"dry bearing noise" coming from top....
07-08-2014, 06:09 PM
#16
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Thread Starter
Macster, I have what I believe is the same issue with whine coming from behind the airbox. I have been told it is likely one of the tensioners or idler roller bearings. I am also told it is a complete engine out to fix the problem (8 hours of OPC labour to boot). What was the method employed for your fix?
Good grief.
The job is a bit fiddly to do as the rear bumper cover has to come off and the air box and maybe some other things but it is not an engine out job unless the shop owner needs to make a boat payment...
The one I posted about back in 2010 was covered by the car's CPO warranty.
I had another idler roller bearing go out more recently -- within the last 6 months? -- and had all idlers replaced along with the tensioner oh and the belt. I do not recall the cost. I had some other things taken care of at the same time, too.
The job is pricey compared to say doing this for my Boxster. The parts are not cheap and as I touched up above there is some work to get things cleared out of the way. Roughly I would think $1000 would cover what I had done, which I had done at a dealer service department. An indy? Who knows?
07-09-2014, 11:54 AM
#18
Burning Brakes
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I had the airbox off today and tried WD40 on everything. Nothing changed unfortunately, without any level of expertise, the sound seems more to the right (as you look at the engine), near the aircon compressor than the middle where the rollers are. I can ask them to look at this first, could reservoir or pump?
07-09-2014, 02:13 PM
#20
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Thread Starter
I had the airbox off today and tried WD40 on everything. Nothing changed unfortunately, without any level of expertise, the sound seems more to the right (as you look at the engine), near the aircon compressor than the middle where the rollers are. I can ask them to look at this first, could reservoir or pump?
The first failed idler had me and others guessing the power steering pump as it was coming from that area but it proved to be the idler right next to it.
I'm not sure how the tech made the diagnosis but he nailed it cause just the idler roller was replaced and the noise was gone.
The 2nd time I just had the tech replace all idlers and the tensioner.
You're going to have to get your hands dirty and remove stuff to expose that region of the engine and remove the belt and go around and check each idler roller and tensioner roller and each accessory drive to any signs of looseness/play or seal (and bearing) degradation.
If you want to eliminate the possibility the noise is not coming from something related to the accessory drive you can remove the belt and start and run the engine a while, a moment or two (well longer but better to err on the side of caution. I've driven my Boxster a couple of blocks with no water in the engine but the engine was cold.). This requires the noise be present when the engine is cold.
You can start and run a hot engine with no belt but I would limit the running to just seconds and I would allow the engine to cool down from its nominal operating temperature as much as it could and still manifest the noise.
Or you're going to have to get the noise going and give a good listen with a mechanic's stethoscope to pinpoint the source of the noise. This I think should be left to the tech though as if you get the stethoscope caught in belt it can add to problems.
07-09-2014, 08:03 PM
#22
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Do not use WD40 or anything else on the belt.
The first failed idler had me and others guessing the power steering pump as it was coming from that area but it proved to be the idler right next to it.
I'm not sure how the tech made the diagnosis but he nailed it cause just the idler roller was replaced and the noise was gone.
The 2nd time I just had the tech replace all idlers and the tensioner.
You're going to have to get your hands dirty and remove stuff to expose that region of the engine and remove the belt and go around and check each idler roller and tensioner roller and each accessory drive to any signs of looseness/play or seal (and bearing) degradation.
If you want to eliminate the possibility the noise is not coming from something related to the accessory drive you can remove the belt and start and run the engine a while, a moment or two (well longer but better to err on the side of caution. I've driven my Boxster a couple of blocks with no water in the engine but the engine was cold.). This requires the noise be present when the engine is cold.
You can start and run a hot engine with no belt but I would limit the running to just seconds and I would allow the engine to cool down from its nominal operating temperature as much as it could and still manifest the noise.
Or you're going to have to get the noise going and give a good listen with a mechanic's stethoscope to pinpoint the source of the noise. This I think should be left to the tech though as if you get the stethoscope caught in belt it can add to problems.
The first failed idler had me and others guessing the power steering pump as it was coming from that area but it proved to be the idler right next to it.
I'm not sure how the tech made the diagnosis but he nailed it cause just the idler roller was replaced and the noise was gone.
The 2nd time I just had the tech replace all idlers and the tensioner.
You're going to have to get your hands dirty and remove stuff to expose that region of the engine and remove the belt and go around and check each idler roller and tensioner roller and each accessory drive to any signs of looseness/play or seal (and bearing) degradation.
