Belt squeal only during start-up?
- Thread starter Frankiago
- Start date
I have the same issue. And it happens very randomly. I am thinking the pulley is pretty much wore out, so the belt slips during start up. My FX is over 120,000 KM
There are many reasons that belts squeal upon starting your engine. Pulleys with surface rust, weak belt tension spring, worn belt, fluid on the belt, among others. As for WHY it only happens upon start-up, I have a theory:
Cold rubber is less pliable than warm, in belts just like in tires. If any of the above stated issues arises, it is most likely going to start small and get progressively worse. At first it might be just enough to cause slippage until the belt warms up, which would be pretty quick considering the friction created by the belt slipping across a pulley. As the belt heats up it becomes more pliable and gains "traction" upon whatever it was sliding. The portion of the belt that doesn't touch a pulley when the engine stops would also probably cool very quickly relative to the engine block, so the process would repeat every time you start it up even if your engine is still warm.
Again, just a theory.
EDIT: Another possibility is that you have a bad battery, loose battery connection, or bad starter. Any of those may cause the alternator to work harder (require more torque from the belt) upon cold start-up to recharge the battery.
Cold rubber is less pliable than warm, in belts just like in tires. If any of the above stated issues arises, it is most likely going to start small and get progressively worse. At first it might be just enough to cause slippage until the belt warms up, which would be pretty quick considering the friction created by the belt slipping across a pulley. As the belt heats up it becomes more pliable and gains "traction" upon whatever it was sliding. The portion of the belt that doesn't touch a pulley when the engine stops would also probably cool very quickly relative to the engine block, so the process would repeat every time you start it up even if your engine is still warm.
Again, just a theory.
EDIT: Another possibility is that you have a bad battery, loose battery connection, or bad starter. Any of those may cause the alternator to work harder (require more torque from the belt) upon cold start-up to recharge the battery.
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So I had this exact issue and it was solved just by tightening the belts.
Just after I had my lightweight pulleys installed, I put in new belts and they would squeal only at start up. The shop I work with had me try a couple different things to identify which of the two belts was squealing.
Turn off the AC and see if it still squeals (belt 1). Turn the steering wheel to load the power steering pump (belt 2). This is what caused mine to squeal. A quick tightening stopped it.
I do think it has something to do with temperature and friction. If squealing is starting after driving on the same belts for a while, then maybe the belts are stretching a little. Don't think they need to be replaced unless you can see cracking or damage. Could be a little oil on a pulley as well - maybe just check to make sure the belts and pulleys are clean?
Just after I had my lightweight pulleys installed, I put in new belts and they would squeal only at start up. The shop I work with had me try a couple different things to identify which of the two belts was squealing.
Turn off the AC and see if it still squeals (belt 1). Turn the steering wheel to load the power steering pump (belt 2). This is what caused mine to squeal. A quick tightening stopped it.
I do think it has something to do with temperature and friction. If squealing is starting after driving on the same belts for a while, then maybe the belts are stretching a little. Don't think they need to be replaced unless you can see cracking or damage. Could be a little oil on a pulley as well - maybe just check to make sure the belts and pulleys are clean?
Cool, thanks guys. I'll check it out... it has 90,000 miles on it, belts should have about 15,000 miles. I'll find out if it's just a cold weather thing but I believe it only started happening when the temps dropped, I can't remember if it happened while warmer out.
I'll inspect the belts and pulleys this weekend and hopefully get that video of it.
Like I said before tightening isn't really doing the trick, but you may be right about the spring worn out on the tensioner pulley.
I'll inspect the belts and pulleys this weekend and hopefully get that video of it.
Like I said before tightening isn't really doing the trick, but you may be right about the spring worn out on the tensioner pulley.
the1obster
Member
i had the same problem too just tighten and its gone!!! gl
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Edit: other related information... the block was never supercharged, however, the pulleys and tensioners were swapped over from the old motor, maybe the extra stress of having to turn the charger pulley caused issues with the belt tensioner. After visually inspecting and if I don't find any signs of oil or wear on the belts, I'll probably narrow it down to the belt tensioner. I am pretty sure it's not the AC belt but I'll figure that out...
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you should sneak your camera out to show us your evo
FXchris305
Member
this happens to mine very rarely so i dont stress it . but i notice that if i turn off the AC it goes away. so wenever it happpens i just turn it off for a couple secs n turn it back on n good to go . i also noticed it started doing it after i changed to belts .but i dont know i dont really stress it on mine cause it almost never happens
If turning off the AC works, then it's because the belt attached to the AC compressor is a little loose. After it warms up and expands a little, the squealing stops. Still, there's no reason to have to do that - the proper belt tension should stop all squealing, no matter what temperature.
This problem everybody has is absolutely belt tension. If simply tightening them, "doesn't work" then loosen them and start over as if you were putting them on for the first time. Tighten each side a small amount in turn. Don't tighten one side all the way, then the other side. I seriously doubt the problem is caused by the tensioner, but it's always possible. Before spending the money on that, just try to re-install the belts again. Or have somebody else try it.
This problem everybody has is absolutely belt tension. If simply tightening them, "doesn't work" then loosen them and start over as if you were putting them on for the first time. Tighten each side a small amount in turn. Don't tighten one side all the way, then the other side. I seriously doubt the problem is caused by the tensioner, but it's always possible. Before spending the money on that, just try to re-install the belts again. Or have somebody else try it.