I'll be pulling my 140,000 engine and transmission, what should I replace or inspect?

[Jeffd]

2000 S, 140,000 miles. The car just recently became a pleasure to drive because I completed a full suspension and brake refurbish on it. But, with the more frequent driving some drivetrain issues that were present when I bought it have advanced. I've got a handful of issues that need addressing and I think I've resigned to just dropping the engine and transmission to do it all in one weekend. I have access to a full mechanic shop with lift, engine/transmission jack table, and air tools as long as I can finish the job between a Friday at 3:00 PM and Monday at 7:00 AM. I've successfully done an LS motor replacement in a GM truck in a weekend, as well as all manner of typical maintenance jobs like Asian timing belts, water pumps, tensioners, etc. so I'm not concerned about being able to complete the work. Depending on how long it takes me to get the tools and parts together I may do it over Labor Day weekend and that'll give me a bonus day.

All of the following parts are less than 2 years/10,000 miles old and I don't plan to replace them again:
-AOS
-Spark plugs, tubes and o-rings
-Regen valve
-Water pump
-Upper power steering reservoir
-Ac compressor


I've contacted Pelican Parts to see if they can setup a cart for me with all of the parts but here's what's on the agenda. If anyone happens to have parts lists for these jobs that would be welcomed. I have the 101 projects book that I still need to read these sections of.

-Timing guides and tensioners- I've got all the rattle/gurgle noises and lopey idle associated with this problem and they've gotten worse recently. I know I should do o-rings, valve cover gaskets, the timing inspection covers, here. Should I consider replacing the oil pumps in the heads?

-Replace clutch- something OE comparable or a mild upgrade if it made sense to do so. It makes rattles right now when the pedal is depressed. I suspect I need a throw-out bearing here too. I know I'll need a new set of flywheel bolts. What else should be done here? Are the pressure plates typically useable at this age or do they need replacement?

-Replace IMS and RMS- I have engine oil leaking slowly from the bellhousing so it's likely the rear main seal or the IMS seal so I would like to replace both. I don't anticipate getting another 100,000 out of this engine without it having to come out again anyway so I think I'll just do the Pelican IMS bearing unless that seems like a terrible idea. Who rents tools besides LN Engineering when you buy their IMS bearing? I see that Ben Auto Design/uniWerks has one for $50 rental but they're out of stock. Edit: It was the supplemental tool kit that was out of stock. I was actualy able to rent the LN Engineering kit from UniWerks for $50 + shipping + $300 deposit.

-SAS delete- I plan to block off my secondary air injection system and switch to a ROW tune later to eliminate the resulting check engine light... I already have a recurring CEL for SAS anyway so I know that system has problems and I don't want to repair that system. I hope to have a PiWiS setup soon where I can turn this off in the DME.

-Motor and transmission mounts. I plan to replace them all.

-Shifter cables or end link improvement kit- My car shifts like a dream in the warm but it's hard to find gears when it's below 50F until it gets good and warm. I replaced the fluid with Porsche OE fluid I ordered from Pelican but it's still the same and the level is the correct depth below the fill hole. I've already replaced all of the moving parts of my shift lever with the UniWekrks/BaD shifter, and side lever, which is really nice. That made the lever feel a whole lot better but did nothing for the cool weather shifting. I suspect I need at least an end link fix kit but should I consider replacing the cables while I've got a wide open engine bay?

-Should I replace that spring in the main oil lift pump while the engine is out? I've never seen the dreaded low idle oil pressure thing but should I do that preventatively?


Is there anything else I should consider? Some of my coolant hoses were replace with the water pump before I owned it but I'm not sure which ones might be risky. I'll probably replace all the little sections of hose I can get to. I don't have a leaky oil dipstick hose but maybe I should replace that too?

[JFP in PA]

I wouldn't go near the pelican IMS retrofit for your car. Yours is most likely a dual row engine, and the pelican answer for that is a single row bearing and a spacer; so, you would end up replacing the most durable factory IMS bearing with the most questionable factory IMS bearing.

[redpepperracing]

You didn't mention it, but the coolant reservoir tank would be a definite replacement item while you have the engine out, if you don't have evidence of it being replaced recently. There are no valve cover gaskets, it's just sealant, and for the camshaft removal there is a special tool set for that, so if you plan on doing the guides you will need that tool, or make one. Also I would change the two chains at the same time, again, while you are in there. You mentioned doing tensioners, that is a good idea, I have not seen anyone really recommend replacing the oil scavenging pumps in the heads, but new o-rings would be good. That goes for anything you take off, of course. A relatively cheap thing is the oil pump release valve and spring, use the upgraded 996 one, there are threads here on that. Could also do the oil pump drive key, again, there are threads on here about that. Also didn't mention the thermostat, although I would assume that was changed when the coolant pump was changed.

I can't think of anything else off the top of my head that you haven't already mentioned.

Good luck!

[Marc_986]

If it shifts fine when warm, I see no reason for changing cables and linkage. I don't have much experience with these gearboxes, but I guess it is just to be expected as I had similar observations on my older BMW. It did help to do annual gearbox oil changes, but never solved.

Looking at your list I think most if not all can be done with the engine in. If you can just pull the gearbox, it'll be far less work.