Notices
996 Forum 1999-2005
Sponsored by:

strange engine sound

Thread Tools
 
Search this Thread
 
Old 04-29-2012, 05:50 AM
  #1  
SubzeroX
Racer
Thread Starter
 
SubzeroX's Avatar
 
Join Date: Jan 2012
Posts: 332
Likes: 0
Received 0 Likes on 0 Posts
Exclamation strange engine sound

so i noticed yesterday, right after i did that PSE cutout mod, a new engine sound.. and not the sound i was looking for.

I have an MY03 coupe


1) it comes and goes.
2) its only there when the RPMs are coming down (not present at idle, not present when gasing it, doesnt matter what gear/neutral. When i hit the gas and let go, the engine will vroooom up and on the way down i'll hear the sound till it disappears on idle).
3) cant really notice WHEN it comes or WHY, but just randomly comes and about 30 seconds later it disappears. First time i heard it was when i was coming to a red light from afar and kept it in gear. Then at the red light, while in neutral i gassed it, and on the way down the sound was there immediately till disappeared in idle. next red light it was gone. Happened again day after (today)
4) it sounds like a fast clicking z sound, so on the way down its like a ZZZZZZZZZZZZZZZZZZZZ, fairly loud to be heard while sitting in the car.




PLEASE tell me it's not some engine issue
Old 04-29-2012, 03:14 PM
  #2  
SubzeroX
Racer
Thread Starter
 
SubzeroX's Avatar
 
Join Date: Jan 2012
Posts: 332
Likes: 0
Received 0 Likes on 0 Posts
Default

no thoughts?
Old 04-29-2012, 04:46 PM
  #3  
eidolon
Instructor
 
eidolon's Avatar
 
Join Date: Dec 2005
Location: Portland, Oregon
Posts: 198
Likes: 0
Received 0 Likes on 0 Posts
Question

Originally Posted by SubzeroX
no thoughts?
That one has me puzzled bro... I almost wanted to believe that it was a similar problem to mine when I lost my thrust bearings but if your engine is not shutting down when it gets to normal operating temp I would not say your situation is as dire as my past experience.

Could it be related to the PSE relay as the engine is winding down in rpm?
Old 04-29-2012, 04:51 PM
  #4  
eidolon
Instructor
 
eidolon's Avatar
 
Join Date: Dec 2005
Location: Portland, Oregon
Posts: 198
Likes: 0
Received 0 Likes on 0 Posts
Default

Sorry scrap that last post... I see from another thread you are quite intimately familiar with the PSE relay!

Sorry bro... I have no clue.
Old 04-29-2012, 04:54 PM
  #5  
SubzeroX
Racer
Thread Starter
 
SubzeroX's Avatar
 
Join Date: Jan 2012
Posts: 332
Likes: 0
Received 0 Likes on 0 Posts
Default

haha yea i took out the relay , i'm thinking it can be that maybe
Old 04-30-2012, 01:12 AM
  #6  
Hurdigurdiman
Drifting
 
Hurdigurdiman's Avatar
 
Join Date: Sep 2011
Location: Ephrata, PA, USA now. Originally from the UK
Posts: 3,075
Likes: 0
Received 19 Likes on 15 Posts
Default

Only thinking?
Old 04-30-2012, 01:24 AM
  #7  
jfintexas
Instructor
 
jfintexas's Avatar
 
Join Date: Mar 2012
Location: North Texas
Posts: 144
Likes: 0
Received 1 Like on 1 Post
Default

I did the same diode removal. I had mine out for city and highway combined 150 miles today. No sound like what you describe. I have a cab so maybe I need a quieter environment to notice if it was for sure.
Old 04-30-2012, 02:33 AM
  #8  
speed rII
Pro
 
speed rII's Avatar
 
Join Date: Aug 2010
Location: Finland
Posts: 529
Likes: 0
Received 0 Likes on 0 Posts
Default

https://rennlist.com/forums/996-foru...ght=engine+fan

something like this?
Old 04-30-2012, 03:42 AM
  #9  
SubzeroX
Racer
Thread Starter
 
SubzeroX's Avatar
 
Join Date: Jan 2012
Posts: 332
Likes: 0
Received 0 Likes on 0 Posts
Default

sounds like that, more like a winding zzzzz and its only present while the RPMs are coming down. disappears at idle and upgoing rpm
Old 04-30-2012, 03:59 AM
  #10  
eidolon
Instructor
 
eidolon's Avatar
 
Join Date: Dec 2005
Location: Portland, Oregon
Posts: 198
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by speed rII
OMG! That sounds awful!!!
Old 04-30-2012, 12:57 PM
  #11  
logray
Three Wheelin'
 
logray's Avatar
 
Join Date: May 2010
Location: Nor Cal
Posts: 1,851
Likes: 0
Received 6 Likes on 6 Posts
Default

I haven't listened to the sound, but get the car on a lift and isolate where the noise is coming from. Use a mechanics stethoscope if you need to.

If it's coming from inside the engine don't run it until it is fixed.
Old 04-30-2012, 03:08 PM
  #12  
fpb111
Rennlist Member
 
fpb111's Avatar
 
Join Date: May 2008
Location: Northern NJ
Posts: 5,535
Received 93 Likes on 69 Posts
Default

Try it with the oil cap off. If it only happens with high manifold or crank case vacuum would point toward AOS.



Quick Reply: strange engine sound



All times are GMT -3. The time now is 08:00 PM.