993 Whistle on blip and steady revs, with video
Discussion
Morning all
I’ve had a whistle from my engine bay since I got the car a month or so ago, you can hear it in the video below. It’s a 1994 Carrera 2 with no mods, and there is no impact to performance.
https://youtu.be/KqBKJP7oTzk
It happens only on throttle blip, and when under load at between 1800-2400ish RPM, annoyingly at cruising speed!
The car runs and idles well, it holds vacuum, everything that can be tightened up externally has been, ISV cleaned out, MAF housing reseated, airbox cover ruled out, new stock air filter...
I now suspect it’s the throttle body itself, or perhaps the throttle position sensor, given the immediacy of the noise on blipping.
Does anyone have any further suggestions?
Thanks in advance.
I’ve had a whistle from my engine bay since I got the car a month or so ago, you can hear it in the video below. It’s a 1994 Carrera 2 with no mods, and there is no impact to performance.
https://youtu.be/KqBKJP7oTzk
It happens only on throttle blip, and when under load at between 1800-2400ish RPM, annoyingly at cruising speed!
The car runs and idles well, it holds vacuum, everything that can be tightened up externally has been, ISV cleaned out, MAF housing reseated, airbox cover ruled out, new stock air filter...
I now suspect it’s the throttle body itself, or perhaps the throttle position sensor, given the immediacy of the noise on blipping.
Does anyone have any further suggestions?
Thanks in advance.
Get a stethoscope on your Fan Shroud - it could be [one of] the Alternator Bearings..
https://youtu.be/VHNRMEd9Wbc
https://youtu.be/VHNRMEd9Wbc
Edited by kingroon on Thursday 22 August 11:25
I've just fixed it, but it wasn't easy.
I removed the throttle body, which on a 993 is the most difficult thing in the world (or at least if felt like it was at the time) cleaned the whole thing out and replaced all the o-rings. I also noticed that the metal throttle body was connected to the plastic intake manifold with 4 M5 x 18 pan head bolts, there were metal 'gripper' style nuts within the plastic which had been pulled out in the past by over tightening. I managed to compress these back in but I've ordered some M5 x 30 bolts and nuts to replace these and ensure a tight fit.
I removed the throttle body, which on a 993 is the most difficult thing in the world (or at least if felt like it was at the time) cleaned the whole thing out and replaced all the o-rings. I also noticed that the metal throttle body was connected to the plastic intake manifold with 4 M5 x 18 pan head bolts, there were metal 'gripper' style nuts within the plastic which had been pulled out in the past by over tightening. I managed to compress these back in but I've ordered some M5 x 30 bolts and nuts to replace these and ensure a tight fit.
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