Should I or shouldn't I?
 

I think I know the answer, but I have my '98 in for a new clutch and need to decide if I need to add an IMS bearing to the work order. The independent shop I take it to is saying it's not necessary. I am torn. I bought this as an inexpensive car for fun and as a project to work on with my son. I have already spent a lot on much deferred maintenance and have replaced the entire suspension. I find it a little hard to justify the expense. I see in the stats that the dual row '98 bearings have a much lower failure rate than the later designs and I could rationalize the gamble. I know this has been discussed a million times, but I thank you for any thoughts.

Get it done. Yes, the dual-row bearings are much less likely to fail. And depending on the history of your car (has it been run consistently without long storage periods? has it been maintained regularly?) it may not be an issue that ever has a real chance of arising.
However, once you have the transmission out, the rest of the labor/parts for the IMSB swap is not all that much.
Additionally, if you ever sell your Porsche, we all know the first question any buyer is going to ask.

Absolutely not.

The failure rate on the dual row is so low, you are much more likely to lose the engine another way.
Don’t give into the scaredy crowd, like “Fiddlebog”.

I'm with PW here. Yes, it could happen. Or you could have a rod bolt failure, spun bearing, or a myriad of other things that could happen to any engine. Change your oil. Drive it. :cheers:

I just put a used '03 motor in my car, with 86k miles on it. I did NOT replace the IMS bearing. I just refuse to drink the koolaid, and succumb to the hysteria.

Fiddlebog, if a buyer passes on my car because the IMS isn't done, I don't want to sell to the anyway, because that personality will come see me to make good on any minor problem the car has fit the next 90 days. Not a buyer I want anything to do with.

Sent from my SM-G970U using Tapatalk

I will note that I have not done the IMS on either of my Boxsters, nor do I intend to go out of my way to do so.
I also haven't had the need to drop the transmission, though.

Only you can answer this question.

How will you feel if the IMS fails? How will you feel if after doing the IMS it fails for another reason? Do you have enough cash to replace the IMS? The motor?

THIS question is the one which drove my decision NOT to replace the IMS this time.

Last motor, i took out a perfectly good bearing with 147k miles on it, and replaced it. 5000 miles later I lost the motor to something entirely unrelated.

How many "what-ifs" can I defend against? Where do I draw the line? I buy a 15-20yr-old car, with lots of miles, with unknown service history (sure, you may think documentation tells the story, but it's still a "box of chocolates").. there are literally DOZENS of things that are at least as likely (from a sheer statistical point of view) to take-out this car as the IMS is.

pi$$ on it. I left this one alone.

Wow! Quick response. OK no IMS changeout. I had another conversation with my mechanic and he says in addition to the low probability, there are a few diagnostics and early warning signs he can check for at this point which will give me a warm feeling. Thanks all.

Everyone else beat me to it, not worth doing the IMS on a pre-'00 986. The chances of the dual row IMS failing are the same as any other car. My take on engine failure, is that I would rather save the money and "if" my engine ever fails upgrade to a 3.2L. :cheers:

I'm actually with Fiddlebog on this. While the tranny is out, might as well do it. I have a Tiptronic, so unless I have to replace the tranny for some reason I'm not going to bother with the IMS. My cost-to-risk ratio is too low.

But Mikefocke has the best answer.

^^ What he says.^^

I am on engine #5. I have never replaced an IMSB and all of the previous 4 engines failed for other reasons than the IMSB (timing chain, lifter, crank bearing, and I haven't fully torn down #4 yet but its not IMSB).

If it made it this far, it will make it until something else in the engine breaks.

That's what I did ....put in a 183k 3.2 three years ago, still running strong ....

I did the clutch on the Blue Boxster that I sold to a friend this spring, While the transmission was off I pulled the flywheel, then the IMSB flange (AFTER having locked the timing) and verified the IMSB. It turned smoothly and there was no play. I then pulled the seal off the bearing so that it would get direct oil lubrication. There was no grease in the bearing when I removed the seal. Put it all back together and it has been running fine since.
My logic and pictures here in post #60
http://986forum.com/forums/boxster-general-discussions/74909-sick-ims-bearing-3.html

I've heard about pulling the seal off. I've also wondered about doing the European Parts Solutions procedure of punching a small hole on the other end of the IMS behind the oil pump so to send oil to the bearing. That is IF for some reason I need to remove my Tiptronic.

Just say no. The cars are too old to spend the big $$ for preventative maintenance.
Drive, enjoy, replace (car or motor).

Lucky you:)

I'm still waiting for 3.4 upgrade, driving hard my 2.5 with original IMSB daily, currently at 91K miles.

Everything I've read since I've owned my car says the dual-row is superior to the single.

Your source? Link?

Thank you.

He means any other non-M96 engine car. ie agrees with you.

Gotcha. Thanks! :cheers: