| Author |
Message |
Russ Gould (Russ)
New member
Username: Russ
Post Number: 20
Registered: 2-2003
| | Posted on Monday, May 26, 2003 - 12:05 pm: | |
An FNA technical guy told me that the exhausts whistle when the packing between the tailpipes and the perforated inner pipes wears away...this was obviously not the problem in this case but it may help others. It can be fixed but it's cheaper to ignore it...if you don't mind a turbine whining sound (pretend it's a turbo!) |
JohnR. (Rivee)
Junior Member
Username: Rivee
Post Number: 198
Registered: 1-2002
| | Posted on Monday, May 12, 2003 - 8:47 am: | |
I found it!!
Dr., it was the exhaust. When reasemblying the motor, I had capped off the smog fittings on the heads (right above the exhaust manifolds). I used the old fittings and brazed in the centers to close off the exhaust and one of them had a pinhole in the center where I had not brazed it good enough, so it was like a whistle.
Thanks all for your response. |
Verell Boaen (Verell)
Member
Username: Verell
Post Number: 724
Registered: 5-2001
| | Posted on Sunday, May 11, 2003 - 10:18 pm: | |
Odds are that the alternator belt isn't quite tight enough. Being used to the belt tension on cars w/the old 1/2" wide V-belts, I was very surprised at how much more tension the thin Gates PolyFlex belts Ferrari uses require. I had to increase the tension on my alternator belt 3 times before I got it to stop chirping. |
Lawrence Coppari (Lawrence)
Member
Username: Lawrence
Post Number: 602
Registered: 4-2002
| | Posted on Sunday, May 11, 2003 - 11:32 am: | |
Run the motor for a very short period of time with the accessory belts off. Don't know what a 308 has but a 328 has three. If noise is not present then, put one back on and so forth. At least this way you can eliminate alternator, water pump, AC. |
"The Don" (Mlemus)
Advanced Member
Username: Mlemus
Post Number: 4596
Registered: 8-2002
| | Posted on Sunday, May 11, 2003 - 10:45 am: | |
Timing? |
Dr. I. M. Ibrahim (Coachi)
Member
Username: Coachi
Post Number: 264
Registered: 5-2002
| | Posted on Sunday, May 11, 2003 - 9:52 am: | |
upon further reflection, the chirping maybe coming from your exhaust. I had that problem some years ago. It did finally go away, after some tinkering with the resonators |
Dr. I. M. Ibrahim (Coachi)
Member
Username: Coachi
Post Number: 263
Registered: 5-2002
| | Posted on Sunday, May 11, 2003 - 9:48 am: | |
A crazy idea...but my 308 was chirping at low speeds for some time, and just recently, my water pump froze. Did you check you water pump? |
JohnR. (Rivee)
Junior Member
Username: Rivee
Post Number: 196
Registered: 1-2002
| | Posted on Sunday, May 11, 2003 - 9:28 am: | |
Matt, it does it ALL the time and I think it gets louder when it warms up |
"The Don" (Mlemus)
Advanced Member
Username: Mlemus
Post Number: 4594
Registered: 8-2002
| | Posted on Sunday, May 11, 2003 - 8:56 am: | |
If it's on warmup, Ferrari told me it was a check valve opening and closing and not to worry about it. |
JohnR. (Rivee)
Junior Member
Username: Rivee
Post Number: 194
Registered: 1-2002
| | Posted on Sunday, May 11, 2003 - 8:53 am: | |
^ |
JohnR. (Rivee)
Junior Member
Username: Rivee
Post Number: 193
Registered: 1-2002
| | Posted on Sunday, May 11, 2003 - 8:35 am: | |
Mike, the sound is coming from somewhere in the motor compartment.
If it is a leaking exhaust manifold chirp I'm hearing then covering one exhaust tip at a time might make the chirp stop temporarily thus exposing the problem |
Mike Charness (Mcharness)
Member
Username: Mcharness
Post Number: 508
Registered: 8-2002
| | Posted on Sunday, May 11, 2003 - 8:23 am: | |
It may be the exhaust? I had that on my 308QV some years back. Only shows up at low RPM. Try using your hand (or a board or something) to cover up each of the 4 exhaust tips one at a time. If it *is* one of the exhaust tips, that's because the packing around the baffle has burned out, causing the chirp or whistle. It drove me NUTS for months, trying to figure it out and come up with a solution, think it was a general exhaust leak before I narrowed it down.
If that's what it is, the easy fix is to put a "roll" of stainless steel sheet inside the baffle. If that's your problem and you'd like pictures, I'd be glad to share them.
|
JohnR. (Rivee)
Junior Member
Username: Rivee
Post Number: 192
Registered: 1-2002
| | Posted on Sunday, May 11, 2003 - 8:09 am: | |
I recently completed a rebuild on my 308. I started it a couple of days ago and it fired up right away and sounds great except at idle when it makes this sort of chirping noise. It does it all the time under about 1300 rpm and I can't tell where it's coming from. It's fairly noticable and seems to be getting louder also.
I first thought that it was a belt or pully, but the water pump, alternator, timing belts, tentioner bearings and throwout bearing are all new. I don't have the AC hooked up yet so it can't be that.
It's a definate chirp and not a rattle that is in sync with the rpm's.
Any ideas? |