Silk

I will bring in the car for some maintenance next week. The tiptronic transmission will come out and sent for complete check and revision, with some small modifications

also on the list are
- Plugs and coils
- Injectors need to be checked.
- SAI codes P0491 P0492, SAI system check
- Most probably the alternator needs to be changed or revised.
- maybe replace IMS bearing with a standard SKF, last time changed was 20k miles ago*

Depending on the follow up of things it could be I will let them pull the engine, also it makes it more easy to take off the transmission and to work on the engine. Luckily hour rates are not that expensive over here compared to US.

So if the engine comes out which are the things I should further do/replace?
The car is a 2002 C2 with 106k miles on the odometer.

I bought already the following mods to be installed.
- stronger hex oil drive shaft
- updated spring and plunger for the oil pump

Should I have the flywheel checked and replaced?

DBJoe996

AOS, water pump and thermostat, vacuum canister (the one that sits on top of the engine), SAI check valves and all vacuum tubing, oil filler tube. Also might consider doing the O-rings under the oil cooler.

Silk

AOS, Water pump and (low temp) thermostat were replaced 25k miles ago. Will that be necessary again?

Schnell Gelb

First, well done for obviously reading other relevant Posts on the subject.
I suggest you consider replacing the 2 knock sensors. They ar difficult to reach in the car, are not expensive and cause very odd problems when they fail.
The other issue is parts that rust (I note you are in Holland). One of the most tedious jobs is removing and replacing broken/rusted exhaust header bolts with the engine in situ. Consider buying a stainless steel stud kit. They are cheap(EBay) ,easy to fit when you have space and access.
The injectors are inexpensive to maintain with new filter baskets and seals. Just make sure your car has the later '4 hole' injectors before you spend any money on them.
Check the infamous "Y connector' to the starter for corrosion.
Replace the equally infamous oil filler tube- it gets brittle with heat cycling.So does the AOS corrugated tube.
Lubricate and check boots on the C.V. joints.
Flywheel - you have aTip - so a flex plate. No DMF worries !
I am not saying all this needs to be done - just consider it & plan to keep the car for a very long time to get your money's worth !
Good luck and let us know what you do?

Silk

Thanks for the input. Oil filler and knock sensors will be for sure on the list.

Last year sports headers and x-pipe with 200cell cats were installed 0(from topgearshop in the UK). Luckily no difficulties with too rusty bolts. Only one of the oxygen sensors could not be removed from the old cats. So I replaced all 4 oxygen sensors. Indeed, living close by the sea is not an optimal environment

By the way, could de P0491 and P0492 codes be related to the aftermarket x-pipe?

The IMS bearing will be a regular maintenance part for me. With regular oil changes, spin on oil filter, magnetic drain plug and using Millers 10w50 nanodrive oil I will replace it with a standard bearing every 25-30k miles.