DIY Time Alternator, Starter, Oil Filler Pipe, Wire Harness

Oil filler pipe on my 2002 996 C2 Tip 122,191 miles broke so I guess it's time to get dirty, scrapped up, and pissed off again. I know my original alternator is weak so I'm going to replace that and while I'm in there might as well do the starter and the wire harness between them. And of course the plastic connection piece between the oil separator tubes that's bound to break, because if I'm working on something it's bound to break. Anything else while I'm in there? The quote from a local Porsche shop was $2,136. Which seemed high to me considering I did not want a new OEM alternator or OEM starter. Here's the vendor and list of parts and prices that are on they way, about $550 in parts. I'm slow so this is going to take a while (parts arrive next week) but I will report back how it went. RareElectrical: New starter 996-604-103-00 - $102.95 Rock Auto: BOSCH AL0700X Alternator / Generator $ 211.79 $ 77.00core 1 $ $288.79 Pelican Parts: Connection Piece for Oil Separator Hoses Part #: 996-106-226-52-M100 $6.50 Engine Oil Filler Cap Brand: Genuine Porsche , 2002 Porsche 911 Coupe Part #: 996-107-035-50-M100 $14.25 O-Ring Oil Filler Tube to Crankcase (42 X 4mm) Part #: 999-707-348-40-M17 $3.50 Oil Filler Pipe Brand: Genuine Porsche , 2002 Porsche 911 Coupe Part #: 997-107-131-00-M100 $60.75 Battery Cable - Positive - Connection Point to Starter/Alternator, Note: Brand: Genuine Porsche Note: - Part #: 996-607-019-01-M100 $66.25

Seems a bit low for the starter. Got a brand new Bosch starter off Amazon for $200 something or other. Since it is a job to get in there, get a brand new starter. My oil filer pipe came with a cap, so you might want to check that out.

I did go with a new but cheap starter, others have installed this one with success. If it goes bad I will get some more practice being a mechanic, I hear it's easier the second time around. 😀

1 Big suggestion... Drop the engine as far as possible. I suppose I'm a bit spoiled (since my engine was out), but I can't imagine doing much work in there without taking off the intake plenum - just doing this has to be a bear without a few extra inches of clearance... Just my $.02 Good luck

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I do plan on taking off the intake plenum. If there is a way to drop the engine a few inches without disconnecting too much stuff I would do it. Any links to that procedure would be appreciated.

To gain a few inches you can remove the nuts on the motor mounts and use a floor jack to slowly lower the motor. Make sure to not stretch any coolant hoses. Good luck!

I have removed the air box and the alternator. Surprisingly, the alternator came out with no problem (relatively speaking) what so ever. Sure some shifting back and forth, wiggling, etc. but not the nightmare stuck alternator situation I have read about. I am going to do a write up on these two steps with pictures. I will also show pics of the electrical connections and how to disconnect them, where to push on them. I have struggled in the past with simply disconnecting wires and it sure helps to have a picture of the underside of the connector you can't see, which always seems to be where Porsche requires you to push or manipulate to remove. Sneaky Pete, thanks for the tip on lowering the engine a few inches. I will do this. I know how just a couple of inches of room can make a difference!

Keeping an eye on your progress as I am basically in there now...pointers are always helpful! Chris

Pelican Parts: Connection Piece for Oil Separator Hoses Part #: 996-106-226-52-M100 $6.50 Looks like you already ordered this. I would use this new connector, but cut off the plastic tips and drill it out to accept a brass connector which will never fail again.

I just finished installing a new starter & alt/starter cable (& new water pump/thermostat) but, I broke the oil filler tube installing a new serp belt which is a bummer. Now, I got to order a new oil filler tube and remove the alternator. I'm glad to hear you didn't have any difficulty removing your alternator. I'm hoping for the same luck. Well, I'm off to order the new oil filler tube... Mike

Remove the Air Box. - loosen up that silver hose clamp - green arrow - carefully move that oil filler tube out of the holder - blue arrow - remove bolt - red arrow - disconnect mass air flow sensor (see pic of underside) - pull out things holding mass air flow sensor cable in place (up to two of these) - purple arrow - some cars have an extra tube (see pic, yellow circle) that needs to be removed - now you should be able to take out the entire air box

The trick for alternator reinstallation that I found was rotating it about 1/8th a rotation counter-clockwise, then rotating the assembly about the same amount towards the back of the car. Slip the connections just under the plenum & the pesky lower left bolt can be gradually lined up as the upper rail & bolt is secured. nice DIY, thanks for sharing.

