Strange Engine Noise with Video

2006 Cayman S Manual I have this engine noise that is intermittent making it much harder to diagnose. It began last week when I noticed it while driving in a parking lot. The noise continued through my next two destinations but by the time I got home I couldn't hear it anymore. The noise was there again throughout the next day but then stopped that night on the way home from work. It didn't return until this weekend and it really sounded bad. I've been driving around with the engine covers off so that when the noise starts I have a better chance at locating it. The noise can start unexpectedly and stop unexpectedly. I am not running the AC at all. No coolant loss. Power steering fluid is full. The noise can be present at cold startup or when warmed up. The noise sounds external to the engine so I'm pretty sure it's something belt-driven, so I popped the belt off to check the pulleys. There is no forward or back play in any of them, the water pump feels firm but can be rotated in one direction without issue (reversing direction makes it stick a little, but I'm assuming that has to do with the direction it's trying to push the fluid), I discovered the clutched alternator which I've never seen before, the idler and tensioner pulleys feel good but rotate about as well as a cheap skateboard wheel but with no real noise, and the power steering pulley has some rotational play in it that I'm not sure is normal. Have a listen to my videos, the noise in question is the rhythmic sound that's kind of like a big clock ticking. It changes in relation to the RPMs. Last night I pulled the belt off and ran it for a little and didn't hear the noise. I put the belt back on and after about a minute or two it started making the noise. It lasted for about 15 minutes so I popped the belt back off and ran it with no noise, popped the belt back on and the noise was there. I'd say with that test that I'm 98% sure that it's something belt-driven, but the fact that noise comes and goes makes me doubt it a little. https://www.youtube.com/watch?v=e5hDstiglGo&list=UUX0XMjuy_U62zvN4XSjLT3Q So there's a link to my videos. Please listen, and if you can't access them let me know so that I can make some settings changes. Thanks.

When I go to the You-tube link all I get is "This channel has no videos".

Same for me...

Thanks guys. I edited the link. https://www.youtube.com/watch?v=e5hDstiglGo&list=UUX0XMjuy_U62zvN4XSjLT3Q

Was your AC engaged? It sounds like a rubbing sound possibly in either the alternator clutch or the AC compressor clutch. It is certainly related to one of the belt driven accessories. Good luck Rob

No, I haven't been running my AC at all.

I would turn on the AC and repeat your check. It could be the AC compressor clutch......

I'll try that.

I've got the same noise. It's not always there and is not apparent as soon as I add any gas. I guess I'll need to experiment on when it's there and when not. 2009 CS manual with sport.

I picked up a stethoscope and just had a listen to everything. The noise transmits through just about everything in there but it definitely loudest at the lower idler pulley. I'm pretty excited that that's probably all it is. Might as well replace all three rollers while I'm in there, right?

Well, I changed all three rollers and was so excited to start up a quite engine and hear this noise. The stethoscope isn't much help in finding it for some reason. The new rollers are definitely quieter than what was on there, and the noise that was coming from the one I deemed bad is now gone. The stethoscope lets me hear a ticking noise from the water pump, but that's not what this sounds like . Right now I'm leaning towards just changing the pump. I once again confirmed that the noise is definitely not there when the belt is off. The noise is present with the AC on and off. The noise seems to be coming from the general area of the water pump but it's hard to be certain. http://youtu.be/mshCIUu4oeo

Ok, move this to "Solved". My water pump just exploded . Thankfully I was almost home.

Just to recap, you did not detect any coolant loss, no rise in temp, no weeping seal on the pump, just that noise? And when it did finally let go, did it just blow out the seal and puke coolant on your driveway? or did the impeller disintegrate? I think I'm starting to hear some noise on my 2006 CS with 70,000miles. Im trying not to make myself paranoid. How many miles did yours have when you had this problem?

If you're hearing the noise, don't wait. Change the pump. And you're correct, I wasn't losing any coolant, no leaks, temps were fine. It started as an intermittent ticking, progressed to a constant rattle, then a loud grinding immediately before it failed and all the coolant ran out. Took about 50 miles for all that to happen if I remember correctly. At failure, the impeller stayed intact but had shifted allowing coolant to bypass it and leak to the outside. I had exactly 45k miles on the car. Haven't had a single problem otherwise or since. If you have any other questions I'm happy to help.

