Welcome to RennTech.org Community, Guest
There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.
Here are some of the features available - once you register at RennTech.org
- View Classified Ads
- DIY Tutorials
- Porsche TSB Listings (limited)
- VIN Decoder
- Special Offers
OBD II P-Codes
- Paint Codes
- Videos System
- View Reviews
- and get rid of this welcome message
It takes just a few minutes to register, and it's FREE
Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)
- No ads - advertisements are removed
- Access the Contributors Only Forum
- Contributing Members Only Downloads
- Send attachments with PMs
- All image/file storage limits are substantially increased for all Contributing Members
- Option Codes Lookup
- VIN Option Lookups (limited)
This squealing sound was definitely random and "non-controlled" in nature. I am visualizing that the water pump impeller's bearings are somewhat halfway getting pulverized (sounds very painful) as fluid (coolant) continues to try to circulate. The grinding / squealing are probably caused by dis-membered ball bearings that are either stuck together as they try to rotate along the retainer and sleeve within the housing....very nasty!!! Thanks again everyone for this brainstorming session. I'll keep you guys in the loop for any other developments.
didn't get a chance to update you guys on this matter....didn't get back to it till last night but here are my observations: - so i ran the engine for a few moments without the belt and the strange noise was not present which was great so it must be one of the accessories as all of you mentioned. - next I spun each pulley / idler / accessory and nothing popped out of the ordinary in terms of resisting rotation or excessive play/wobbling. - so i reconnected the belt and started the engine again to diagnose further. Took a really bright lamp and shown it on the fully exposed rotating belt pulley/idlers etc... as the engine was running. What i noticed is that there was a slight wobble (the kind only you would notice if you were to shine intense light on) on the water pump pulley and it synched with this aweful sound. So I went underneath placed my ear relatively near the pump housing which is visually accessible directly beneath the car. The noise definitely was coming from it because when i touched the housing (that's because I didnt have a stethoscope) I felt this vibrating sensation that again, synched up with the aweful noise. I also tried resting the tip of a long screwdriver and placing the back of the handle against my ear and confirmed this grinding vibration. Also tried this trick on the rest of the accessories (alternator, compressor, idler, tensioner..etc...) what I heard were slight and smooth vibrations - 10 folds less intense than with the water pump. So I ordered a new pump arriving tomorrow morning and a video I found to perform the replacement...stay tuned..
Painful sound during 0:32 - 0:35 in the video I haven't tried it with the A/C on... I will do that.. thanks mxt_77 @Loren: Never tried turning the engine with the belt off...is that safe? @Loren/Paulspeed: Brand new belt. I've physically taken off the belt and spun each pulley / bearing by hand....no wobble or resistance to rotation observed. Thanks everyone!
I have a 2006 C4 with 49K miles and from a cold start, I began hearing this intermittent grinding noise on top of the regular engine hum during idle. This strange sound would go in and out just like how a locomotive would sound with intermittent whinning noise (which sounds very painful to me by the way). I took off the Air intake assembly to inspect the serpentine belt and the various pulleys, bearings and snubbers. They all seemed fine. I've attached a link to the video so you all can see. thanks