IMS Bearing Question

[tomo]

Yes, have to agree   The oil line on my car is tucked up high out of the way, It has been installed for since 2015 and has been up plenty of bush tracks in my owner ship and not a mark on it.

[Tips]

On 13/03/2022 at 16:51, MFX said:

The tensioners are super simple in a 996 and can be done with the engine in. You need to remove them to change the IMS bearing and all you need to do is lock the crank at top dead centre and lock the cams, then they just unbolt. If you had the correct tools and a hoist you could change them all out in an hour easily.

So by way of update AH finished my car just over a week ago. Double row bearing was on its way and wouldn’t have lasted much longer. 2 of the 3 tensioners were gone so everything replaced.

[Shane911]

21 hours ago, Tips said:

So by way of update AH finished my car just over a week ago. Double row bearing was on its way and wouldn’t have lasted much longer. 2 of the 3 tensioners were gone so everything replaced.

Mmmm I have heard/seen this a few times, just makes me wonder if that is just a stock standard phase that they say to everyone to justify their costs and make the customer feel better about the large amount of money they just spent.  Has anyone ever heard, your bearings were fine and probably would have lasted another 100k kms?  (Yes I work in risk management so don’t take much at face value)

[Tips]

49 minutes ago, Shane911 said:

Mmmm I have heard/seen this a few times, just makes me wonder if that is just a stock standard phase that they say to everyone to justify their costs and make the customer feel better about the large amount of money they just spent.  Has anyone ever heard, your bearings were fine and probably would have lasted another 100k kms?  (Yes I work in risk management so don’t take much at face value)

No wasn’t a sales pitch, I saw the parts and the photos of the old bearing in place before it was removed. My opinion is that on a 22yo car Things wear out and expect that the ims failure probability increases vs back in 1998 the 1% failure on a new engine

[Shane911]

1 hour ago, Tips said:

No wasn’t a sales pitch, I saw the parts and the photos of the old bearing in place before it was removed. My opinion is that on a 22yo car Things wear out and expect that the ims failure probability increases vs back in 1998 the 1% failure on a new engine

Fair enough, thanks for verifying 

[Sherpa]

On 27/03/2022 at 13:17, Tips said:

My opinion is that on a 22yo car Things wear out and expect that the ims failure probability increases vs back in 1998 the 1% failure on a new engine

This is always in my mind when I see the “X% of IMS fail” line rolled out anywhere. Surely it’s a failure rate that has to increase over time through age and wear.
 

But given the amount of preventative IMS swaps and upgrades done by owners, we’ll never have a true sense of the current failure rate at 20+ years.

[TwoHeadsTas]

39 minutes ago, Sherpa said:

This is always in my mind when I see the “X% of IMS fail” line rolled out anywhere. Surely it’s a failure rate that has to increase over time through age and wear.
 

But given the amount of preventative IMS swaps and upgrades done by owners, we’ll never have a true sense of the current failure rate at 20+ years.

Agreed.  I've had 2 cars susceptible to this problem, but given their age now I would be factoring in a replacement when establishing a purchase price.  The problem isn't enough to put me off buying another 996 / 986 if the occasion arose, and I would follow the "be alert but not alarmed" principle I worked with on the other 2 cars (05 987.1 and 02 996.2), and certainly do a replacement, along with RMS if I had to do a clutch change, or my monitoring program detected metal fragments in the filter etc, suggesting an imminent change is required.

[RobCarrera]

Ironically, I was just at EMD automotive having some O2 sensors replaced and had a conversation with Paul about doing the IMS plus all of the associated jobs that go with it. He again recommended the EPS bearing over the LN Engineering solution because of the oil line that can be snagged by road debris. The EPS uses needle bearings which are better suited and runs an oil line from the oil pump. The dodgy IMS is just one of the things that make these cars cheaper to purchase.

[Shane911]

12 minutes ago, RobCarrera said:

Ironically, I was just at EMD automotive having some O2 sensors replaced and had a conversation with Paul about doing the IMS plus all of the associated jobs that go with it. He again recommended the EPS bearing over the LN Engineering solution because of the oil line that can be snagged by road debris. The EPS uses needle bearings which are better suited and runs an oil line from the oil pump. The dodgy IMS is just one of the things that make these cars cheaper to purchase.

