ddub

Ok, here's the story...

I went to the track tonight to do some runs. After my first two runs everything seemed fine. I turned off my car for a bit while the drag cars did some runs. Started my car up and when I first drove forward I heard some screeching, so I popped the hood, didnt see any problems and drove some more and it went away... figured it wasn't anything that big. On my 3rd run I did my best, and took it a little bit too far past redline because I didn't notice it right away, however normally I've been shifting at 7500 on each shift when dragging, but this time it almost went to 8k lol!! oops, oh well. Anyways, after I pulled over to look at my time and stuff, the screeching came back, but now it was worse, eventually it went away again. I checked the belts and they were tight, but felt kinda HOT. I let the car sit and cool for a while, started it up and the screeching was worse than ever but then stopped again. Did another run deciding it would be my last, and oh was it my last... Worst run ever, things were messed up or something. Decided to go home at that point, got on the freeway and immediately I hear a snap and THUD THUD THUD under my hood. I pulled over, and turns out my alternator belt SNAPPED IN HALF. I eventually got home thanks to my friend (who was with me) having his dad take the alternator belt off of his TII and bring it to us with tools to put it on. Put it on, screeching still there at first... So it wasn't just the belt.

Here are my thoughts. I am guessing that the water pump is on its way out, and it seems like when I'm first starting out (when the screeching happens the most) the water pump may not be spinning or something. And it also seems like it either isn't spinning as fast all the time, or sometimes stops for a second, something like that. Because, the belt got pretty warm, so I was thinking that the water pump not turning would cause friction which eventually made the belt get too hot and snap. Does that make sense? Sound like what's causing it? Anyone else have any other ideas on why this is happening?


Well, on a good note, I ran a 15.3 tonight in my 88 n/a stock port

gildardo

might just be an old belt. My TII ate one in a week, but i think it was due to not tightening it right the first two times ill see how long this one last. mine had the same simtomes like yours. I guess once the belts start to slip it's gone as they seem to not get thir grip again. Same kind of thing happed with my brothers AE86.

just install a new one and remmember to tighten it two times. tighten it once than run the engine for 5 to 10 minutes or so and tighten it again.

It coud also be your alternator that is getting to stiff.

ddub

The belt was brand new, a couple weeks old. So I don't think it would be the belt's fault. Plus, my friend's belt from his TII which has no screeching ever (that we put onto my car) screeched imediately on mine. So I'm thinking it's something else.

gildardo

whell I had installed one new one a couple weeks ago and then last week it started to screech and slip then it brocke in half. So, It might be that you didn't install it right i didn't. Did you tighten it two times like the instructions said. But then again you might be right, becaus if you used one that was broken in already and it started to screech than it coud be the water pump like you said or the alternator. How old is your alternator and water pump.

ddub

This is interesting, I just read this thread with a guy with an FD alt, which I also have.

https://www.rx7club.com/showthread.p...postid=3037064

KNONFS

iTrader: (14)

How are the alternator & water pump pulleys? Do they turn without any problems (freely)?

j9fd3s

iTrader: (3)

might be the new belt stretched and was loose, they do this especially if its made in the usa. i went thru like 3 belts on my miata, they would stretch out so far it was still loose enough to flip upside down, and the tension was maxed out.

ddub

Ok... But remember I put my friend's belt in that was off his TII that was fully broken in and had NO problems on his car. After putting it in, it imediately started screeching

ddub

Bump...

The pulleys seemed to spin fine last night (by hand) so I'm not sure what's causing it.

I went to that other thread about the FD alt that I posted earlier and checked the things suggested there. I DO have the spacer for my alt, it is aligned, and it is not wobbly at all... So I'm kinda stumped here, anyone have an idea?

MRX_Rotary

The day I bought my car, it had the same symptoms. about 2 miles from home of the 3 hour drive, the belt snapped, and it was driven the rest of the way on battery power. The next day, a new belt was put on and it hasn't screeched since. Maybe it's a fluke?

Edit: Wait, it did screech a little with the new belt on, but it went away. Maybe it juust needs time.

ddub

OK....


I'm a dumbass. My pulley on my alternator wasn't lined up properly which is why when drag racing the friction caused the belt to heat up and snap. It wasn't lined up because the spacer for the alt was in the front instead of in the back where it should be when I checked it today. So I switched it to the back and the pulley lines up perfectly now and everything. So I'm an idiot

For those interested, here's what a belt looks like that's been abused from an unaligned pulley causing it to snap




These teeth on the belt were the only good ones left. These are semi-worn (not as good as when I bought it) but you get the idea of what it should look like.




And here, you can see the abuse the belt was going through