What constitutes good 996 maintenance practices?

[dgcook]

I now have a red 1999 911 coupe. It's just beautiful and I'd like to keep it that way.

It has 67,000 miles. Apart from the standard scheduled maintenance (e.g. appears it's about time to change the plugs)I don't see much listed regarding things like the clutch and other somewhat more major items.

This comes up because in reading everything I can about the 996 engine I find that much has been said about the weakness of the IMS bearing and RMS in 996 engines. Advice and opinion on this issue appear to be all over the map. I even called LN Engineering about it and received what sounded like reasonable advice---unless there are signs of a disintegrating IMS bearing (small metal shards in oil filter)or peculiar engine sounds the IMS bearing should be replaced as an item of standard preventative maintenance when you open up the engine to address the clutch.

Thus, my questions for the forum:

1. What do you think of this advice from LNE?

2. Is IMS failure inevitable and thus must be addressed?

3. If so how to estimate when? It sounds like guessing wrong is a huge mistake.

4. When is a good time to look after the clutch? Right now mine feels great.

5. Is there anything else I should be looking after at this time in terms of maintenance?

Many thanks to everyone.

Dave Cook

[rattles]

Hi Dave,

I faced a similar decision with my 99 996 IMS bearing replacement, I did quite a lot of research and spoke to my indy about it, he suggested waiting until I needed a new clutch but I am pretty easy on cars and didn't want to wait until then. We used the LN kit and while he was in there checked out the RMS which was showing no signs of leaking. The clutch was only 25% worn so we left that as it was.

While the IMS bearing didn't appear to be too worn the motor is noticeably quieter since the replacement.

As for maintenance I would suggest regular oil changes as a must do, I do my own changes between the normal services. LN also have a replacement oil filter kit which I am planning to get soon, the factory plastic canister with paper filter is replaced with a screw on oil filter.

A friend of mine had the IMS failure with his 996 and it cost him A$30000 for the replacement motor supplied by the local dealer, the cost of the IMS kit looks like good value insurance to me.

Glenn

Edited August 20, 2010 by rattles

[dgcook]

Glen:

thanks for the information. I also don't drive hard. What was your mileage when you did the IMS/clutch inspection? Having now been through this drill, do you think you could DIY?

best

dgc

Hi Dave,

I faced a similar decision with my 99 996 IMS bearing replacement, I did quite a lot of research and spoke to my indy about it, he suggested waiting until I needed a new clutch but I am pretty easy on cars and didn't want to wait until then. We used the LN kit and while he was in there checked out the RMS which was showing no signs of leaking. The clutch was only 25% worn so we left that as it was.

While the IMS bearing didn't appear to be too worn the motor is noticeably quiter since the replacement.

As for maintenance I would suggest regular oil changes as a must do, I do my own changes between the normal services. LN also have a replacement oil filter kit which I am planning to get soon, the factory plastic canister with paper filter is replaced with a screw on oil filter.

A friend of mine had the IMS failure with his 996 and it cost him A$30000 for the replacement motor supplied by the local dealer, the cost of the IMS kit looks like good value insurance to me.

Glenn

[rattles]

40,000 miles,

I wouldn't attempt it as a DIY, I dont have the equipment to get the car high enough and feel comfortable about taking the transmission out while I was under the car. Also from what I have read extracting the old bearing can sometimes be difficult, I prefer to leave that type of work to the experts. I do do most of the minor maintenance myself. Brake pads, brake fluid flush, oil and filters etc.

[rattles]

One other maintenance item that is worth doing and is an easy DIY is to remove the front bumper and clean out the radiators. If you live in an area with heavy leaf drop in autumn you will find they are packed with leaves, insects and sludge. Not sure if its shown in the DIY section here, from memory Loren sent details to me but I think they are only available to contributing members. I have some photos and can send them as a PM if you want them.

[dgcook]

Glenn:

Thanks for your offer. I would be happy to see any additional information you wish to send.

Regarding the IMS issue, your comments were the last push I needed to wade in. The indy shop I called already has the LNE parts on the shelf, so I have an appointment this Monday to do the IMS, RMS, clutch, and other standard items (plugs, serpintine belt, etc). They will also put in the LNE oil change kit I already ordered (magnetic drain plug and spin-on oil filter housing that changes how the oil gets filtered).

Since you've already done your IMS, perhaps you will be interested in something the mechanic said. I've wondered why some people think there is an inverse correlation between how hard one drives and the likelihood the IMS will fail (i.e. 996s driven by Hell-bent track monsters appear to be less affected than those who are more gentle drivers, like myself). He asserts this has been their experience and suggests this may be so because it has been shown that higher oil pressure from high revs promotes better penetration/lubrication properties of the bearings. Plausible for an enclosed bearing, I guess, but from my point of view this proves only there is yet another argument favoring replacement sooner rather than later.

Dave

[rattles]

PM sent, should have 10 photos attached if I did it right

[996driver]

Last months Excellence magazine had an very good article on the IMS and upgrading to the most current specs. Part numbers and tools were detailed. I still would not save the labor on this one.

Scott

[dgcook]

Scott:

thanks. I think I know what you are referring to--a two part series. You're right it was quite good and was the place I first learned about the IMS issue.

I also agree with your advice about labor. Next week I'm getting it done by an indy shop that does them routinely.

Dave

Last months Excellence magazine had an very good article on the IMS and upgrading to the most current specs. Part numbers and tools were detailed. I still would not save the labor on this one.

Scott

[tanny02996]

Well, the IMS issue seems to be more emotional than factual. No one seems to have a definitive answer on this, but it seems to me that very frequent oil changes are the best way to mitigate the risk of an IMS failure (I do mine at the earlier of 6 mos or 5k miles). You should just do what makes you most comfortable concerning the LN upgrade. Based on my recent experience...I'd recommend cleaning your drains...

Edited August 23, 2010 by tanny02996

[dgcook]

Perhaps to your point:

I had the IMS done today and went to see their work. The original IMS bearing was in quite good shape after 67K miles (I saw a one today that crashed at around 35K). RMS was leaking somewhat. However, the clutch and flywheel were clearly on their way out. Thus, in spite of all the IMS doomsday talk, it was a more mundane clutch/flywheel issue that required attention. One balance I think it was still a good decision to do all the work now. Including the new IMS and RMS was good preventative medicine under these circumstances and didn't add much to the expense of what turned out to be a job that was eminent anyway. I'm still going to stick to your advice of 6mon/5K miles between oil changes.

thanks for you input.

Dave

[tanny02996]

Since you were in there anyway, it was probably a small investment for a a lot of peace of mind...don't hear many (if any) people saying they regret doing the upgrade. I think the variable in the cost is whether or not you need to reset the cam timing...that can add a non-trivial amount to the labor cost. Sounds like you didn't have to do that though. Happy motoring!