High pitch whistle at start up - 986 Forum

cribfiller · 11-08-2016, 03:44 PM

I have searched a bit on this, MY 02 base has done this two times on cold start. The first the whistle lasted for ten or so seconds and the second, next day start, for four or five seconds. Car settles down and runs great. 91000 mi, I have owned last nine years, original AOS as far as I know. Zeroing in on this but any comments appreciated.

jb92563 · 11-08-2016, 04:57 PM

I have a similar high pitched "whistle" as do many others. My understanding is that its part of the pollution control system that injects extra air or something or perhaps purges a filter with the air.

I goes away in about 15 seconds and then does not recur until the next cold start.

Some are louder than others but not to worry because as you age your ability to hear high pitched sounds will decrease until you no longer hear it.

nieuwhzn · 11-08-2016, 10:42 PM

Yes, airpump, normal. Especially kicks in when it gets colder. Same ridiculous pollution control attempts as secondary cats and aos. I just spent $1,300 on a new first cat for my Saab Viggen because NY state has now adopted the same idiotic pollution controls as California. Both this first cat and the Boxster airpump serve the same purpose; decreasing emissions in the first minute of starting a cold engine. Total BS if you compare with the total emissions profile.

kk2002s · 11-09-2016, 07:08 AM

Ok so you have owned for a long time which means you are familiar with the Secondary Air pump (SAP) running roughly 90 seconds on a cold start.

Do you hear that high pitch 'whistle' from the right side of the engine compartment??
If so I suspect the Bearing in the SAP has lost it's grease (Just like the IMSB)

This bearing can be re-greased. I'm going on 2+ years after re-greasing with no high pitch 'whistle'

ymkmkrz · 11-09-2016, 10:33 AM

Good info. My 986 does this too, but 996 never has even though it has more miles by about 50k+

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cribfiller · 11-10-2016, 08:10 PM

Quote:

Originally Posted by kk2002s

Ok so you have owned for a long time which means you are familiar with the Secondary Air pump (SAP) running roughly 90 seconds on a cold start.

Do you hear that high pitch 'whistle' from the right side of the engine compartment??
If so I suspect the Bearing in the SAP has lost it's grease (Just like the IMSB)

This bearing can be re-greased. I'm going on 2+ years after re-greasing with no high pitch 'whistle'

Yes right, passenger side, of car. Thanks, I will do a bit of looking at this.