IMS bearing question
 

Dear All,

As mentioned in my introduction earlier, I bought a '99 Boxster with an alleged IMS bearing failure and therefore a need for a replacement engine. I bought the car with an intent to fix the engine. This is where I am at now (the failure was caused by a broken variocam pad that I found in pieces all over the engine): http://986forum.com/forums/uploads02...1541090585.jpg

My question regards to theIMS bearing. This car has 100k miles on it, and the original dual-row bearing does not show any sign of wear (dust cover removed):

http://986forum.com/forums/uploads02...1541090701.jpg

Would you guys replace this?
Also, I bumped into this mod using a slotted hex key that diverts the oil flow and gets pressurized oil from the pump to the IMS bearing. Any experience, thoughts about this?

eBay

Thanks!

IMO, if you're that far into the engine already... why not do it? Could do the IMS Solution and put that issue to bed permanently.

Yep to replacing the bearing and no to any of the eBay products. Full Disclosure is that when my clutch wore out my dual row was replaced with a LN Product.

Punching a "precise" diameter hole with a center punch so that if floods the entire IMS shaft with oil? And then replacing the already weak oil drive shaft with one that has a slot ground in it? In a word: No.

+ 1 On the IMS Solution, do it once and do it right.. :)

Thanks for all the input! Is there a tendency for the hexagonal oil pump driver to break? I haven`t heard of such an issue with these engines. Other than that, delivering a small amount of fresh oil through the IMS sounds reasonable to me.

I wouldn't screw around with a controversial "fix". Just put a ceramic coated LNE bearing and be done with it.

That is what I did when I replaced my clutch.

The hex shaft is a well known failure point.

The concept of spraying oil on the factory bearing is grossly oversold. While a little oil is good, a lot is not necessarily better, particularly if the shaft gets flooded, either because it was used as an oil conduit, or because too much oil is sprayed into the bearing and the factory rear bearing seal won't hold it. If you look at the IMS Solution, the kit puts a pressed in plug behind the solid bearing specifically to prevent this.

You can actually get sufficient oil into the factory bearing by just removing the rear bearing seal and letting the oil mist inside the engine do the job.

I would put a new sealed double row bearing in. Nothing fancy. Just a very good quality one. No need for fancy stuff imho. Most important is, that it is installed correctly which shouldn't be a problem when the engine is disassembled. Also take a very good look at the rod and "cover" that holds the bearing in place. Especially the rod can be improved.

Well, whatever had been put into the bearing as a lubricant, was replaced by engine oil long ago. So it clearly seems to be a good idea to just remove the rear bearing seal on the new bearing I`ll put in.

Just a thought...

If you had metal pieces circulating in the engine, then stay away from any open seal ball bearing solution. IMHO, that's just asking for failure if a metal piece gets between the races and the balls

Clean the engine completely and put in an IMS Solution

What metal pieces?

Unless you want to drop thou$ands on overpriced LNE products, go with a replacement double row or roller bearing.
If it were me, I'd go with the EPS roller. Since it's already apart, I would not keep the old bearing in.

There is no proof that the LN solution is "permanent" or incapable of failure, and there are plenty reports of their other bearings failing, so it's really just a matter of which you feel the most comfortable with. There is no correct answer. ;)

.

First, I wrote 'if'' purposely b/c only the poster knows if there were metal pieces circulating in the engine

Second, the IMS Solution doesn't cost thousands.

Third, the failure mode of any bearing other than a plain bearing is that a failure will severely damage the inside of the engine. The Solution is the safest bet either from a cost or hours of labor.

1) He didn't mention any metal, only a failed variocam pad. No need to make assumptions.

2) Yes, it does. $1,849 plus tax and shipping. If you want any warranty coverage, you'll need installation from a certified installer which will bump that to $4k-$5k.

3) Plain bearings have their own modes of catastrophic failure. Take it from an engineer. ;)

As I said, the best course is for the OP to do the research and select the one he's most comfortable with. That's always the best advice.

