johnarusso

I did a quick search in this forum on 'alternator' but it does not seem that alternator failure is that common, as I found nothing. I have 90K miles and mine just went out.

I was left stranded by an idiot light that was meaningless and undocumented in my owners manual It's a picture of a little red battery and a warning that was effectively meaningless.

I was 250 miles from home in the California Sierra with effectively no cell coverage. I managed to get towed to a local dealer who wanted close to $2500 for the repair, but didn't have the part and it was a Saturday. A long day - left home at 5:00 AM and limped back in around midnight.

The following week I trailered the CTT home and began the project.

Everything has to come out to get to the alternator. Front spoiler/cowling. Turbo charge air cooler. Drain the collant. Remove the Y-pipe. Move the hood latch to the service position. Remove the serpentine belt. Remove all the Turbo piping on the right side to get access to the generator.

Drain the coolant (this alternator is water cooled - who knew - made by Delco and no rebuild parts are available for it).

Now for the hard part - (only joking a little). Wrestling the alternator out of that tight space is a challenge. And the book shows 3 bolts but I had four - no swearing was involved in figuring that out!

If anyone has had a similar experience or has a failed alternator I'd love to know your experience. I am halfway in an I will be buying a rebuilt unit from the dealer tomorrow and hopefully be finishing the job by the weekend.

And while the entire front end of the vehicle is dismantled, I will chase down the source of all the oil and grime that I have to clean of the engine.

Chris51080

You'll want to check into the coolant pipe replacement threads. Typically, when they go, they will take the alternator out with it.

The water cooled alternator is pretty cool. My first experience with one was on a 1999 BMW 540. Never knew they existed until then.

johnarusso

Thanks Chris. Pipes were done ages ago - under warranty. After seeing how tightly package the engine is with cowlings all around, the water cooled alternator makes sense to me.

Just picked up the parts from my dealer, Sonnen Porsche in Marin. They've been great to me and have a great online store for original parts at discount prices. Tell Henry I sent you.

FYI for anybody doing this job.

The original unit has the wire going into it sealed. You have to cut the rubber housing off in order to remove the plug.

The gotcha is installing the new unit. It comes with a pigtail about six inches long with a male connector in a waterproof housing. You have to cut and crimp/splice in the mate to it. If you do not have the proper crimp tool for this connector, which unless you are an electrical engineer like me, I doubt you do, my advice is to crush/crimp it on with whatever tool you have and then solder it.

The dealer says they get their tool from Snap-On, so I doubt even they are using the proper tool with the proper die for this particular connector. I have a tool made by Molex that I've had for years and it's several hundred dollars. The dies are extra and since I have no idea who makes this crimp on nor what particular part number it is, I doubt I can be sure of finding the proper die for it. I may resort to the soldering to ensure a reliable connection.

I'll post pictures later.

johnarusso

More than anyone wants to know about proper crimping. Smashing it with whatever tool you have at hand may seem to suffice. But if you are interested in what proper crimping means here is a link with some good info. Note the rule that says to use the manufacturers recommended crimp tooling for the specified connector.

http://www.molex.com/tnotes/crimp.html

johnarusso

Hey Chris. Just re-read your post. I had a 1999 BMW 540 also - 6 speed manual with the big V8. Loved it. Sold it to buy the Cayenne. Did you have the 6 speed? I never got into working on that car. Didn't have it long enough and lived in SF at the time so no room to work on it either. Had no idea about water cooled alternators until I started digging into the Cayenne this week.

Slow Guy

I've been reading these threads for a while and this is the first I've heard of the coolant pipes taking out the alternator. Starter yes, alternator not so sure about.

I changed my pipes out proactively and changed the water pump and serp. belt at the same time, left the thermostat alone though.

JohnnyBahamas

Oh, now THIS is bad news.

Because as far as I remember ALL alternators eventually go bad.

Alternators go bad. It's just a fact of life like death... and 955 Cayenne coolant pipe failure.

So, this write up on the incredibly difficult process to replace the alternator is disturbing.

Insane complication to replace a guarantee fail part.

OK, note to self... when the red battery malfunction light comes on, sell it.


After reading this thread I upgraded my AAA Emergency Road Service membership to Premier level which includes 200 miles of towing... hopefully 200 miles of towing PER event.

