Very loud humming

[996Tomek]

Greetings All,

I think I landed on the best Porsche forum on the web and I feel privliged for being able to post here.

The problem:

I'm looking into buying a '00 Carrera, which was originally bought in Canada. The car has a new engine and clutch w/ about 10k miles on it. When I went to test drive the car, right away I noticed a VERY LOUD humming noise coming from the back. It is there no matter what speed and it gets louder the faster you go.

When I turned the steering wheel sharply to the left, the noise went away. As I straightened out the wheels, the noise came back.

The car is being sold for a highly discounted price, very likely b/c of this noise that scares buyers away. My question is: what can most likely be the cause of this issue? Is my gut feeling right, that it's the wheel bearing since the noise goes away when you turn? Also, if it is the bearing; can any mechanic fix this or do I have to take it to Porsche to get it fixed? Unfortunately the car is not local, so I can't park it in my driveway while I'm searching around for ways to fix it.

I'd greatly appreciate the advice and a quick response. I'm looking forward to being a proud owner of a 996 Carrera, as well as a valuable member of this forum.

Regards,

Tomasz.

[etwd]

rear wheel bearing. Common when the car is abused (burnouts, donuts) Cheap fix. Hopefully the spider gears are in tact. PPI immediately!!!!!!!!

Tomasz.

[phillipj]

I can't help you with the cause of the noise but I can tell you that you need to have the car inspected by a Porsche tech before purchase.

Is the engine a "reman" from Porsche? Who did the install? Does the seller have the documentation? In order to get the 2 year warranty it would have had to be done by a dealer.

Even if you are getting a "good price" you have to know that these cars can get very expensive to fix.

There are many, many good cars out there right now and it's a buyers market. Be patient and look around. Might be a good idea to walk away from a "mystery noise" :o

Unless of course a Porsche mechanic will tell you wat the noise is and how much it will cost to fix.

Have an inspection and don't buy the car without service and repair records.

Trust me on this one... :D

[996Tomek]

I can't help you with the cause of the noise but I can tell you that you need to have the car inspected by a Porsche tech before purchase.

Is the engine a "reman" from Porsche? Who did the install? Does the seller have the documentation? In order to get the 2 year warranty it would have had to be done by a dealer.

Even if you are getting a "good price" you have to know that these cars can get very expensive to fix.

There are many, many good cars out there right now and it's a buyers market. Be patient and look around. Might be a good idea to walk away from a "mystery noise" :o

Unless of course a Porsche mechanic will tell you wat the noise is and how much it will cost to fix.

Have an inspection and don't buy the car without service and repair records.

Trust me on this one... :D

Thanks a bunch for fast response. From what I know, the car had the engine installed by a 3rd party shop, not an authorized Porsche dealer. The engine did come from Germany as a new engine. What I also found out when I visited the shop that installed the engine and the clutch, is that one of the rear wheels was slightly bent but it did balance. My guess is that the wheel was never fixed and after 10,000 miles the rear bearing just quit from all the vibration.

If I do get the car I'd have to drive it from FL to IL, so I need to be certain that my wheels are going to turn! Hopefully it's just a bearing...

Tomasz.

[Dharn55]

I had the rear wheel bearings reploaced under warranty in my 2000 996 with only about 20,000 miles, had a humming in the rear and the dealer said they were bad. The cost was over $2,000 because the dealer said he had to pull the wheel carier to press out the bearings. I don't know if this is really required and did not care at the time is the warranty paid for 100% of the cost. But it did seem like alot of money.

[996Tomek]

I had the rear wheel bearings reploaced under warranty in my 2000 996 with only about 20,000 miles, had a humming in the rear and the dealer said they were bad. The cost was over $2,000 because the dealer said he had to pull the wheel carier to press out the bearings. I don't know if this is really required and did not care at the time is the warranty paid for 100% of the cost. But it did seem like alot of money.

That is a lot for wheel bearings' replacement. Hopefully this one won't be as bad. Thanks for the reply.

[PorschePRH]

I had the rear wheel bearings reploaced under warranty in my 2000 996 with only about 20,000 miles, had a humming in the rear and the dealer said they were bad. The cost was over $2,000 because the dealer said he had to pull the wheel carier to press out the bearings. I don't know if this is really required and did not care at the time is the warranty paid for 100% of the cost. But it did seem like alot of money.

That is a lot for wheel bearings' replacement. Hopefully this one won't be as bad. Thanks for the reply.

I had an indy shop quote $650 per bearing. They and others have suggested that you need to replace both sides at a time to keep the friction levels the same left to right.

If your shop needs to remove the wheel carrier to press out the bearing, what they are saying is they don't have the right tools and/or know how to do the job and they just plan to pass the cost on to you.

There are specialty tools for doing it without disassembling the whole thing. And the tools aren't too expensive for them ($200-$300 for the tool). The bearings are huge and therefore around $100 per wheel bearing. There are several DIY articles on here about this topic.