Agreed
 

Nothing is permanent, especially if it moves

Does this board have a popcorn eating emoji?

I don't know how many "The Solution" bearings have been installed but I also haven't seen any failure reports on the 10 Porsche forums I frequent.

When reading postings about IMS bearing replacement kits, you must understand that there are several groups that seem to have great animosity toward one supplier or another. Makes the political ads seem tame by comparison.

If I were selecting a bearing kit for replacement, I'd think about how I'd use the car, how much else I was investing in preventative maintenance, what other potential problem areas the same amount of money might fix, what the experience of the installer was with a specific product and even why I wasn't buying a completely rebuilt engine.

As an example, why am I focusing on the IMS as opposed to the suspension, a complete heads rebuild, or whatever?

How much to spend on PM is such a subjective choice.

Spending $3,000 on a permanent bearing "solution" on a car worth $5,000 in perfect running order is a little stupid too.

Replace it with an OEM bearing. Send it. Done.

Wow, after so may years, this IMS bearing issue seems to be a debated question :) Considering the original dual row bearing looks perfect after 100000 miles I think I`m just gonna replace the bearing to an original or similar dual row bearing. Any idea where such a bearing can be purchased?

Which oil you going to run?

The original bearing and its associated mounting contains several failure causes, not just the one caused by bearing wear. Look at the description of some of the kits to get hints of which components they have found it wise to upgrade.

There are widely circulating instructions on how to replace an IMS bearing that are wrong. Beware.

Consider the cost and time to acquire a complete set of (or to make) tools. There are specialized tools recommended. Sometimes you can rent them for one time use.

Or if you're handy: Build your own. Once you SEE the tools, you realize how simple they are.

Did you guys look at the pictures in his post that clearly shows the IM shaft and bearing in his hands? Specialized tools, instructions???? But yes new bolt and cover would be a good choice.

I`m so far from that stage that I haven`t even thought about it. Why are you asking?

For the reassembly, is there a real service manual available for the engine? I bought the Bentley workshop manual as that was the most recommended, but basically it says not much about the engine. I will need torque settings, timing chain instructions, etc..

Just playing around, Because oil discussions get as confusing as IMSB discussions.

That information was never published by Porsche. Jake Raby published books on the subject.

Your original question was asking if anyone had experience with replacement bearing kits. I installed the EPS IMS kit in my 1997 Boxster about 3 years and 35K miles ago. I have not had the first problem with it and the peace of mind knowing it is not going to be a problem releases me to enjoy driving the heck out of my Boxster.

Thanks Bob. That was exactly what I was looking for as I am mulling the variety of options. Short, factual with no malice towards others.

I have not been on the board long, but when I bought my first boxster the IMS paranoia drove me to read a lot on the question. The result of all that reading was that I am no longer paranoid and I don't feel it is necessary to immediately tear my cars apart to replace the IMSB. The clutch on my Blue Boxster feels tired so I am seriously considering doing the clutch and IMSB on it this winter while I am getting the maintenance up to date.

I was impressed by the videos made by Ben Burner on the IMS. He sourced the bearing and other parts himself, built his own tools and did a whole series of videos that go from the choice of bearing, tear-down and reassembly and cost breakdown. I like the way he approached the problem and will probably follow his example. This video explains his choice of bearing:
https://www.youtube.com/watch?v=IxdvSq_byZw

Now just give me a minute to hide behind a brick wall...

Hilarious!

Safe place until a grenade gets lobbed over the wall!

Words are cheap There's theory (opinions). There's reality (statistically verifiable failure rates from actual installations). They are not the same!

So ask the various IMS suppliers how many of their units have been installed. Ask what their failure rates are? If they won't or can't provide you with statistically reliable numbers, they are just talking theory.

Theory is great. Just know when you put an IMS in your car, then theory turns into an experiment, which may or may not work out. And if the experiment fails, it will cost you thousands to remedy.

