Tune up time... what to do, what to leave

I have a new to me 1999 996, 97K miles, coupe, 6 sp. PPI performed, no serious issues, but obvious differed maintenance, appears 90K service was never done. I have changed motor mounts and trans fluid, poking around under there reveals 4 of the 6 ignition coils appear to be original (or at least old style) 2 are the new style. Planning to replace all 6 (and the plugs of course). Should I also replace the spark plug tubes? I've seen some people have pulled theirs and it appears that the o-ring was not seated right maybe from factory, heard they can break, etc... I don't want to swap out something that is working and risk more problems, but if these wear out and get worse with time, I'd rather swap them all now, it's only $30, seems like cheap insurance... Just curious if this is something that is only recommended if they are leaking/weeping oil or if 90K and 23yrs they are due. It appears i have a little weeping from one or both of the plugs that have the new ignition coils in... not enough to drip. I'm planning to clean up the engine to better track it down. Last item on my list. Planning to replace the belt and pulleys, I'm torn on the water pump, PPI didn't mention water pump, and it appears to be of a more recent vintage, it's quite clean. I've read horror-stories about these failing, do they normally give you some warning before they go? should this be top of my list to replace just for peace of mind? Thanks for the help, this is my first Porsche, most of my experience is air cooled VW, so I've got some catching up to do!

I'd replace the spark plug tubes and water pump preventatively. My water pump was original from 1999 when I replaced it last year (!!!) and had zero problems. It's cheap insurance because if it fails you're going to have a bad time.

Quotes source post: 17973807

I�d replace the water pump. Previous owner of my car must have let it fail before changing it and a couple years after owning it, it came to bite me in the ***. A lot of time and money to fix the intermix issue it caused.

Agree with others, while the coils are out, you should change the spark-plugs and spark-plug tubes. The o-rings are known to deform with age and will leak oil. While you are down there, you should also check the Solenoid-Cam-Cover seals, one on each bank. Mines were seeping oil so I replaced both (~ $10 a piece from Pelican). Regarding water-pump, I also changed mine preventively at ~43K miles and glad I did because couple of plastic fins showed severe wear, just with age, surprising... Cheers,

Quotes source post: 17973929

Thank you for the advice on the solenoid cam cover seals, I will add those to the shopping cart I have open on Pelican. This is exactly the kind of feedback I was hoping to get.

Quotes source post: 17974810

^^^ You�d be much better off shopping at FCP Euro. Believe it or not everything you buy is guaranteed for life (that�s right, when it fails or wears out, return it for replacement - even brake pads!)� Their prices also beat Pelican at least 90% of the time�

yeah i checked them out too, in this case Pelican was cheaper for the exact same parts.

For sure water pump, thermostat and any suspect hoses/clamps/hardware. I'd also remove the mufflers and do the Gundo hack while you're at it. Removing the mufflers makes replacing the plugs much, much easier IMO.

Quotes source post: 17975885

Well this just sent me down a delightful little rabbit hole, the Gundo hack sounds perfect, I've been thinking I'd like just a bit more music from the flat six, this sounds like just the solution.

Quotes source post: 17975842

That's surprising since the water pump is about $55 cheaper from FCP and lifetime warranted, coils were cheaper too.

I wanted to get the Beru coils and plugs, and I think it was cheaper on Pelican, and in terms of the water pump I was under the impression that Pierburg was OEM, so i wanted to pick up the Pierburg, It's a bit more expensive and I didn't see a Pierburg option at FCP, and while lifetime warranted is good, I don't really care about a $300 pump warranty if it fails and destroys my engine. Honestly, i don't plan to put a ton of miles on the car (before i got the 996 my daily driver saw about $5000 miles year, and the 996 only comes out when i don't' need two car seats and the weather is nice). So i don't plan to wear out anything i put on this car. I'm a total noob here, most of my preferences come from searching this forum so if I'm off base on my assumptions i haven't checked out my cart yet! I can still change!

FCP stocks the Pierburg water pump. https://www.fcpeuro.com/products/por...008314#fitment Even if they stop selling a product, they still honor the lifetime warrantee and will have parts drop shipped from the manufacturer.

+1 on FCP. A lot of people will tell you the waterpump should be replaced on a time interval regardless of mileage so keep that in mind. I think Jake recommends every four years which seems extremely excessive to me (considering my original pump lasted 20 years) but he knows these engines better than anybody. If you're already draining the coolant to do the pump adding a low temp thermostat might be a good idea as well. You can buy a special expensive one from some of the M96 specialists that is apparently the best option but I've never seen data that indicates how it differs from the cheaper name-brand thermostats that open at the same temperature. FWIW the FCP option for the thermostat includes the housing and will not require the special tool that some vendors sell.

FCP is a very good supplier, especially with their life time warranty. It even covers oil ! But for heavy parts beware that you need to send the used part back. Still FCP is great.