Local Copy - TDI Piston Info
Local copy of the TDI Club thread
1999 1999 AHU (A-3) engine # 101808 and above Cyl 1 & 2 038-107-065-AA (MAHLE) Cyl 3 & 4 038-107-065-AB (MAHLE)
1999 AHU / 1Z (A-3 & B-4) engine # 101807 and lower Cyl 1 & 2 038-107-065-D Cyl 3 & 4 038-107-065-E
1999 AHU engine # 101808 and above Cyl 1 & 2 028-107-065-BK (ALCAN) Cyl 3 & 4 028-107-065-BN (ALCAN)
1998 1998 AHU / 1Z (A-3 & B-4) engine # 101807 and lower Cyl 1 & 2 038-107-065-D Cyl 3 & 4 038-107-065-E
1998 AHU engine # 101808 and higher Cyl 1 & 2 028-107-065-BK (ALCAN) Cyl 3 & 4 028-107-065-BN (ALCAN)
1998 AHU (A-3) engine # 101808 and higher Cyl 1 & 2 038-107-065-AA (MAHLE) Cyl 3 & 4 038-107-065-AB (MAHLE)
1997 1997 1Z / AHU engine # 101807 and lower Cyl 1 & 2 038-107-065-D Cyl 3 & 4 038-107-065-E
1997 AHU (A-3) engine # 101808 and higher Cyl 1 & 2 038-107-065-AA (MAHLE) Cyl 3 & 4 038-107-065-AB (MAHLE)
1997 AHU (A-3) engine # 101808 and higher Cyl 1 & 2 028-107-065-BK (ALCAN) Cyl 3 & 4 028-107-065-BN (ALCAN)
1996 1Z engine # 101807 and lower Cyl 1 & 2 038-107-065-D Cyl 3 & 4 038-107-065-E 1996 engine # 101808 and higher Cyl 1 & 2 038-107-065-AA (MAHLE) Cyl 3 & 4 038-107-065-AB (MAHLE)
A-4 ALH engine
A-4 ALH series 1999.9 thru 2003
Cyl 1 & 2 038-107-065-AA (MAHLE)
Cyl 3 & 4 038-107-065-AB (MAHLE)
Now here is where I'm a bit confounded: The AHU and 1Z engines both have the same block (028-100-090-TX) Both engines use the same crank (028-105-101-L) Both engines use the same rods (028-198-401-F)
The only thing I see different between these engines (1Z / AHU) are the pistons.
Early: AHU / 1Z (A-3 & B-4) engine # 101807 and lower Cyl 1 & 2 038-107-065-D Cyl 3 & 4 038-107-065-E Late: Cyl 1 & 2 038-107-065-AA Cyl 3 & 4 038-107-065-AB
The A-4 ALH engine uses the same connecting rods (028-198-401-F)
My questions are:
Ques. #1
Are these pistons the same but only different manufactures?
1998 AHU engine # 101808 and higher
Cyl 1 & 2 028-107-065-BK (ALCAN)
Cyl 3 & 4 028-107-065-BN (ALCAN)
1998 AHU (A-3) engine # 101808 and higher Cyl 1 & 2 038-107-065-AA (MAHLE) Cyl 3 & 4 038-107-065-AB (MAHLE)
Ques. #2
Are the pistons for the higher # series (101808 & higher) the same design but different manufactures? ALCAN ~V~MAHLE ? In other words are these pistons interchangeable?
Cyl 1 & 2 028-107-065-BK (ALCAN)
Cyl 3 & 4 028-107-065-BN (ALCAN)
Cyl 1 & 2 038-107-065-AA (MAHLE)
Cyl 3 & 4 038-107-065-AB (MAHLE)
Ques. #3
If you were rebuilding a 1Z or AHU of any series # (high or low) What is the reason you could not use the A-4 pistons (as long as you used all 4 of the same P/N AA & AB)? Cyl 1 & 2 038-107-065-AA (MAHLE) Cyl 3 & 4 038-107-065-AB (MAHLE)
Here are a few pics comparing a 1z piston to the Nural ALH piston. I put the Nural piston in every 1z/ahu/alh block I rebuild.
In the above photos the piston on the right is: Cyl 1 & 2 038-107-065-D Cyl 3 & 4 038-107-065-E
The piston on the left is: Cyl 1 & 2 038-107-065-AA Cyl 3 & 4 038-107-065-AB
The main differances being the placement of the top compression ring and the longer skirt on the early version.
This answers my question of interchangeablity (Thank you).
Now the question about "BK" & "BN" pistons...are these the same as the "AB & "AA" ?
But I thank you for posting the great photos.
