Dropping both Engine and Trans to do IMS?
 

My Boxster went in to have the IMS and AOS replaced today. Something I've wanted to do since I purchased it two months ago.

While giving me a tour of his shop and the projects he is working on, he mentioned to they will get started on my car today and drop the engine and trans. He prefers to drop the entire engine to do the IMS.??? He mentioned he's going to check all my gaskets, belts, etc. and will replace if he sees anything needing it.

It didnt' strike me as odd at the time, but I've been thinking about this all day.

Anyone else have their engine dropped when their IMS was being replaced???

Don't second guess an experienced mechanic. Instead ,I suggest you focus on a 'while you are in there' list to take advantage of having easy access to the engine. ASk here for suggestions to add to that list but a competent Indie will already know. This is a great opportunity to avoid some large labor expenses and some needlessly long diagnostics in future - for example , finding vacuum leaks !

Thanks for the wise words. Yes, we've had that discussion already. I recommended he take it for a pre-service test drive to see if he agrees with me the engine was purring and running smooth. I asked about the RMS, but he said if it's not leaking, not to change it. He mentioned they are very tricky to seat perfectly. We agreed he'd look at the spark plug oil tubes, serpentine belt, pulleys, etc. He is going to change the AOS. I don't have an unlimited budget, however! LOL

I would be concerned about this shop. You definitely do not have to drop the engine to do the IMS, and his explanation of why is questionable as these engines have few gaskets and the belts are easily accessible. More worrying is his comments about the RMS. We always replace the RMS when doing an IMS. The seal is less than $20, and Porsche released an updated version a few years ago that is way better than the original. While his comment about setting the installed depth of the RMS is correct, it also tells me that he does not have the correct tools to do the RMS, as a blindfolded chimpanzee can set it correctly every time in a couple of seconds with the right tools. The RMS seal is cheap, but it will cost you a couple of grand to get at in the future if it starts to leak, so it needs to be replaced with the updated part while you have the car apart for the IMS bearing.

" I asked about the RMS, but he said if it's not leaking, not to change it. He mentioned they are very tricky to seat perfectly. We agreed he'd look at the spark plug oil tubes, serpentine belt, pulleys, etc. He is going to change the AOS."
Those are all items that a diy mechanic can replace with the engine in the car.There are plenty of examples of exactly that here in Search. I too am doubting the title "Experienced Mechanic" - certainly not with a Boxster Ask here for a referral to better M96 mechanic in Tampa. Look for one Approved to do the LN Engineering IMSB for example.

I did my RMS and IMS and I decided to NOT perform the RMS replacement. I even had the seal. Having done many RMS seals before, there is no benefit in disturbing a seal that is working fine. There are cases where doing so actually creates a leak if the new seal isn't good and/or the surface is not 100% - obviously you can check all these things, but why break something that isn't broken.

In saying that, the effort to be wrong and pull the gearbag etc is my effort and zero cost (other than my time) so that's an easy decision to make. Just wanted to mention that I support the mechanics view that if it is working, leave it alone - seen times when someone who "changed the RMS" and when it wasn't leaking and now it is. Hard call to make and damned if you do and damned if you don't.

Finally got my Box back and wouldn't you know the RMS WAS leaking. So I had the RMS, AOS, and IMS replaced. He went over the engine, drivetrain, and suspension and everything looks great.

A couple of curious things I learned. LN supplies a sticker to put on the boot lid to certify the IMS Retrofit has been completed on the vehicle. They also ask for the old IMS and an oil sample to be sent back to them for inspection. Anyone else send theirs back?

For those looking at used vehicles which claim they have the IMS Retro, the sticker in the boot might help determine if it was genuinely done.

I have the LN IMS trunk sticker and the complete invoice breakdown as proof. They gave me my old bearing & flange and no oil analysis was done. The old bearing looks and feels fine and makes a great paper weight/conversation starter.

PS: Hey, look at that, my 500th post!

Congrats man!

P.S. My IMS had very slight play in it. So I feel better about replacing it.

We send everyone back, and the sticker is supposed to go in the driver's door jam.

The only time we have seen the newer PTFE RMS seal leak is when they were installed incorrectly, with the wrong installed depth, dirty seal area, or use of any kind of sealer being the most common issues. If the crank and seal bore were cleaned, and the seal installed dry and to the correct spec, they seem bullet proof.

+1 That's where mine is on both cars and both bearing were sent in.

I'm starting mine tomorrow and only plan to remove the trans.

Unfortunately not everyone in the world can get you to perform their RMS seal change - so they have to rely on themselves or someone else to do it right, and that's taking a chance that it won't be done correctly (as you've pointed out).

So when the RMS wasn't leaking, taking that chance for no extra gain seems a little bold and bordering on foolish.... YMMV

You make it sound overly complicated, and it definitely is not. Many people have even made their own tools to do this, and completed 100% successful installations. I've even seen it done correctly using a $4 CPVC pipe coupler and the old flywheel bolts. This is not rocket science.............

And your "gain" is a seal that will probably never leak.

My LN IMS sticker is in the driver's door jamb. Just FYI.

Chris

You know you're trying to sell it both ways right...

Be extra careful installing it to the correct depth and stay within 1 billionth of a mm of the crank's end bits; ensure it is microscopically clean with zero fingerprints on the seal or on any nearby parts with a 1 foot radius; and don't install it slightly off centre of which you need to use Porsche special tool ABC with toolkit XYZ which will keep you within 10 kms of the equator. Follow these tips or it will leak all the oil in the first crank etc.... and you ordered the right seal too yeah?

Oh, and the process is so easy a blind monkey could do it... in fact every grandma with a wrench does them before lawn bowls on Sundays using just used toilet parts that having been cobbled together using tape, glue, spare cut bolts and a toe nail clipper.

So yeah why wouldn't you do it !?

I'm happy having left the working RMS alone and will investigate it again if it ever decides to leak, and I'm fine with that decision :-)

G