ScootCherHienie

That seems pretty obtuse when there are ~$50 "intelligent" battery chargers that can tell what type of battery is installed (AGM, wet, gel, etc.) it's charge state, and ideal "float" maintenance profile. If you can do that in a <$50 in a smart battery charger, you should be able to do it in a car, even an inexpensive car.

Next you'll tell me that only a BMW dealer can "register" a new battery in a BMW car

v10rick

Scoot you are correct, apparently the P Voltage gauge is very precise.





This is at idle, reads close to 15V at 1K RPM. It is pointing a needles width above the 14V hash mark.
The meter leads are connected to the jumper posts in the engine compartment.

Don't know the age of my battery, it was replaced by the PO.

Sorry about the view. It is correct on my desktop, but is rotated while dragging to this tread.
?

kino1161

Mine sits slightly below the "13" hash mark.

deilenberger

Who would'a thought that? And yup - or if you own an iCarScan - it can do it for less than one dealer visit.

kino1161

I must correct my earlier statement about my 12.8 remark. I was incorrect. Mine sits right at or slightly below the hash mark between 12 and 16 which would be the 14 hash mark. earlier I stated 12.8 as if the hash mark was 13....but the hash mark is 14. My apologies.

kino1161

I must correct my earlier statement about my 12.8 remark. I was incorrect. Mine sits right at or slightly below the hash mark between 12 and 16 which would be the 14 hash mark. earlier I stated 12.8 as if the hash mark was 13....but the hash mark is 14. So, I would guess mine sits at 14 or 13.8. My apologies.

ScootCherHienie

?!? None of the parts I looked at mentioned the V-8 Cayenne alternator being water-cooled... only the one for the Toureg diesel. And the photos of the part they have... you never know if it's just a generic "Hitachi" photo or whether it is the actual alternator you will get.

Any source for images of the "real" alternator in the 957 V-8 series ('08-'10)?

The only photo I saw did not look substantially different than a conventional alternator (size/shape) though it did seem a bit more "enclosed" with softer/rounder corners than most alternators... perhaps indicating a water jacket? But no obvious connection for hoses visible.

deilenberger

HINT: Look at the price. And yes - it's watercooled. Be hard to have a 1KW alternator that wasn't.

http://sgmarket.ru/alternators/94860302500.html

Or:

http://www.altstar.kiev.ua/index.php...00009&det=&rt=

Has the Hitachi/Volkswagon/Porsche crossover PN's. Same one.

Ya learn something every day eh?

ScootCherHienie

When I looked at Rockauto.com the first time, they had a remanufactured Hitachi alternators for around $230 with $50 credit for the core, so ~$180 final cost. But a brand new Hitachi alternator was over $800 and the Porsche dealer price is something like $1700 or $1800. Quite a bit of a spread there! Makes the remanufactured part look pretty darn attractive. They only had 1 reman alternator in stock the first time I looked. The next day it was gone.

I looked at the alternator photos in the links... interesting, it doesn't LOOK like I'd expect a water-cooled alternator to look... looks like a normal alternator. I assumed there would be fittings for water hoses going into and out of the alternator. Perhaps the water cooling system is "self contained" within the alternator so there are only electrical connections and mounting bolts needed when removing or installing the alternator... like a conventional alternator?

v10rick

If you search this forum you will find numerous complaints about P and other remanufactured alternators. The major complaint is a short lifespan. Its a a PITA to replace. Saving money on the part may result in a hefty labor bill in the end.

deilenberger

REALLY? I picked ones that showed CLEARLY the hose connections to the alternator.



WHAT in Dog's name do you think the part I circled in RED is?

I'd suggest you take it to a competent mechanic and have him fix/replace the alternator. BTW - the "rebuilt" ones you find at places on-line, or big-box stores are ones pulled off wrecks and given a coat of aluminum colored paint. That's about the extent of the rebuilding process. In the BNW world - these are infamous for being installed and either failing immediately, or very shortly down the road, usually at an inconvenient place at an inconvenient time. Going cheap on parts on a Cayenne usually doesn't pay off - the labor comes back to haunt you, plus the cost of flatbedding it home. IF you used a NEW VW part which cost less - that's fine, but big-box-store crappola? Not on my Porsche.

deilenberger

You know why the 2nd guy wouldn't offer to install the big-box rebuild? He doesn't want to eat the labor for replacing it when it quickly fails. He's been burned on this before.

I rather suspect that if you can't do $850 for a new alternator - then a Cayenne may not be the ideal car for your budget. This thread failed to convince you that the old one is any good (and I see no reason to doubt what the mechanic said - he tested it..) and you're looking for a bargain way out. It might be time to fix the alternator and consider a different vehicle. When you buy a vehicle used for a fraction of it's cost new - unfortunately - the repair prices and maintenance expenses remain at the cost associated with the new price. It doesn't magically become a KIA with a 10 year warranty.

v10rick

^^^Agree 100%^^^

There have been numerous threads from newbie posters who brag about their CTT purchase, with an MSRP of $140K, for 15% of the original price. Soon after they are crying about a $5K repair for what seems like a minor fault.

Pay the price for a new P alternator. If not you may repeat the process within 3 to 6 months.

ScootCherHienie

Took the longest trip with the Cayenne so far since getting it in June. Realized I wasn't looking at instrument panel volt meter correctly... for some reason I thought the bar on the right was labeled 14, not see that it is labeled 16 so the line half-way between 12 and 16 is 14, not 13 as I was thinking. So I'm getting 14-14.5 at 50-70 mph with A/C running normally. Running fan at highest speed, high engine-RPM, air conditioning at max, stereo loud (where the shop says they measured 12.8 v definitely makes the instrument panel meter measure as low as 13-ish (close enough to the shop's 12.8 measurement), but setting everything to normal restores 14-14.5 readings on instrument panel voltmeter. Drove probably 6 hours in 2-hour stints with the car parked in between driving stints for a couple of hours at a time. No issues with battery running down on this long trip so doubt the alternator is an issue for me at this point. Still trying to find someone who has Porsche Factory Service manual who can tell me where the alarm system backup battery is located and how much of a pain it is to get at it (and the size/number)... suspect mine (8 years old now) has a shorted cell that drains it in 24 hours or so, at which point it begins drawing power from the main battery, slowly killing the main battery over 4-5 days when the Cayenne hasn't been driven in that long.

v10rick

Congrats you saved yourself a bunch of $$$. The dash meter indicates the alternator is charging as it should.

You can search for the alarm backup battery forever because it does not exist. Who told you there is one, the tech who claimed the alternator is shot?

Some highly optioned Cayennes have a second battery in the tire compartment. Look there if you think yours is equipped with a second battery. Details on how it works are in this tread.
https://rennlist.com/forums/porsche-...-question.html

If the battery is draining while idle, for a few days, one of the many modules which are always hot is at fault. Consult a competent automotive electrician to isolate the cause.