rpratt

My 2000 996 is in for service, and the oil drip under the engine did turn out to be the rear main seal. As long as I just have to replace the seal, and not the engine, I'm OK with that, since I've put 95,000 miles on, 65,000 problem free since Porsche replaced the first engine under warranty.

I'm still on my original clutch so I'm going to go ahead and replace that while they are doing the RMS, since there's no extra labor charge and after 95,000 miles the clutch is probably decently worn.

Anything else I should have done while that part of it is dismantled anyway? IMS? any other suggestions?

Bob

PS: and now I really don't want to replace the car since they discontinued my color, meaning a new 997 would cost an extra $5,000 for a custom metallic paint. Arrghhh.

Macster

Be sure tech cleans and properly lubes all clutch hardware pivot points.

When my 02 Boxster in at around 20K miles to have RMS done I asked tech to do this and it made a noticable difference in the feel and action of the clutch which makes using the clutch an easier thing. Still on original clutch and car now has over 226K miles.

Tech shouldn't over do the lube thing and of course he should use a high temperature very thick grease.

At same time RMS done the service department upgraded the IMS seal. The old IMS end plate had a single o-ring seal. The new improved one came with a 3-ribbed seal and micro-encapsulated bolts. This micro-encapsulation seals the threads which if unsealed can pass oil since the IMS bolts thread into holes that extend into the engne crankcase.

Now your replacement engine might have the new/improved IMS 3-ribbed seal and bolts present.

Trouble is given the location of the RMS and IMS it is hard to tell if the leak is confined to the RMS or if the IMS is also leaking, or even if the IMS is leaking.

I had read this online somewhere and mentioned it to the service department manager and he said when a car brought in for a suspected RMS leak SOP was to also replace the IMS end plate with a new one with a new seal and 3 new micro-encapsulated bolts, just in case the IMS was also leaking.

Sincerely,

Macster.

jumper5836

I am thinking of doing my RMS and clutch next year. Would doing o rings and cam covers be less work while they are doing the other things?

Macster

There are two camps:

1) Let sleeping dogs lie/if it ain't broke don't fix it

and

2) While you're there

Personally if the o-rings (do not know what o-rings specifically you are talking about) and cam covers are leak free I'd leave them alone.

You won't know the new ones are leak free until you get the engine back in and running and then if they are not you're faced with living with the leaks or pulling the engine again.

'course, if you are an o-ring and cam cover seal god (not being mean, I've run into some mechanics who can seal something and it stays sealed!) then go after them both.

But, if you're like me... well, I'm not a seal god. I'm ok but I like to let sleeping dogs lie.

However, I will violate this let sleeping dogs lie thinking if there are wear items involved and I feel these are due to be renewed or worth peeking at in spite of oil or water tight seals/gaskets.

Sincerely,

Macster.

jumper5836

My car bellows blue smoke at start up when the engine is cold. Now it goes through a lot of oil and I don't ever see where it goes.

I was just thinking while there at it what else could be done at the same time that would save me some dollars down the road. I don't mind replacing stuff even if its okay right now.

rpratt

I checked today, and they did put in a new IMS at the same time. They said it was basically automatic when doing an RMS.

Interestingly, they said that while the clutch was decently worn, it was in amazingly good shape for having 95,000 miles on it. I'm still replacing it, but it was nice to hear that I hadn't trashed it quickly.

Bob

Macster

Emitting lots of blue smoke upon every startup and assuming engine not horribly overfilled with oil is different. Coupled with high oil consumption teh engine probably needs some attention.

However, does the smoking stop shortly after cold start? Does it appear at hot starts? Does any smoke appear if you run engine up to a high (nothing gruesome) rpm then coast on closed throttle then step on the gas?

While smoking unsightly and high oil consumption a bother as long as the engine runs ok and otherwise behaves...

Before you can know what to do you have to know or have a pretty good idea of what's wrong. Of course, overfilled with oil, or some problem with the AOS.

In short you want to eliminate any external easy to get at (at least without having to drop the engine) item that might be teh cause of this smoking.

Along with this effort a compression test I think called for. If you find some cylinders low on compression a leak down test with some extra effort might help you determine where the problem lies. If you for instance hear air hissing its escape from either the intake or exhaust side then valve seating issues are possible. Then the engine comes out or if the heads can be removed from the engine with engine in the car they are removed and a "top end" rebuild is done.

New or reground valves, refinished valve seats, new seals, and any other valve hardware replaced that shows signs of needing it.

If valves appear tight but some oil squirted in the cylinders reduces the amount of leak down then the suspicion turns to the pistons/cylinders and rings.

For this the engine has to come out and a bottom end rebuild done. New pistons (probably), new rings. If necessary the cylinders machined oversized -- just a few thousands of inch maybe and oversize by the same amount pistons ordered along with properly sized rings.

"while you are there" you look at the maiin and rod bearings and thrust bearing pads and freshen them up if they are in need of it. Clearances are of course measured and even the bearings look ok but are worn new bearings installed.

Of course, the crank may have an undersized main or rod bearing journal. It may be possible -- it is with some engines -- to grind just the worn crank main or rod bearing slightly undersize and source slightly oversized bearings. The crank may have to be treated to ensure the grinding didn't remove too much of the hardened material. I've also seen cranks ground a few thousandths of an inch undersized, then hard chromed and then ground to size. Ground a few of these myself years ago.

At the same time chain guides, tensioners, and the infamous IMS bearing examined and the items replaced that inspection determine need replacing. This might be a good time if you are so inclined to fit an aftermarket IMS bearing upgrade.

Or you just go though the engine top to bottom front to back.

Depends upon what you find, what your budget is, etc.

Sincerely,

Macster.

jumper5836

It has only smoke while engine still hot after DE sessions. Its a daily driver and never smoke up every morning until now.

It doesn't smoke when what you've described. Though I have seen black smoke on occasion doing that.

Both oil measurements always are in between the min/max indicators. It's never been over filled.

Thanks for the info. I think I'll have them do a compression test when it goes in.

mikes_996

rpratt, where in the bay area did you have the rms replaced? was it at the dealers or an indie? cost for such... i'm thinking of updating the ims...

rpratt

At a dealer (Stevens Creek Porsche). Basically because I'm lazy and they are very convenient to my office. Finding a good independent for Porsches is on my "to do" list, unfortunately neither of the mechanics I use for my other cars (one BMW specialist, one Honda/Acura guy) work on Porsches, and the dealer is the easy approach.

I haven't picked it up yet, but I think the RMS/IMS, with labor, and the clutch (parts only) ended up totaling around $2,500. I'm not sure because I'm also getting the 90K major service done at the same time, and I haven't looked at the breakdown yet to see which $$$ were from which part of the work.

bob