I like this guy, he spent a considerable time on this matter. I saw another video from him in which he cut a bunch of IMSBs apart and looked into them. I agree with him, it`s ridiculous how much these "solutions" cost for a car that`s worth not more than 5k. I have read numerous articles on the web on replacing the IMSB and the original two-row bearing that was replaced was in nearly perfect condition.

I liked the youtube video, I saw another one from him where he cuts IMS bearings apart and looks into them, that`s a good one, too. I`ve seen many reports on the web about replacing the original IMSB that was otherwise in perfect condition, especially the dual row ones. The original ones apparently last for 100k miles at least, and afterward when they get replaced to a new one, those cars are still running within the next 100k miles probably (or at least cars over 200k miles are rare), so there`s no way to really tell if any kind of IMSB upgrade is better that the original 2 row bearing, which cots like $50. And I agree, creating hysteria and selling "the solution" for $800 for cars worth 5k is just not cool. IMHO.

I went to a homeowners' association meeting the other day and they were still discussing the same issues that were being discussed 7 years ago. With no more expertise or research applied to the subjects.

The hysteria arises because 1) the timing of IMS bearing failures is extremely difficult to predict and the 2) cost of failures is unreasonably high given the market value of these cars.

Data suggests the following failure mechanism is the most likely. IMS bearing seals degrade and allow the internal lubricant to wash out. Unfortunately, the leakage is too small/slow to allow mist engine oil to replace the loss. When this happens, the resulting friction increase leads bearing spallation, which then leads bearing failure.

Timing is hard to predict because contaminants in the oil of low mileage cars that sit idle for long periods accelerate seal degradation. High mileage cars, typically daily drivers that get up to operating temperature frequently, slow seal degradation markedly. Hence, IMS failure occur in both low and high mileage cars. There is no magic number after which these cars are safe.

Single row bearings fail more frequently than dual row bearings because they are more highly loaded and they see the effects of poor lubrication more dramatically.

People can increase their odds of avoiding an IMS bearing failure when they replace the original by taking the following steps:
1) install a bearing that can withstand higher loads, e.g. ceramic over steel, dual over single, etc.
2) ensure that the bearing receives adequate lubrication, e.g. is unsealed so it receives mist oil or is oil fed

In my case, I installed the IMS solution because it was capable of bearing the highest loads, was oil fed, and if it did fail it was the one design that was most likely to keep the engine from jumping timing.

OK, thinking "Experimental" - has anyone removed their 2 row and after finding nothing wrong, simply stuck it back in?

Not sure it`s a good idea to remove a bearing and place it back in since the axial force used to pull it out from the shaft may cause detoriation leadng to premature wear. Once you remove it by forcing it out by prassing the inner ring axially you better replace it to a new one.
My IMS was full with engine oil, and I read the same in all of the reports of bearing replacement. In my understanding filling the shaft with oil can only occur from the flywheel side through the bearing, if the pump side is not punched through. So in all these cars the bearing lost its original lubricant long ago and was washed out with engine oil. My impression is that, as the IMS sits on the bottom of the engine, it`s close to the oil level in the sump so it can get excessive oil by splashing. This may be sufficient if you remove the seal and keep the oil level close to maximum. I`ll look more into this next weekend since now the engine cases are apart.

That would probably be fatal. During the extraction process, the balls, cages and rear race are subjected to extreme loading forces, distorting finished surfaces and pretty much destroying the cages. The center bolt is also subjected to loads it was never designed for as well.

Maybe just buy the cheaper Porsche bearing and plan to make it a maintenance thing with clutch jobs? Is it worth more to put in a more expensive bearing? Who knows at the end of the day. If it were me, and I were rebuilding the engine anyway, I'd probably go all in and do the Solution and be done with it. Simply because you are there, and trying to justify cost vs value is pretty pointless as rebuilding the engine takes that discussion right off the table.