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It is my first post here and I have a question, My car needs an alternator and the Original is not available in stock at the moment, a friend has advised me to install VW replacement, but before doing so I would like to be sure about it.
Original part number is
07C903021J
and VW part number is
07C903021K
Would that be possible to replace it with the mentioned part number above.
Common ticking time bomb on the W12 ( all variations) .
its a $3 o ring there are two for the water coolant feed pipes .The rubber perishes with time and thing sweeps out of sight .If it’s left fluid eventually finds its way into the alternator and with inevitability kills it .
I would get the proper J part because you need compatibility with the pipe threads and alternator body .
For those wondering how big a job ......the front has to come off and ideally radiator removed , but it can be swung to one side to get to it .
You need a guy familiar with W12 ,s and small hands to get to the rear oklier clips on the pipes .
some pics ......paint a 1000 words . From a VW forum but Bentley is the same principle .....best I could find to illustrate.
Front off , rad disconnected / drained and swung away ....still some bits to remove to access the alternator.
Bentley one bolt holds the O rings in place with a flange ......that’s all ! .....it eventually ends up leaking . See them both here under the flange These will leak .Not if ....WHEN ! O rings a peanuts a $3 part One 16 mm thread the other 17 mm Not sure which is which ....so make sure you buy the right part .
My radiator has been replaced as it’s an 04 car and eventually corrosion gets the better .....how ever while out my tech ( while in there ) elected to remove the alternator.......and guess what ......no prizes .....weepy / leaky rear o ring .....God bless an experienced B W12 guy .
Also replaced the serpentine belt and the idler pully (s) while “ in “
The belt is a 10 yr service life part anyhow .
Last edited by John Fiammetta; Nov 27, 2019 at 02:08 PM.
Common ticking time bomb on the W12 ( all variations) .
its a $3 o ring there are two for the water coolant feed pipes .The rubber perishes with time and thing sweeps out of sight .If it’s left fluid eventually finds its way into the alternator and with inevitability kills it .
I would get the proper J part because you need compatibility with the pipe threads and alternator body .
For those wondering how big a job ......the front has to come off and ideally radiator removed , but it can be swung to one side to get to it .
You need a guy familiar with W12 ,s and small hands to get to the rear oklier clips on the pipes .
some pics ......paint a 1000 words . From a VW forum but Bentley is the same principle .....best I could find to illustrate.
Front off , rad disconnected / drained and swung away ....still some bits to remove to access the alternator.
Bentley one bolt holds the O rings in place with a flange ......that’s all ! .....it eventually ends up leaking . See them both here under the flange These will leak .Not if ....WHEN ! O rings a peanuts a $3 part One 16 mm thread the other 17 mm Not sure which is which ....so make sure you buy the right part .
My radiator has been replaced as it’s an 04 car and eventually corrosion gets the better .....how ever while out my tech ( while in there ) elected to remove the alternator.......and guess what ......no prizes .....weepy / leaky rear o ring .....God bless an experienced B W12 guy .
Also replaced the serpentine belt and the idler pully (s) while “ in “
The belt is a 10 yr service life part anyhow .
Thank you for your reply, my alternator is burned and have to be replaced, due to lack of dealers here, I can not find OEM part, so as mentioned earlier I have to replace it urgent, and wondering if this part would fit 100% - 07C903021K.
They look identical except for the nut next to the plug, your help is really appreciated
Thank you for your reply, my alternator is burned and have to be replaced, due to lack of dealers here, I can not find OEM part, so as mentioned earlier I have to replace it urgent, and wondering if this part would fit 100% - 07C903021K.
They look identical except for the nut next to the plug, your help is really appreciated
Having never had a "K" in my hands, all I can suggest is for you to take your original "J" unit with your to where ever you are picking up the "K" unit and physically compare the two side by side to check all mounting areas, hose connection alignment, electrical connection, and so on, that's all I can offer without having both here to compare, the both are 190 amp units.
