Metallic hissing from 997.1 S engine bay at 3900 RPM?
#1
Metallic hissing from 997.1 S engine bay at 3900 RPM?
My car is a 2006 Carrera S with about 47k miles on the odometer. Anyone else have this happen? I get a "ssssssss" metallic hissing sound coming from the engine bay as I'm driving ONLY when the revs are at 3900 RPM exactly. Usually I don't notice as I'm passing through 3900 pretty quickly, but if I hold it at 3900, the hissing comes up and holds steady until I move off 3900 RPM.
No power loss, no warning lights, no other noises or other trouble.
It's not a turbo, so it's not that.
The only other thing I did was an oil change about 50 miles ago, using Motul 8100 5W40.
This just started happening so I haven't had a chance to isolate where in the engine bay it's coming from.
Is it the variocam?
No power loss, no warning lights, no other noises or other trouble.
It's not a turbo, so it's not that.
The only other thing I did was an oil change about 50 miles ago, using Motul 8100 5W40.
This just started happening so I haven't had a chance to isolate where in the engine bay it's coming from.
Is it the variocam?
#3
If the car has an after market exhaust or headers, a hissing noise is common on all sports cars particularly with headers. If it has aftermarket exhaust/headers there is likely no problem with the car at all..
#5
#7
How does the Varioram system work and at what RPM is the intake length changed? Seems like it might be right around that 3,900 RPM #. Just putting that out there as a guess.
Trending Topics
#11
Absolutely will follow up on this! So the two possibilities so far are:
1) Vacuum leak
2) Serpentine belt pulley
Will be checking on these things next week. Would anyone think these possibilities are serious enough for me to cancel a morning drive through the canyons over the long weekend?
1) Vacuum leak
2) Serpentine belt pulley
Will be checking on these things next week. Would anyone think these possibilities are serious enough for me to cancel a morning drive through the canyons over the long weekend?
#12
Absolutely will follow up on this! So the two possibilities so far are:
1) Vacuum leak
2) Serpentine belt pulley
Will be checking on these things next week. Would anyone think these possibilities are serious enough for me to cancel a morning drive through the canyons over the long weekend?
1) Vacuum leak
2) Serpentine belt pulley
Will be checking on these things next week. Would anyone think these possibilities are serious enough for me to cancel a morning drive through the canyons over the long weekend?
#14
Any gear, through accel and deccel ?
How about neutral ? Someone run it up in neutral while you listen both sides, under rear wheel house too.
Maybe heatshield touching muffler, or it not completely secured ?
How about neutral ? Someone run it up in neutral while you listen both sides, under rear wheel house too.
Maybe heatshield touching muffler, or it not completely secured ?
#15
This happens when the engine is at operating temperature, in any gear including neutral, and it happens going up through 3900 RPM during acceleration, as well as down through 3900 RPM the other way during decceleration.