This bolt is touching the belt

[Vikas]

so the belt immediately comes off as soon as car is started. The rust bucket 2000 Maxima 3.0 VQ engine. I am suspecting compressor mounting has shifted or worse some front frame member cracked making the pulleys no longer in perfect plane any more. I lost lot of skin and blood trying to install the new belt from the top without taking apart anything even the splash guard shields. I was wondering how the old intact belt just dropped on the road. Well, after trying to put the new one, twice, I realized that something is seriously wrong :-(


The youtube video is here to show the offending bolt which I could only feel by my finger touching the belt.

Time Marker 12:50 aka 770 seconds; I am having trouble including the link with the start time.

[video:youtube]https://youtu.be/nz-eJ7cuSZA?t=770[/video]

 

[vw7674]

Is the A/C pulley attached to the compressor wobbling?
There's a roller bearing under that clutch/pulley. They can fail & toss the drive belt.

 

[Omahaug]

If you're talking about the bolt that appears to hold a bracket that holds a hose/pipe and sits right above the oil pan, if that bolt is locked into the engine block properly and the belt is touching it, the belt routing has changed or something is putting pressure on the belt.

1. Check all of the pulleys and the belt for any damage or anything out of place.
2. Are you sure you got the belt routing correctly? If you're incorrectly routing the belt maybe it's cutting past some pulleys? I say this is likely because you're trying to install the belt without removing anything and from the top even. It's very easy to misinstall in this manner due to parallax.
3. Are you sure the belt is the proper length? You mentioned a belt being tossed, could you have bought a new belt that is not the correct belt? Maybe a parts store or lookup mishap? You don't have the previous belt to measure against right?

I can see if the belt is both of the improper length and routed incorrectly, it could confuse you enough to think it's installed correctly when it's actually cutting past something and just happens to work (albeit with the belt touching the bolt) because the belt turned out to be shorter.

Double check your work, eliminate certain things and you'll find your answer. It is physically impossible for everything to be correct and this to occur. One or more things are not correct. Either the mounting point for the bolt has moved (if it's threaded into the block this is near impossible without catastrophic damage), one or more pulleys have shifted (also likely to be impossible, if the pulley has shifted parallel to the mounting point it would have broke the bolt holding it) or the belt is of the improper length or the belt is routed incorrectly.

 

[RayCJ]

Check the harmonic balancer on your crank pulley. Some have a rubber/elastic damper material that separates the inner part from the outer diameter. If the engine ever overheats or some other type of damage occurred, the elastic damper material can partially melt. The balancer will not spin in a flat axis and it will throw belts all day long. This problem is fairly uncommon but, not unhear of.

The enclosed picture shows the dark ring which is gap with the elastic material packed in there.


Ray

 

[Vikas]

All pulleys free wheeled fine with no wobble (except the crank pulley! which of course does not freewheel) I am suspecting compressor has shifted but that would only happen if the mounting bracket is broken or bent. The back story behind this vehicle is that my shop refused to work on this car when the first time alternator light flashed at me. They told me to get rid of the car as it has structural rust. I no longer drove it on the highway after that and parked it and had used it to go to grocery store half a mile away. I do want to use it to complete the manual driving training for my kid before I dispose it of.

I am avoiding jacking up the car and getting underneath it but at least I will try better to remove all the splash guards and to get a better look at it. The belt routing is pretty straight forward:- crank to compressor to alternator to idler to crank. When I put the belt back on, it was in the grooves all pulleys but it was not covering the idler fully and compressor pulley plane did not look parallel to all other three.

 

[mk378]

Is there an alternate belt arrangement for no A/C? Sometimes you can buy a shorter belt and put it on in a way that bypasses the compressor. (Really, for driving lessons around the neighborhood, you don't strictly need the alternator either).

But, an A/C compressor isn't going to relocate by itself.

 

[Vikas]

Originally Posted by mk378
Is there an alternate belt arrangement for no A/C? Sometimes you can buy a shorter belt and put it on in a way that bypasses the compressor. (Really, for driving lessons around the neighborhood, you don't strictly need the alternator either).

But, an A/C compressor isn't going to relocate by itself.

That would not work either because the compressor would be in the way and will not be able to bypass without taking it out of there.

I suppose I could put the battery on the permanent tickle charger and give driving lessons around the neighborhood.

 

[RayCJ]

Put a flat straight edge on the front surface of the harmonic balancer and note the angle it subtends with respect to other local objects nearby. Make a chalk mark on the balancer. Next, bump the engine and observe the chalk mark so that the balancer moves about 1/4 rotation or so. Put the straight edge on the surface again the same way as the first time and see if it subtends a different angle with respect to the same landmarks used the first time.

I've had 2 cases of this before in my lifetime. Once, the engine severely overheated and the elastic gap material in the balancer melted. This caused the center part of the pulley to spin on a different axis than the outer part that has the v-grooves. Second time, a belt broke, got wrapped around balancer causing the two parts of it to become partially separated and out of alignment.

In both cases, it visually appeared that the power steering pump or AC pulley were misaligned compared to the harmonic balancer. In fact, it was the other way around.

Ray

 

[RayCJ]

Put a flat straight edge on the front surface of the harmonic balancer and note the angle it subtends with respect to other local objects nearby. Make a chalk mark on the balancer. Next, bump the engine and observe the chalk mark so that the balancer moves about 1/4 rotation or so. Put the straight edge on the surface again the same way as the first time and see if it subtends a different angle with respect to the same landmarks used the first time.

I've had 2 cases of this before in my lifetime. Once, the engine severely overheated and the elastic gap material in the balancer melted. This caused the center part of the pulley to spin on a different axis than the outer part that has the v-grooves. Second time, a belt broke, got wrapped around balancer causing the two parts of it to become partially separated and out of alignment.

In both cases, it visually appeared that the power steering pump or AC pulley were misaligned compared to the harmonic balancer. In fact, it was the other way around.

Ray