Having never had a "K" in my hands, all I can suggest is for you to take your original "J" unit with your to where ever you are picking up the "K" unit and physically compare the two side by side to check all mounting areas, hose connection alignment, electrical connection, and so on, that's all I can offer without having both here to compare, the both are 190 amp units.
Johnny
Thank you for your reply, Right now I haven't yet removed the "J" unit but I have the "K" unit in my hand, they look identical 190 AMP - 14V, except for the position of the plug and B+
The reply from John Fiammetta pics have the same unit but with manufacturer number LR1190907E, Any one think the B+ position will make a problem ?
Why not post some pics of your K unit , so we can see / cast a reasonable opinion if it will fit .
My concern is it’s universal part across a wide range of VAG cars ......but has different cooling pipe connections .
Some are individually threaded in tightened by a bolt , either 17 or 16 mm thread , others have that central plate like the a Bentley variant where the pipes are held one centrally placed stud .An o ring keeps the seal , pressed down by this plate .
Electrical connections looks identical , maybe diff positions buts that’s easy to get around .
Its the water pipe compatibility that’s the biggie .
As John F stated, post a picture of the K unit.
I for one think the B+ connection will be a problem if it is on the rear of the K unit, and not on the side as the original J unit, which most likely will have clearance issues.
Here are a few pictures of one of the J units I have sold.
As John F stated, post a picture of the K unit.
I for one think the B+ connection will be a problem if it is on the rear of the K unit, and not on the side as the original J unit, which most likely will have clearance issues.
Here are a few pictures of one of the J units I have sold.
...
The K unit is exactly as what was posted above, and here is a picture of it
Yes It’s a VAG generic part with various water connections and different electrical connections .
Looks like the water connections ( with a new o rings ) is identical.
Both electric connections are in different positions..... It’s very tight in there extremely tight needing considerable experience just to remove the existing alternator.
Interesting to find out how you or your tech gets on ?
Yes It’s a VAG generic part with various water connections and different electrical connections .
Looks like the water connections ( with a new o rings ) is identical.
Both electric connections are in different positions..... It’s very tight in there extremely tight needing considerable experience just to remove the existing alternator.
Interesting to find out how you or your tech gets on ?
Thanks for the tip, as long as the electric connections are the same, position will not be a problem with my mechanic i guess, also do we need to change the water connections cuz of size or my pipes will fit well ?
Thanks for the tip, as long as the electric connections are the same, position will not be a problem with my mechanic i guess, also do we need to change the water connections cuz of size or my pipes will fit well ?
Hello Shaqovic,
I am not sure you are following the comments here, being the electrical B+ connection is in the wrong place on the K unit, your mechanic is not just magically going to move it or make it work, if the area is as tight as I believe it is, do NOT allow your mechanic to add a wire, or run your original B+ cable to that area, you most likely later on down the road will end up with the cable rubbing through and causing a fire, you should be getting the correct "J" unit, I mean you have already spent 7 days here guessing if it will work...
Please do not take offence to my comment, but I would hate to see you come back here with a worse off issue after trying to fit the "K" unit.
Hello Shaqovic,
I am not sure you are following the comments here, being the electrical B+ connection is in the wrong place on the K unit, your mechanic is not just magically going to move it or make it work, if the area is as tight as I believe it is, do NOT allow your mechanic to add a wire, or run your original B+ cable to that area, you most likely later on down the road will end up with the cable rubbing through and causing a fire, you should be getting the correct "J" unit, I mean you have already spent 7 days here guessing if it will work...
Please do not take offence to my comment, but I would hate to see you come back here with a worse off issue after trying to fit the "K" unit.
Johnny
Hi Johnny,
Nothing taken This is my only time will own a Bentley and still it's only 61,000 KM, I have and had many super cars from different names and never faced what I have faced with Bentley, now believe me I will sell it ASAP.
I will advice my mechanic not to do any modification, should it fit as it is or will have to buy the J unit unfortunately
Will work on the car next week and get back to you with the updates, fingers crossed it will fit some how
Thanks for the advice and I always welcome infos and tips from more experienced people like your self