Not sure I understand the message here, is EPS just a Bearing replacement? (eg a ceramic bearing )   Also,"The EPS uses needle bearings which are better suited and runs an oil line from the oil pump" So if it runs an oil line from the fuel pump, how is that any different/better than the IMS Solutution?, surely it could get caught on road debris as well?

[Peter M]

2 hours ago, RobCarrera said:

.... He again recommended the EPS bearing over the LN Engineering solution because of the oil line that can be snagged by road debris. 

Rob,
I thought we established on the previous page that was a furphy?

 

2 hours ago, RobCarrera said:

 The EPS uses needle bearings which are better suited and runs an oil line from the oil pump. 

Rob,

Where did you get this assertion from?  I can't think of any modern car that uses needle bearings (EPS's solution is actually more appropriately called a "roller" bearings due to the bearing's roller element diameter to length ratio) for camshafts or camshaft drive.  There is a reason everyone uses plain journal bearings.

From what I can see on the EPS video, EPS supply a slotted oil pump drive that allows pressurised oil from the oil pump to leak into the hollow IMS and escape through their roller bearing at the other end.

I still think the IMS Solution is a better and more permanent solution.

[Peter M]

2 hours ago, RobCarrera said:

 The dodgy IMS is just one of the things that make these cars cheaper to purchase.

I agree.

[Jim45]

2 hours ago, Shane911 said:

Not sure I understand the message here, is EPS just a Bearing replacement? (eg a ceramic bearing )   Also,"The EPS uses needle bearings which are better suited and runs an oil line from the oil pump" So if it runs an oil line from the fuel pump, how is that any different/better than the IMS Solutution?, surely it could get caught on road debris as well?

The EPS replacement does not take its oil feed from an adapted oil filter into the front cover of the bearing. There is a modification done to the oil pump at the other end of the IMS where a hole is punched through to the shaft. One of the gears is notched to allow oil to flow through.

 

[Sherpa]

3 hours ago, RobCarrera said:

He again recommended the EPS bearing over the LN Engineering solution because of the oil line that can be snagged by road debris.

I’ve got the solution on my car and spent enough time under it to say: if that hose gets “snagged” you’ve got bigger issues to worry about. You’ve probably lost your sump and probably some chassis components…

If you’re building a safari or going off-road, maybe it’ll be a problem…

[WB997.2GTS]

2 hours ago, Peter M said:

Rob,
I thought we established on the previous page that was a furphy?

 

Rob,

Where did you get this assertion from?  I can't think of any modern car that uses needle bearings (EPS's solution is actually more appropriately called a "roller" bearings due to the bearing's roller element diameter to length ratio) for camshafts or camshaft drive.  There is a reason everyone uses plain journal bearings.

From what I can see on the EPS video, EPS supply a slotted oil pump drive that allows pressurised oil from the oil pump to leak into the hollow IMS and escape through their roller bearing at the other end.

I still think the IMS Solution is a better and more permanent solution.

Peter, you explained the EPS mod perfectly. I did the EPS modification to my 987 Boxster when I pulled the engine down to replace a spun main bearing.

The only modification to the pump is the drive pin and takes around an hour to do. Remove pump, remove drive pin which is driven by the intermediate shaft, punch hole into shaft (tool supplied with the kit) install new drive pin which has a V ground the length of the pin, refit pump. Its easy, only problem is you need to dismantle the engine to get to the bearing if its larger than the access hole. EPS also have a custom boring tool that allows you bore the casing to remove the bearing. 

 

[Carrera28]

3 hours ago, Sherpa said:

I’ve got the solution on my car and spent enough time under it to say: if that hose gets “snagged” you’ve got bigger issues to worry about. You’ve probably lost your sump and probably some chassis components…

If you’re building a safari or going off-road, maybe it’ll be a problem…

Plus you can buy a sump guard to cover the area which provides protection and reduces the chance of snagging.

If you have a lowered car with the enlarged sump I can highly recommend the LN Engineering Sump Guard as a good bit of kit to both prevent snagging and to prevent cracking the sump.

[Peter M]

I see Mechanic Jack has created his own IMS bearing "solution":

Facebook

 

[911CSR]

37 minutes ago, Peter M said:

I see Mechanic Jack has created his own IMS bearing "solution":

Facebook

 

I'm not sure the torque rating on that is high enough...