If you want to eliminate the possibility the noise is not coming from something related to the accessory drive you can remove the belt and start and run the engine a while, a moment or two (well longer but better to err on the side of caution. I've driven my Boxster a couple of blocks with no water in the engine but the engine was cold.). This requires the noise be present when the engine is cold.
You can start and run a hot engine with no belt but I would limit the running to just seconds and I would allow the engine to cool down from its nominal operating temperature as much as it could and still manifest the noise.
Or you're going to have to get the noise going and give a good listen with a mechanic's stethoscope to pinpoint the source of the noise. This I think should be left to the tech though as if you get the stethoscope caught in belt it can add to problems.
The WD40 test is common practice at near every workshop in the world. It will not damage the belt or any part of the engine and it's effects disappear in seconds. Have you ever heard of belt dressing? Guess what one of the ingredients is? Yes, silicone. In the old days they used to use soap.
07-09-2014, 08:18 PM
#23
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I had the airbox off today and tried WD40 on everything. Nothing changed unfortunately, without any level of expertise, the sound seems more to the right (as you look at the engine), near the aircon compressor than the middle where the rollers are. I can ask them to look at this first, could reservoir or pump?
07-10-2014, 11:02 AM
#25
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https://www.dropbox.com/s/g1niwaxp32w1gcm/Noise.m4v
I have also had a fuel pump make a similar noise but that sound comes from the front of the car.
If your whine is varying with RPM that usually means a bad roller or pulley or possibly something wrong with the clutch on the AC compressor pulley.
If you are feeling adventurous you could buy a stethoscope from an auto parts store for $10 and try poking around with it while you work the throttle linkage on the engine.
Last edited by Carlo_Carrera; 07-10-2014 at 04:12 PM.
07-10-2014, 03:29 PM
#26
Race Director
Thread Starter
It is best to never purposely run an engine without a belt on. Never.
The WD40 test is common practice at near every SHADE TREE in the world. It will not damage the belt or any part of the engine and it's effects disappear in seconds. Have you ever heard of belt dressing? Guess what one of the ingredients is? Yes, silicone. In the old days they used to use soap.
The WD40 test is common practice at near every SHADE TREE in the world. It will not damage the belt or any part of the engine and it's effects disappear in seconds. Have you ever heard of belt dressing? Guess what one of the ingredients is? Yes, silicone. In the old days they used to use soap.
The last belts I ever used dressing on were leather, the leather link belts used to drive optical machinery the was built before the war, WWII that is.
There is no need to use belt dressing for modern belt drives.
Uncounted owners (including me) have run countless belts their nominal service life (and sometimes longer than that) and never had one fail nor need any belt dressing for any reason at all. Applying belt dressing, or WD40, is what you do when you don't know what to do.
The WD40 attacks the rubber and acts to retain dirt. It should not be used.
OTOH, the belt removal trick to determine if the noise is coming from the accessory drive system or is internal to the engine is a common "test" used by every auto repair shop worthy of the name.
07-10-2014, 04:11 PM
#27
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FIFY.
The last belts I ever used dressing on were leather, the leather link belts used to drive optical machinery the was built before the war, WWII that is.
There is no need to use belt dressing for modern belt drives.
Uncounted owners (including me) have run countless belts their nominal service life (and sometimes longer than that) and never had one fail nor need any belt dressing for any reason at all. Applying belt dressing, or WD40, is what you do when you don't know what to do.
The WD40 attacks the rubber and acts to retain dirt. It should not be used.
OTOH, the belt removal trick to determine if the noise is coming from the accessory drive system or is internal to the engine is a common "test" used by every auto repair shop worthy of the name.
The last belts I ever used dressing on were leather, the leather link belts used to drive optical machinery the was built before the war, WWII that is.
There is no need to use belt dressing for modern belt drives.
Uncounted owners (including me) have run countless belts their nominal service life (and sometimes longer than that) and never had one fail nor need any belt dressing for any reason at all. Applying belt dressing, or WD40, is what you do when you don't know what to do.
The WD40 attacks the rubber and acts to retain dirt. It should not be used.
OTOH, the belt removal trick to determine if the noise is coming from the accessory drive system or is internal to the engine is a common "test" used by every auto repair shop worthy of the name.
WD40 does not attack the rubber in any way nor will it cause it to attract dirt. What it does do is repel moisture and breakup glazing on the belt caused by moisture absorption. Moisture is the number one cause of belt squealing and whining. A shot of WD40 will tell you instantly if a belt is the cause of a squeal.
