| Author |
Message |
Barry Wolinsky (308gtb)
Member
Username: 308gtb
Post Number: 710
Registered: 2-2002
| | Posted on Thursday, October 16, 2003 - 4:12 pm: | |
Yes indeed, Dave. I checked into my belt noise a little further this morning and it is the alternator belt.
Barry |
Verell Boaen (Verell)
Intermediate Member
Username: Verell
Post Number: 1236
Registered: 5-2001
| | Posted on Wednesday, October 15, 2003 - 3:00 am: | |
The cam belts are only risky if the flapping is because a tensioner has loosened up, or because a piece of the belt has separated & is flapping.
Both of theses are unlikely since the noise goes away after warmup.
The tensioner can be checked by putting a wrench on the tensioner bolt & gently trying to see if it's loose. Best to use a torque wrench set to about 1/2 the torque specified for the tensioner bolt. If the bolt rotates well below the specified torque, then the belt must be replaced.
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Dave328GTB (Hardtop)
Member
Username: Hardtop
Post Number: 684
Registered: 1-2002
| | Posted on Tuesday, October 14, 2003 - 9:51 pm: | |
This question comes up frequently, especially with colder weather coming on. The noise is almost certainly the alternator or ac belt. In our current Rocky mountain charpter newsletter, Fcar mechanic Dave Helms says the belts are relatively thin and will slap when cold. After the motor warms and expands, the belts tighten and the noise disappears. I have experienced this myself and it seems to be pretty universal among 328 owners and also QV owners. When the belts are new, it usually won't make the noise, but after they have stretched a little, it starts. Best advice, leave them alone.
Dave |
Ton Visser (Lion315)
Member
Username: Lion315
Post Number: 724
Registered: 12-2002
| | Posted on Tuesday, October 14, 2003 - 6:16 pm: | |
The belt noise can also be the static noise of the airconditioning belt. That usually disappears after a few minutes.
Ton |
Phil Hughes (Ferrarifixer)
Junior Member
Username: Ferrarifixer
Post Number: 236
Registered: 7-2003
| | Posted on Tuesday, October 14, 2003 - 6:55 am: | |
If it is the cambelts flapping, the WORST thing you can do is to let it idle while it warms up.
The likelyhood of a cambelt breaking at idle is massively more than while running under a light load.
Raise the rpm until the noise stops and warm it up there.....or get the cause fixed and the symptom will take care of itself! |
Phil Hughes (Ferrarifixer)
Junior Member
Username: Ferrarifixer
Post Number: 235
Registered: 7-2003
| | Posted on Tuesday, October 14, 2003 - 6:52 am: | |
It's very common and quite unimportant that the w/pump and a/c belts make a clicking sound. They're the "gates" type with strands inside.
Simply give a quick squirt of WD40 or silicon spray at the auxilary belts while it's making the noise and it will instantly disappear if it is the cause.
If the noise stays after a couple of short squirts at each belt, then get further advice. |
Lawrence Coppari (Lawrence)
Member
Username: Lawrence
Post Number: 793
Registered: 4-2002
| | Posted on Tuesday, October 14, 2003 - 6:19 am: | |
These engines are aluminum. Aluminum has a very large coefficient of thermal expansion. When the engine block warms, it causes the pulleys to be a greater distance apart. That tightens the belts. The belts are not as hot as the engine nor do they expand as much due to their material.
If it were my vehicle, I would check the cam belts to determine if either is loose or damaged. You can feel the front one by running your hand down the cover. The rear is readily accessible. The tension on the belt (downstream of the belt drive pulley) varies depending on where the crank is in its cycle. |
TOM BUCKLEY (Tom_b)
Junior Member
Username: Tom_b
Post Number: 117
Registered: 6-2003
| | Posted on Tuesday, October 14, 2003 - 5:08 am: | |
Barry,
Interesting. I started getting the same noise about 2 months ago. Once the car is warm it disappears. I've put a stethoscope near various belt shrouds and can't seem to pin down the location. Are you sure it's the cam belts ? I thind i'll stop by the dealer this week and ask my mechanic.
Tom |
Barry Wolinsky (308gtb)
Member
Username: 308gtb
Post Number: 706
Registered: 2-2002
| | Posted on Monday, October 13, 2003 - 8:49 pm: | |
John,
It's not uncommon to hear some "flapping" noises from the belts for the first few minutes after start-up. The timing belts will make a slapping sound when cold at times. Now that fall is here, I guess we'll be hearing that more frequently. I get the same thing with my 308 GTB on these crisp mornings. I let my car idle a bit longer on days like these before I move off to allow the everything to warm up in the engine bay.
But as Anthony said, for peace of mind let your mechanic check the belts and tensioners.
Barry
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Anthony Millman (Frari)
New member
Username: Frari
Post Number: 12
Registered: 6-2003
| | Posted on Monday, October 13, 2003 - 7:29 pm: | |
John if I were you I would get this on a flat bed and take directly to mechanic. One of our club members had a similar noise and discovered that it was a flap in the belt that was caused by a stone cutting into the belt and almost severing it. this was flapping as he drove and making this flap flap noise. Best to be cautious. |
john roberts (Jr328gtb)
Junior Member
Username: Jr328gtb
Post Number: 62
Registered: 5-2003
| | Posted on Monday, October 13, 2003 - 7:11 pm: | |
my 328 seems to be making a belt noise (sounds like flapping). it only happens for the first 5-10 minutes and then seems to stop.
i have read about tightening the belts but is there any risk to driving the car while this is happening.
it is not really loud and i wonder why it stops also
thoughts??? |