Not sure how old your AOS is, but it is not that much more work to get to it while you have all of that stuff out, may be worth it. I just removed mine this weekend, took 2.5 hours, hoping the install goes as smoothly. I'm in Philly too, so if you run into any issues, feel free to hit me up. I just did all of the things you are doing (my motor was out at the time), but I still may be able to lend a hand.

I will follow up with many more pics and steps for removing the alternator, intake, plenum, starter, oil filler tube, and wire harness between alternator and starter. Going to take some time.

Disconnect Changeover Valve to make more room before removing alternator. I don't think this is absolutely necessary but I appreciated the extra room.

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Not sure why lowering the engine would help? I've replaced all of these components without the need for lowering the motor. Only time I did that was to replace the AOS. Other than that the starter, alternator, and harness are easily changed without doing anything more than removing the airbox.

Remove the Alternator. Many users have reported problems with this step. The long bolt gets stuck, the alternator is stuck in place, hard to move out, etc. My alternator came out really easily. I did not experience any problems at all so I can't help much if your alt is stuck. - Loosen up but don't remove left bolt. - Loosen up right bolt (the one on the roller, this is the long one) - After you loosen up the right bolt, back it out three or four full turns - Now give the end of the bolt a whack with a drift punch or similar object and hammer - If it worked like it did for me, the alternator should be very loose on the right side and easy to move up and down. - Remove the bolts - Remove the alternator part way. Get the left side up and over that bracket, then get the rest out. - Disconnect the two electrical connections on the back of the alternator and then remove all the way out.

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You are correct. I did not end up lowering the engine as it was not necessary at all working on any of these items. The Air Oil Separator (AOS) would of course be a different story and there is no way that's coming out without lowering the engine, at least from what I can see on my 2002.

Thanks for posting the alternator removal procedure. I'll be tackling this over the weekend. Mike

You may want to consider using a 997 alternator. Here is a good thread on this: https://rennlist.com/forums/996-foru...nto-996-a.html

I have made a lot of progress and will be updating with pictures and tips as soon as I can (may be another week). So far removed: airbox, alternator, throttle body, plenum (t shaped air distributor), wire harness between starter & alt., oil filler tube. Reinstalled: new starter, new wire harness between starter & alternator, oil filler tube, plenum. I used tips found in other write ups, some of which were very helpful and I will include those in my write up. Wire harness between starter & alternator - removing the plastic box at the end of this harness, using the hot water technique to loosen it up, WAS ABSOLUTE GENIUS! Props to the Rennlister who posted this DIY tip !!! (i will give credit in my write up later). It worked perfectly and eliminated A LOT of unnecessary extra work.

I used the 150A Bosch AL0815N alternator intended for a 997 in my '02 C2 996. No trouble with fitment, and I was able to buy it from Amazon w/o a core charge. The old 996 alternator went to the electrical rebuild shop and is on-hand as a spare.

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Congrats!!! I finished my project yesterday...water pump, thermostat, lower idler pulley, upper idler pulley, oil filler tube, stater, starter/alternator cable, and serp belt. Car is running great! Mike

Throttle Body removal. This one is pretty easy! - remove 4 bolts - disconnect the electrical wire - done!

T-style Air Distributor Removal (Plenum) Some have reported problems removing and installing this part and I can see why. Some force is needed when you pull the part out and again when you try and push it back in place but there are a couple of tips that might make the job easier. - See the green box with the green arrow? That connection to the air distributor needs to come off. Reference the second picture for a close up of what it looks like disconnected. Pretty straight forward. - Now loosen up #2 and #3 ONLY (the inside hose clamps) try and move the Plenum up and down. The goal here is to break the seal (if there is one) between the plastic T-style air distributor and those rubber boots. - Now loosen up #1 and #4 (the outside hose clamps) try and move the Plenum up and down (same as above) Some people tighten down #2 and #3 while working on breaking the seal of #1 and #4. - I encountered no problem with the T-style air distributor sticking to the rubber boots. - At this point you should be able to easily move the air distributor piece up and down in place. Mine moved very easily right away once the 4 hose clamps were loose and the connection (top left) was detached. - Rubber Boot Hose Clamp #3 (Right Side) - loosen this one up enough so you can slide it to the LEFT onto the plastic air distributor and OFF the rubber boot. The goal is to remove the rigidity of the metal clamp out of the way so there is more "give" on the right side rubber boot when you pull the T-style air distributor out. - Rubber Boot Clamps #1 & #2 loosen those up (do not remove) and shift / push the rubber boot itself as far to the LEFT as possible - Now the moment of truth, YANK OUT THAT AIR DISTRIBUTOR! .... carefully of course...it WILL come out but you may need to use a little force. Try pulling out the right side first and once that gets past the rubber boot on the right, the rest should come out easy. - CAREFUL!! not to break off that black bracket (lower left corner) just in front of the air distributor. Ask me how I know! - Replace the rubber gasket between this piece and the metal throttle body.