My water pump went out about 2 weeks ago, and that is the exact same sound I heard. I still have the pump and I could go record what it sounds like, to say the least, its the same. The temperature was fine as was the coolant, until it was all over the road.

oops just saw this.

Hey, I had this same exact scenario. A few months ago I began to hear that strange grinding noise, but it was sporadic and I didn't pay it any mind. There was no leakage of anything onto the garage floor or anywhere else that I can recall. I was on a trip that was about 1 hour longer than I normally drive and it was only then that the low coolant light came on. I proceeded down the highway towards the next stop to check it out. Didn't make it. The sound, just like in this video happened, then it overheated and I had to pull off and get a tow. Fluid everywhere, and smoke coming out the sides. I asked Porsche about this and they said it might have been prevented if I had changed the gasket. At any rate the old pump has plastic impellers, which did not break, but the new one has metal impellers.

Thank you! I will call my mechanic monday morning! I'll updade this thread when I know more.

I'm almost positive it's your water pump and it's resonating through the water guide at the bottom right side of the motor. It's the plastic housing down below the A/C pulley. I'm having the same sound and it's very distinct now that I've replaced all the pulley's and tensioner last week. I just had my water pump replaced 20K miles ago under warranty but now that is up. New water pump failing with 20k miles https://www.youtube.com/watch?v=3DpowNdDukw Original water pump failing with 40k miles https://www.youtube.com/watch?v=NTTCRIzVjaE

I want to thank you so much for posting this video! You probably saved me from being stranded on the freeway somewhere, on my way to work, and what would that have cost me? Took her to the shop this morning, (only 3-miles away) amazingly, they had a spot open when I called, (they've been super busy all summer). The mechanic confirmed immediately that the water pump was making its "death-rattle". Should be done by closing time (4:30) but they also added they wont send it out the door without making sure it is all checked. Yeah, it will cost some money, but now I feel obliged to donate to Planet-9 for again saving me from hell. I will post a review of the shop when all is said and done.

Picked up the Cayman S this morning. The Tech commended me on my ability to detect such a subtle indication of water pump failure, which I TOTALLY OWE IT TO THE MEMBERS OF PLANET-9! My noise was more of a steady clatter, almost like a diesel clatter, but not particularly loud. I am in the Great Pacific Northwest, and this time of year, odds are that a failure would have likely happened on the freeway, rush hour, in the dark, in the rain, in the cold, sasquatches... My take-away from this is... Service life of this water pump is about 50,000 YMMV. Keep your cool, don't have thoughts of IMS failure if you keep good maintenance and drive it like a Porsche was meant to be driven. Planet-9 and Pelican Parts have excellent articles on pump replacement. I feel confident that I could do this job if I had the time. Turn the radio off. Know what your Cayman is supposed to sound like, take the time to appreciate the music of your flat-6 even when it is at idle. Took her to Redmond European here in Seattle area. I was lucky to catch them with an open slot to get my car in immediately. Very positive experience. Water Pump was a GEBA $381 said that it had the composite impeller, but when I look at Pelican Parts, the GEBA indicated as metal? (I need to follow up of this, or maybe someone here knows?) Culprit water pump showed no visual wear or play, but did not spin freely as it should. HERE IS THE BREAKDOWN COOLANT 2GAL $87 WATER PUMP $381 GASKET $13 T-STAT $80 (LOWER TEMP RANGE) BELT $53 MISC SHOP SUPPLIES $32 OIL SERVICE/LUBE MOTUL 5W-40 8.2qts $78 FILTER $29 LABOR $725 PCA DISCOUNT 10% The usual service check like tires, brakes, fluids, etc. $1461 out the door. They even gave me an spare quart of the MOTUL 5W-40 She sings now.

That's great you were able to get it taken care of so quickly. You can rest easy now knowing you probably won't have to worry about it again and even if you do it will be a while from now. And you took care of it before it caused a problem. Good job on noticing something wasn't sounding right.