Car: 2010
Cayman
MT6 with ~86K miles. Only about 50K on this 9A1 engine and all accessories (long story but replaced 01/2012 under warranty @26K with a brand new 2012 engine from factory. Came ready to go with all belt-driven stuff).
Last week I suddenly started hearing a new noise from the engine compartment. Hard to describe - not a squeal. More a rhythmic whirring. Since it was also occurring when stopped and increased with engine speed, I hoped it was something belt-driven. With 50K miles on the WP, I went ahead and ordered one along w/ serpentine belt and a gallon of coolant. While waiting, I only drove the car for short distance errands.
I figured that even if the WP was good, I'd have a new spare for the inevitable. I was planning on digging-in today after prepping the car last night. Engine covers (top and front) removed, all corners on jack stands. Serpentine removed from tensioner.
Initial inspection:
ran engine for 30 seconds with belt slackened - sounds normal
tensioner pulley didn't feel any play, looseness or sound - spun feely
water pump pulley - smooth and quiet
a little drag feel on the A/C compressor - maybe that's normal. Didn't sound like the problem
PS pump makes a knocking sound when rocked back&forth. Could be what I heard
See the video (I hope it plays):
So, assuming it is the PS pump, what's the danger of waiting a little longer? I've not noticed and slop of unusual feel in the steering. I checked the PS fluid and it is in full to the cold make. I'm thinking a failure (short of catastrophic explosion) might make steering kind of stiff but shouldn't damage anything.
In reality, I don't know whether to be happy (that it's not the WP) or disappointed. This isn't like a water pump failure that could destroy an engine. But I've mentally prepared myself on what I'd need to do to replace the WP - even picked-up some extra tools. From a quick search, seems PS pump is a bigger PITA to replace - even though it is on top of the engine. I'm thinking of putting the belt back on and taking it to my indy.
UPDATE. I put the serpentine back on and ran the engine again. Using some flexible tubing as a make-shift stethoscope I found that the noise seems to be coming from the A/C compressor. I get basically the same sound whether A/C is on or off. I'm now checking if the clutch (or whatever that is hidden inside the pulley) is replaceable. AC seems to work fine. I think I'm gonna drive around some more before I button up the engine.
I had the same thing happen, and it ended up being the water pump. When the sound started, I pulled the front cover and inspected. No leaks, water pump pulley
felt
fine with no play. I continued to drive it for a while - the sound evolved and after about a hundred miles pulled the cover again. Now it was obviously the water pump, some seepage of fluid and a bunch of play in the shaft. Replaced the pump, flushed and filled the fluid, good to go.
Not saying yours will be the same, but it's definitely possible.
If it is your PS pump, I suppose worst case would be it seizing and burning up the belt.
You might try putting the belt back on and running the car in the garage with the cover off. You can use one of those stethoscope things to listen to the various belt-driven components.
I had a whine, ended up replacing my
power steering pump
. Pretty close to the A/C compressor, could be what you heard.
-PM.
Update: turns out the "whirring" sound kept getting louder and with a stethoscope I was able to pin-point it as the AC compressor. Replaced the Pulley & bearing (as a unit) solved the problem. All work was done from the front access panel. No need for removal of the compressor. Pleased to report all is now good!
Excellent outcome!
Sent from my XT1650 using Tapatalk
Rschwerer glad you managed to find the source of the issue and a way to resolve it without changing the entire compressor and clutch assembly. Do you have any pics or part numbers for the clutch bearings/pulley?
I was disappointed that PET did not show a separate part # for the pulley/bearing. They want you to buy a whole new compressor. I'll just summarize some details and leave-out the ugly details of mistakes I made during removal. Actually I'll leave them in so others can avoid them.
To see the actual pulley hub, you first need to pop-off a rubber dust-cover that covers the entire hub face (not pictured below). Just use a flat-blade screw-driver in one of the outside-edge gaps. I took a picture of the hub and saw "
Denso
" and what appeared to be a part number "PPS-GF40". I then Googled that number and found several hits. But it took some time to find the hub for
Porsche
. I finally found an ebay seller:
AC Compressor Clutch fits Mercedes C230 E350 Porsche 911 Boxster Cayenne 157360
which looked right and claimed to be compatible.
Since this compressor is "clutchless", there is no coil behind the pulley. Most Youtube videos on replacing the pulley are for an older style. But I later found a good video for a similar model:
7SEU pulley replacement
. Except he was doing it on a bench instead of in-car. I wasn't worried since it is readily accessible from the access behind the seats.
I alluded to mistakes. I wish I'd seen this video before I started. I'd know that the hex head in the center was
not
a bolt but the end of the compressor's shaft. You can't unscrew it like in the old-style compressors. I
did
try and rounded the head. So I needed the hub removal tool he shows at the end of the video.
A/C Compressor Clutch Removal Tool for Denso 6SEU & 7SEU Compressors
$49 on ebay. This is only needed if you can't remove the hub the "normal" way. Warning: if you use this tool, don't insert the 3 barrels fully into the hub. In my case, it sheared part of shaft that held the snap-ring on behind the hub. Just insert it about 1/2 way. Now I can't re-attach the snap-ring but I'm not too worried since that new bearing fits so tight it isn't going anywhere without a gear-puller.
Second mistake: use a hub/gear-puller to get the old pulley off. It is really on there tight. Buy or borrow one with 2 or 3 prongs and capable of a 5" spread. Mine was too small to grip the pulley (which is just plastic) from behind. I ended-up destroying the pulley - leaving just the metal case-hardened bearing pressed to the shaft. Then I had to use 2 short flat-blade screwdrivers to carefully pry the bearing case out enough to use my gear puller.
Final issue: after getting it all together, I started getting belt squeal when I revved over 2K RPM. That's when I noticed that the new pulley was wider than the old one. It had two more groves. When I first re-installed my serpentine belt, I didn't notice the difference and set the belt flush with the front lip. So I loosened the belt tensioner and moved the belt to the back of the pulley. That solved the squeal. So - maybe the pulley I was sold wasn't correct. I'm not worried since the grooves in the pulley should keep it on track. Time will tell. If I need to do this again, I'd look closer for another vendor.
Here is the original noisy pulley before my destruction.
Here is the pulley with hub removed - pulley and bearing still attached. Notice the rounded shaft head and partially destroyed snap-ring lip (due to improper use of removal tool). Notice there's 6 rubber spacers that should also be in the new pulley. Also notice the washer/spacer (on the threaded shaft) that you MUST re-use on the new pulley. And don't forget to remove the snap-ring:
And finally, here is the remains after my attempt to remove the pulley without a gear-puller. DON'T! Bearing still pressed on the shaft had to be pried-off with 2 short screw-drivers.