Water cooled alternator embedded like a tick... great.

Chris51080

You are correct, it was late last night and I got my electrical components. Mixed up.

It is the starter that goes with the water pipes, not the alternator.

As for my 540, yes it had the 6 speed stick. It really was a great car.

philg3

Funny you say that -- I did the exact same thing (upgrade to Premier Level) for the last two years I owned a 2004CT -- waiting for the glycol smell. Eventually, I was so freaked out by the thought of getting stuck in the mountains, I spent the $2K+ to replace the pipes -- prior to failure. Turns out, I never used the Premier level, and dropped AAA entirely when I got the 2013CD -- now relying upon Porsche Roadside Assistance during the warranty period.

Slow Guy

Strangely enough AMA (American Motorcycle Assn.) roadside assistance plan covers both motorcycles, cars and the trailers being pulled by both cars and motorcycles and their service covers more mileage than the AAA Basic coverage. In addition it's cheaper than AAA Basic. When I found out I signed up for AMA Roadside and dropped my AAA.

whistle34

"OK, note to self... when the red battery malfunction light comes on, sell it."

SORRY but its too late then! mine went about 77k miles and $1900, only Germans would mix water with electric

johnarusso

Having done the repair myself, I know why it is water cooled (and oh BTW, it is a Delco alternator, used in some GM vehicles - but don't waste your time trying to rebuild it - parts aren't available).

That alternator is buried and right up under the block. Seal everything up in the engine bay with panels and such, and there is no way to cool that thing with air. Makes a lot of sense once you see how it all goes together.

I won't begrudge the dealers that quoted me $2000 to $2500 for the job either now that I know what it takes.

But it's not much more effort than anything else that you have to do on the front / lower part of that engine. It all has to come out to get access. So even replacing the serp belt (which of course I did) is an effort in and of itself.

But it gave me the chance to clean up a bunch of grease and grime caused by the left side turbo spitting oil. It was a project I'd been trying to get to for the last year after I noticed a lot of oil dripping on that side when I dropped the engine guard for another project.

Dealer say it is quite common and not worth fixing the small leak in the turbo that causes it. His advice was to clean it periodically by draining the inlet to the charge-air cooler and wiping up any mess that may have leaked out if that seal is bad (replace seal too). And then drive it hard so the oil gets sucked into the engine and burned rather than pooling in the inlet tube.

And I'll also clean both charge-air coolers properly now that they are out of the car.

And yes, luckily I had AAA with 100 mile range. Closest dealer was 99.2 miles from where I sat. That was the ONLY thing that worked out for me that day

Still 150 miles from home. Had to go up my truck with the biggest trailer I could find. If you want to tow your CTT, you'll need the 7500 Lb. trailer from U-Haul (have to search for it) and a tow vehicle that weighs at lease 6000 lbs. Another long story. Perhaps I'll start a thread about it.

And if your red battery light does come on, you have about an hour and a half before you are left stranded, so yes, it is time to panic!

JohnnyBahamas

Thanks for this thread. I learned a good deal of important stuff. I'm much more prepared now.

I've already found the sections I'm going to print off of the PIWIS shop manual system on the Porsche website in preparation for this event.

Thanks again.

johnarusso

More on proper crimping.

The connector kit Porsche sells for this project is made by AMP, a division of TYCO. It is a JPT series product. The pin is part 929940-6. It requires the AMP crimping tool 539635-1 and the die 539737-2. If you source a new one you will pay around $700 for this tool.

I found a used one for around $400 so I bought it. I am an EE so I will likely use it for other projects. I would not do this if I only had one crimp connection to make.

Anyone living in Norcal doing this project, contact me if you want to use my crimper. Otherwise, find something that will get you close and SOLDER it.

johnarusso

Johnny B.

You'll want document 272219 to start. It will point you to a bunch of others that you'll want to get, but that's the place to start.

Aside from the crimp issue, of which there is a work around, you will be draining and refilling your cooling system. That's a project in itself. If you do not have a vacuum bleeder, you might want to plan to have someone do a flush and fill.

I have a tool that allows me to reuse my old coolant. The dealer did the work when I replaced the plastic coolant pipes and I am betting they did not change the fluid, so it might be time. The stuff is expensive. You need about 10 liters at around $10 per liter.