And the starter is revealed! Along with the wire harness between the alternator / starter / and positive battery terminal. Turns out the dirty dirty starter you see is actually not very old. It's the real deal Bosch made in Germany in 2014 and stamped with the Porsche part number... and it's EXACTLY like the one I purchased off Amazon for $102, exactly the same. So the starter did not need to be replaced, but I went this far so I replaced it anyway. And, as a result, I can tell you exactly how long your extension needs to be to remove the two 15mm bolts holding the starter in place. (19") pic to follow. Where did all that oil residue come from?? Could it be from my cracked oil filler tube? (the reason I started all this) I hope so. The Plenum removed earlier was SPOTLESS inside. But as you can see the outside of the rear air distributor (above the starter) is also pretty dirty with dirt and oil residue all over the outside. Anyway on to the starter removal....

Starter removal. - Pull up the rubber boot (green box) note: older wire harnesses may not have this updated rubber boot. Remove the nut under the rubber boot and disconnect the wire harness from the starter. - Remove the smaller nut to the right (green box) and disconnect that wire. - Now you are only two 15 mm bolts away from pulling out that starter. - Tip, if you have a small can of WD40 or 'PB bolt blaster' with a straw extension nozzle now might be a good time to spray those 15 mm bolts.

Here's the socket wrench and extension set up you will need (or something similar) to remove those two 15 mm bolts. The upper bolt (which you can see in the post above, blue box) is fairly easy to get to. The lower bolt is a little more challenging.

Starter removed. New starter installed. up next... replacing that wire harness...

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The fun part is getting the lower nut in place & not fumbling with it above the case. ty for that.

By the way, if I can do this, anyone can do this. I do have a lot of tools but otherwise no special talent. Take your time. Take pictures before and after with your phone. Having pics for reference can really help later on. Removing all the parts made everything a lot easier to access and was worth the extra effort. I did this in my fancy garage you see below...

I just realized the lighting in my garage wasn't too good. Here, I turned on the lights for a better pic.

Beautiful collection

Replacing the Wire Harness. The main point here is to remove the plastic box on the wire harness that connects to the 12 volt power supply. The reason you are removing this box from both the old and new harness is simple.. to make it easier to remove and then install the wire harness at the 12 volt location without having to remove the A/C compressor or the power steering fluid box etc. The plastic box goes back on in the end.

Absolutely awesome write up! You made this way easier for me when I eventually have to do this stuff! THANKS Chris

Oil Filer Pipe - with all the previous parts removed the oil filler pipe is easy to access, it is held in place with two bolts - when installing the new part be sure to use a new O ring

When it all goes back together and starts on the first try! One result of replacing the alternator and wire harness is a dramatic improvement in how quickly the car starts. There is no starting hesitation (hot or cold), it just fires right up!

Hi, great info here. Thanks. I'm having common issue of sluggish starts when hot. New Battery and with car at 2000 rpm, only showing 13.2 volts at battery. Lights dim with car on. ....I think it's alternator. Local INDY does too after his testing.... even though I changed alternator with Bosch rebuilt 4 years ago. Starter is 2 years old and Bosch....Other common cause is the "Y" cable from alternator to starter. Rather than going through process of changing that, I checked resistance between cable at alternator and positive post in engine...got 3.4 Ohms which is what I get checking any 1 foot wire I have hanging around. You guys think that confirms "Y" cable is OK? I was just going to start with new Genuine Porsche alternator..$1300.... Advice? Thanks, KK

KK, Before you start throwing an expensive alternator on, check some of the posts Ahsai and others have done about chasing these voltage gremlins down. Also, a voltage regulator is cheap...alternator, not so much. You may want to try that before an alternator swap. There’s also a post on this forum that instructs how to install improved grounding for the start system. It was something I did when I replaced my voltage regulator a few months ago and it was wicked easy.