90k service is coming up, should I do it myself?

I took a quick look at my odometer this morning and it looks like I'm going to be due for the 90k service soon. I'm trying to determine whether this is something I should tackle on my own or not. Brake fluid flush and oil changes I've done so I can easily handle those. The belts have recently been changed since I had my alternator replaced a few months ago. So that leaves us with the spark plugs and possibly the coils. Is this the sort of job I can tackle with just jackstands and a little more than beginner experience? Or is this service something bigger that I should just have my Indy take care of? I've got some time in a couple of weeks where I can actually have the car off the road for a week if I need to.

Renntech has a detailed list of items covered... read THEN decide. if you do it, simply print out the list and record it. Keep it with your other paperwork... IMO, it can be done at home

90K service includes changing differential fluid. I had my transmission fluid changed also.

You only have to change the coils if there bad or going bad. If they have cracks, replace them, if not, reinstall. If you don't drop the exhaust the plugs will take some time but they can be done with the right amount of patience,swivel sockets, and extensions.

Dennis, he has a C2 tranny fluid is a snap and there is no diff to worry about TiP or 6 speed?

Oh... right... I forgot that there are a few RWD Porsches out there...

Six speed and yeah, only RWD. From what I've read it seems that dropping the exhaust makes life a bit easier as does having the right tools. I think I'm going to attempt this one. I've changed plugs before so aside from the crammed conditions hopefully this should be doable.

I think you can do it - and we are here to help (but work odd hours )

Do It

My thoughts from another post: I have a '99 C4, 89K miles. The service for 90K includes spark plugs, rear and front transaxle fluid, air filter and a bunch of inspections. I decided to do this myself. Here was my experience: Spark plugs- not that hard, space is very limited and I spent more time bending and contorting to get a good angle to twist and turn the bolts. Allow maybe 5-8 hours your first time as it is very tedious and many breaks are necessary. I found one cracked ignition coil and another ready to crack. Also there was some oil seeping out of 3 spark plug tubes. I ordered 6 new coils and the spark plug tube gaskets from Sunset- a few days delay for shipping. I used a boat transom plug to remove the spark plug tubes. Again space is very tight and it was tedious to keep trying and trying. On my car (3.4L engine) the spark plug tubes can be removed without removing the spark plugs. Now I am ready to put it all back together and I lift the car by the engine lift point. I get the dreaded puddle- the engine mount split. I am in the camp that says it was a matter of time as engine mounts are wear items. A call to Pelican Parts gets 2 new engine mounts on the way. A few more days delay. Engine mounts are an easy DIY. The draining of the rear transaxle is easy and straight forward. The front did not go well. I rounded off the fill plug. It took 2 weeks to get a new plug as the only source was Porsche in Germany. I ended up having an indy shop get the rounded plug out. I went with porsche fluid. Other hints: If you do this on jack stands like I did, wear safety glasses. Stuff will fall in your eyes. When you screw the spark plugs in, tape the socket to the extension. After all of that I have not noticed any huge difference in the car. Gear whine decreased some but everything else is about the same. Hope this helps as guys start to see 90K.

Do it, but drop the exhuast its only 5 bolts on each side makes the change sooo much easier.

Ok I decided to do it myself. Now I figured since this is going to take me a while, I might as well do some of the "while you were in there" tasks. So do you all recommend also replace all six coils and spark plug tubes/o-rings? None of them are having any problems now but I'm just thinking, if they lasted this long then this should be a repair that will eliminate any surprises in the future. Is that the general thought here?

Pix and a time line and good write up would be great!!!

Also, after the 90K service then what? It doesnt need anymore?

Quotes source post: 7437660

inspect coils for cracks, replaced cracked ones you dont have spart plug tubs like the 3.4 If you plan on doing some other items check the AOS for leaks (BTW there is a new one in the f/s section for $70 !!) I would pull the tensioners and check for wear, replace o-rings, clean the radiators, do a brake flush.... hmmm, thinking of more later

Quotes source posts: 7438198, 7438200, 7438366

Good idea! The only thing is that the whole reason I'm doing this now is that the wife and kid are heading to Grandma's house for the week. So I'm dropping them off (in Pennsylvania!) this weekend and I'll work on my car every night when home from work. So the timeline will be a bit weird since it won't be in one sitting but in any case I'll keep track anyway. There are regular maintenance intervals that I was reading about in the manual last night. So even after 90k there are still milestones. Ah! See you learn something new everyday. So I don't have to worry about spark plug tubes at all? Cool! I'm going to wait on the brake flush as I just did one about six months ago, same with the oil change as I'll do that right before the warmer weather hits us. But with these coils no one replaces them just for preventive measures?

Past threads indicate 2 options. 1-replace all coil packs if one or more are deemed bad/cracked.2- only replace the coil packs that are bad. Guess it's up to you.

I would not replace unless bad..... and if one goes bad, it will throw CEL, easy to know its bad then....replacing the "cracked ones" is preventative maintenance

A bit of advice for shade tree mechanics. Use the correct size sockets and wrenches of good quality that fit the nut and bolt flats well. Hold the tool at the proper angle so it contacts the fastener squarely. The same goes for torx and socket head fasteners. Hold the tool so that if the fastener suddenly breaks loose, your knuckles or fingers will not sustain injury. Safety glasses are your friend. Brutal force often destroys fasteners and fingers. If confused, ask somone more familiar with the job, guessing usually leads to disaster. Upon assembly, when tightening a fastener, tighter is usually not better. If uncertain as to how tight is good, get a torque wrench. Most things like to be tightened sequentially, aligning parts carefully before final torque is achieved. Check and recheck your work. After work is completed, start vehicle, look for leaks or unusual sounds. Wash up and smile.

Got under the car and removed the heat shields to take a look at the coils. They looked good! But one of them, the passenger side closer to the front of the car, had a bit of oil on it. I'll have to clean it up when I do the plugs and figure out where that oil is coming from. It's not much as I don't have any dripping on my garage floor but compared to the others (which looked very clean) this one had a bit of residue on it. So no coils this time.... But I can absolutely see how these plugs are going to be tough to get to. I didn't even lift the car to remove the shields and I had to snake my hands between the exhaust and the engine. So I think I'll have to remove the exhaust to get access without bending my forearm in two places.