Intermediate shaft?

[superman_006]

Well my 99' 996 C2 has about 42k on it. when I first got it about 2 years ago it sounded like it had rattle in the muffler. Its worse now, it starting to sound like my old 914. I have been online searching into the motor noises..... and everything sounds like the intermediate shaft but mine sounds like its comming from the front of the engine (rear of the car) . So I am not sure if its this shaft or an acc pully. In a lot of the articals.....people are talking about removing some cover. Is this with the motor in? I have also seen a bunch of pics with bolts broke off, but all those pics are super close. Does this shaft stick out both ends of the engine? Do I have to pull the engine out to replace the bearing?

My climate control also started bleeding and on the DIY section, they have a link for just the LCD but its a bad link. Anyone got a new link?

[superman_006]

Well after searching more..... Its looking like a trans pull, then pull the clutch and flywheel. Are these IMS bearing "upgrades".... really upgrades? If so which ones are the best ones?

[txhokie4life]

Well after searching more..... Its looking like a trans pull, then pull the clutch and flywheel. Are these IMS bearing "upgrades".... really upgrades? If so which ones are the best ones?

Yes -- and I strongly recommend the LN Engineering one. I use it on all my engines.

Mike

[fpb111]

It is very unlikely that a IMS would take over two years after starting to rattle to fail, more likely two seconds. Before you pull the trans, pull the "fan" belt run the engine for 20 seconds and see if the noise goes away. If so check the idler pulley and start looking at the belt driven accessories.

Get a rubber mallet and tap the mufflers to see if the rattle noise is there.

[superman_006]

Ive only put 800 - 1000 miles on it since I got it. I have beaten on the exhaust with the car off and it up in the air. I am going to video it and try to post it on here to see what you all think. It does sound more like a waterpump or an idler pully to me. I also counldt feel the noise anywhere on the engine or any other the acc i could touch

[swynn97]

Agreed on checking the exhaust. This is very likely a catalytic convertor issue and will be zero cost to replace given your mileage. I had a similar issue and got a free engine out of Porsche prior to them figuring out the issue was really the cats.

Any kind of inspection of the engine internals requires dropping the engine and opening it up - about a $1200'ish cost. Good luck.

Simon

[superman_006]

OK... Well I took the air box out and ran the engine for a few mins..... I could feel the noise most when i put my finger on the bolt for the lowest idler pully. I took the belt off and NO noise. I turn all of the pullyes by and and they feel fine.

Are these bearings "serviceable"? I took both the idler pullyes off and they messure out ther same, one bearing says s-74 and the other says s-79 (i think). I went to a local bearing distributor and bought 2 for about $7 that have the same ID and OD as the factory bearings however the thickness is about 4mm thinner. The guy there seemed to belive that the bearings he sold me would definatly work and they have a 1 year warrant.

I can spin the OEM pullly in my hand and it doesnt seem to make any noises and feels smooth, so Im not 100% sure yet.

Edited June 9, 2011 by superman_006

[fpb111]

Put the bearing(s) in and try it again.

Also Check your water pump for play & noise

[txhokie4life]

Might spin fine in hand,

But under load (with the belt tensioned), the bearing maybe dragging on the pulley bolt.

I had one that seemed fine - then seized and snapped the bolt clean off.

In hindsight -- I might have heard something prior to failure -- but it was not obvious enough to take notice at the time.

Mike

[superman_006]

Well the thinner bearing wont work... the inner shaft has a shoulder on it that the same thickness as the bearing.... Its so it secures the inner race of the bearing. It still makes the noise and I am starting to think its the water pump. When I spin the water pump by hand it doesnt make any noise, It doesnt seem to have much play in the shaft. I took some videos of the engine running with/ without the belt on. You should be able to click on the pic and the video will pop up

[goldenwarrior1]

If you don't have a stethoscope take a very long screw driver and place it lightly on each rotating pulley and then placing your ear to the handle of the screw driver while it is running . You will be able to tell immediately which one is making the noise as the sound will travel up the screwdriver. My guess from listening to the video is the water pump or perhaps the a/c compressor bearings. Not much else left.

[superman_006]

Well, Once I got this waterpump off I knew for sure this was it. I put a new one on in about an hour........ Sounds great!!! Thanks guys