've done, the Serpentine belt is whats in front of the engine (what I sprayed), right behind the bigass fan at the very front of the hood. Correct? That is different from the timing chain, which is in my v6, vs. the v8 which has a timing belt. Am I still tracking? What is the difference between belt and chain. Belt should be changed at 90k, but when should the chain be changed.

Also, do I need to change the water pump too, if I change the serpentine belt and tensioner? And is this a stealership type deal... or is this a DIY type thing?

The timing belt is inside the engine. The spay is only a short term fix to prolong changing out the belt if one can't be found right away like on a trip.

 

[Methodical]

while the belt is off, check all the rolling surfaces for bearing play. They should all be very rigid and turn twist and turn at all, just rotate. You'll know if something feels weird because it'll feel way loose compared to the others. Typically the bearings that go are the idlers, the ones that aren't connected to anything but only serve belt routing purposes.