As for running a modern car with a modern ECU, sensors and electrical system without a belt, some shops may do it (I would never use a shop admitting to doing it) but if someone tries it at home they could be barraged with countless fault codes and a check engine light. Some codes they will not be able to clear with just a simple ODB2 reader. Running a 996TT without a belt means an almost guaranteed trip to mechanic with a Porsche diagnostic computer.
07-11-2014, 10:07 AM
#28
Burning Brakes
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listening to this file, it definately does not sound like this. I should have a go at rigging up my go pro over the weekend and creating a similar sound file for you chaps to have a listen too. Perhaps someone will recognise it immediately.
The power steering pump whine tends to not vary with RPM and sounds like this.
https://www.dropbox.com/s/g1niwaxp32w1gcm/Noise.m4v
I have also had a fuel pump make a similar noise but that sound comes from the front of the car.
If your whine is varying with RPM that usually means a bad roller or pulley or possibly something wrong with the clutch on the AC compressor pulley.
If you are feeling adventurous you could buy a stethoscope from an auto parts store for $10 and try poking around with it while you work the throttle linkage on the engine.
https://www.dropbox.com/s/g1niwaxp32w1gcm/Noise.m4v
I have also had a fuel pump make a similar noise but that sound comes from the front of the car.
If your whine is varying with RPM that usually means a bad roller or pulley or possibly something wrong with the clutch on the AC compressor pulley.
If you are feeling adventurous you could buy a stethoscope from an auto parts store for $10 and try poking around with it while you work the throttle linkage on the engine.
08-23-2014, 05:01 AM
#29
Burning Brakes
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sorry for the slow feedback folks, holidays and work travel have kept me busy. The fault was indeed the idle roller, replaced with engine in car. Car now sounds much improved. I also had a steering arm replaced, tightened up the feel, refurbished hollow spokes and new pirelli p zeros. All in around $3000. They even took it to the local testing station for me and got all my paperwork in order. Finally a local isn OPC that do a good job t a good price. Bonus points, as it is over the border in Germany, I get my VAT back and now have this on account at the OPC. What can I spend $500 on!!!!
Thanks to all for the feedback and support, at a time I was sweating over a major engine out bill.
Steve
Thanks to all for the feedback and support, at a time I was sweating over a major engine out bill.
Steve
08-23-2014, 04:05 PM
#30
Macsters, over the years you have provided a wealth of technical advice here. I have personally benefitted from it and I thank you for it but when comes to actual down and dirty hands on mechanics you are slightly out of your element.
WD40 does not attack the rubber in any way nor will it cause it to attract dirt. What it does do is repel moisture and breakup glazing on the belt caused by moisture absorption. Moisture is the number one cause of belt squealing and whining. A shot of WD40 will tell you instantly if a belt is the cause of a squeal.
As for running a modern car with a modern ECU, sensors and electrical system without a belt, some shops may do it (I would never use a shop admitting to doing it) but if someone tries it at home they could be barraged with countless fault codes and a check engine light. Some codes they will not be able to clear with just a simple ODB2 reader. Running a 996TT without a belt means an almost guaranteed trip to mechanic with a Porsche diagnostic computer.
WD40 does not attack the rubber in any way nor will it cause it to attract dirt. What it does do is repel moisture and breakup glazing on the belt caused by moisture absorption. Moisture is the number one cause of belt squealing and whining. A shot of WD40 will tell you instantly if a belt is the cause of a squeal.
As for running a modern car with a modern ECU, sensors and electrical system without a belt, some shops may do it (I would never use a shop admitting to doing it) but if someone tries it at home they could be barraged with countless fault codes and a check engine light. Some codes they will not be able to clear with just a simple ODB2 reader. Running a 996TT without a belt means an almost guaranteed trip to mechanic with a Porsche diagnostic computer.
There is no harm in doing so either... the only thing that would even remotely effect any electrical system is the fact that the battery wouldn't be getting charged for the 2 minutes you took the belt off to do a diag, and I know for a fact you can run a 911 turbo on a fully charged battery and no alternernator for at least 30 min! (been there done that when alt failed) .. and on a cold engine it would not harm the engine in any way if no coolant was running thru it. I don't know how you think it would trigger a myriad of fault codes, but it wouldn't and hasn't in any car for me in the past to run them without a belt for a couple of mins.
