Squealing Belt at Startup

[honschoppt1]

Any help would be greatly appreciated!!!!

Since I've owned my QX4 (about 9 months), every time I go to (cold) start the car there is a really loud squeal. It used to only last 4 or 5 seconds but now it's almost 20 seconds long. It also starts to squeal when I come to a stop or slow down dramatically after going about 45-60 m.p.h. When the car is warm there is usually no squeal upon startup, only very rarely. Is this something I can fix myself? Do the belts need tightened or do I need a new tensioner(s)? Thanks for your help!

[attofarad]

Yes, you probably need to adjust the tension. You should also take a look at the belts and see that they don't have obvious wear, cracking, et cetera -- if they do, replace them.

If you download the factory service manual, the procedure is described on page 13 (at least on my 2001 QX4 one) of the MA (Maintenance) section. If I recall correctly, you will have to remove the plastic belly pan -- same one you remove for changing the oil filter -- to get to the adjustment point.

Once you fix it, check the tension every couple of years and adjust as necessary.

[yeldogt]

This is not an uncommon problem.

The truck uses the older style conventional "V" belts -- not a serpentine with tensioner. The belts need to be tensioned manually -- and need to be on the tight side. Your may need to be tightened or replaced.

I would recommend that you get the exact belt from Nissan. If you order them online they are no more expensive and they will fit without any issues. I never had any issue with the 02 that I bought new -- both of the used ones I bought had to have the belts changed due to squeaking -- both had aftermarket belts installed ... switching them out solved the problem.

The key with "V" belts is the V needs to match the pulley geometry exactly -- or the belt does not make full contact. Also -- don't just think you can tighten them until the noise stops --- if the belts are too tight they will stress the bearings on the alternator and AC compressor -- both expensive.

[Buzzman]

The 3.5 engine uses a serpentine belt with a tensioner as the main belt, plus a smaller V belt.
The serpentine belt squeak is a common problem, especially in colder climates, first thing in the morning.
A new belt also tends to stretch after a few weeks, and usually starts squeaking.
The belt needs to be tightened as tight as possible. Crank the tensioner as tight as you can, and you're good to go. It won't break.

[yeldogt]

All three of my 2002's had V belts ... no Serpentine and tensioner. All 3.5's

[barnaclebob]

Mine used to squeel terribly when i lived in a colder climate. The car had an extended warranty and the dealer was never able to solve the prolbem. It went away when I moved somewhere where it rarely drops below freezing and after Midas changed the belts. The car still sees below freezing temps when it goes to the mountains in winter but no squeeling.

[honschoppt1]

Can anyone provide a link or diagram of the tensioner that needs tightened?

[04pathse]

Can anyone provide a link or diagram of the tensioner that needs tightened?

post6603473.html?hilit=changing%20belt#p6603473

[honschoppt1]

Thanks for that! If I'm reading this correctly there are two idler pulleys that need to be tightened? I don't have any kind of tool to gauge the belt tension but is there a general rule of thumb I can use?

[EdBwoy]

I read this in a manual, probably the FSM: it tells you to deflect the belt and to aim for around an inch* of deflection (can't recall if it wants you to push and pull, or just push the belt down)
It also points out where to deflect the belt (in the middle of 2 pulleys)

The FSM will probably get you there faster and more accurately , but the few times I've manually tensioned belts, it's been by feel. I just look at the old belt/guess the current deflection, then make a judgement call with the replacement/ tightening -Tight enough to not squeal the belt, loose enough to not stress the pulley bearings.

[Buzzman]

All three of my 2002's had V belts ... no Serpentine and tensioner. All 3.5's

Maybe it's just the way we define what a serpentine belt is, but I have 2 belts on the Pathy.
One "traditional" V belt that drives the A/C compressor, and one longer serpentine belt that drives the alternator and power steering pump.
The longer belt is flat on one side and has about 3 or 4 ribs on the other side. Without looking, I'd say it's about 3/4" wide. Not a V belt for sure.
It definitely has an adjustable tensioner on it as well. It's also the belt that squeaks the most.
I crank it as tight as I can get it.

[EdBwoy]

All three of my 2002's had V belts ... no Serpentine and tensioner. All 3.5's

Maybe it's just the way we define what a serpentine belt is, but I have 2 belts on the Pathy.
One "traditional" V belt that drives the A/C compressor, and one longer serpentine belt that drives the alternator and power steering pump.
The longer belt is flat on one side and has about 3 or 4 ribs on the other side. Without looking, I'd say it's about 3/4" wide. Not a V belt for sure.
It definitely has an adjustable tensioner on it as well. It's also the belt that squeaks the most.
I crank it as tight as I can get it.

I might need a Google refresher here, but my understanding was that a serpentine/poly -v/multi-v belt is only differentiated from a normal V belt in that it runs multiple accessories. It thus requires idler pulleys on the smooth side to snake it around... or serpent it around if you please.

[nalz]

A lot of serpentine belts do just as you have described, they snake their way thru multiple pulleys, and run along their "back " sides (the side without the ribs) , at times, to accomplish the original objective: to have one belt run the whole accessory drive show. There are exceptions though, and i think serpentine has come to refer to any flat, ribbon-like multi rib belt