MkI Rabbit 1.6 D engine into a 85 Mk II Jetta

man630

New member
Joined
May 25, 2013
Location
oakley, ca
TDI
85 jetta
I’m currently running a 85 Jetta 1.6 NA with high mileage.I Recently found a running low mileage Rabbit MK I 1,6D engine for sale . Has 1.6D on the block and triple squared head bolts so I’m pretty sure it has 12mm headbolts? The main difference I see is the injection pumps are different . What’s the main difference in these 2 pumps? I also read somewhere the MKI engines have some weird motor mount configuration where you need to dissemble the timing belt to change out the mount to my MKIi motor mounts. The other difference is the crank gear bolt, my MKII is 19mm and the MkI is 17mm. I also recently found out there is big nose and small nose crankshafts (23mm vs 31mm) I assume the MKI has a small nose and my MKII has the big nose. Any issues with smaller crank in a stock 1.6na engine for reliability. Any info Appreciated. I’m just trying to decide if the MkI engine is worth dealing with or is it better to just rebuild my MKII engine.
Thank You
Randy
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis (where it's safe)
TDI
There are just too many to list....
You may find parts hard to source for certain things. But I would try and identify what is "wrong" with your engine before trying to go after something even older.

My '91 Jetta went 437k miles before it needed a rebuild. The solid lifter engines like your '85 should in theory last even longer. Abuse, overheating, and neglect are what kills those engines. They also have weak head gaskets. And unfortunately for the solid lifter engines you really don't have an option for any MLS upgrades that I am aware of.

In any event, A1 and A2 engine/trans mounting configuration is entirely different. So you'd at minimum need to swap all the brackets over from your existing engine anyway. Swap the pump and put a new belt and tensioner on while you are at it.

The ME engine in your A2 and the CR and JK engines in the A1 all use the same crankshaft, the M suffix part.
 

Mozambiquer

Vendor , w/Business number
Joined
Mar 21, 2015
Location
Versailles Missouri
TDI
1998 VW Jetta TDI. 1982 VW Rabbit pickup, 2001 VW Jetta TDI
Personally I'd rebuild the one you have. Low mileage 1.6 idi may mean stuck rings, that was a common issue if it sat too long. I rebuilt a few 1.6 engines, and they're not very hard to do.
 

man630

New member
Joined
May 25, 2013
Location
oakley, ca
TDI
85 jetta
Thanks for the reply’s. My engine is still running fine but getting pretty bad blow by. I’m just planning ahead to rebuild this engine or keeping an eye out for rebuilt ones. This A1 rebuilt has pretty extensive documentation. Changing out the mounts should be pretty easy. The cooling system hoses also look like they are configured different. My main concern is the different injection pump on the MKI. The newer MKIi pump has different timing advance from what I recently read. Output is supposed to be pretty similar in the 2 pumps? Would the MKI pump work and as is if swapped into to my 85 with the MKI Engine? It was also rebuilt recently.
Photos MkI and MK II pumps
 

man630

New member
Joined
May 25, 2013
Location
oakley, ca
TDI
85 jetta
Photos
Thanks for the reply’s. My engine is still running fine but getting pretty bad blow by. I’m just planning ahead to rebuild this engine or keeping an eye out for rebuilt ones. This A1 rebuilt has pretty extensive documentation. Changing out the mounts should be pretty easy. The cooling system hoses also look like they are configured different. My main concern is the different injection pump on the MKI. The newer MKIi pump has different timing advance from what I recently read. Output is supposed to be pretty similar in the 2 pumps? Would the MKI pump work and as is if swapped into to my 85 with the MKI Engine? It was also rebuilt recently.
Photos MkI and MK II pumps
Currently having issues trying to upload photos
 

Mozambiquer

Vendor , w/Business number
Joined
Mar 21, 2015
Location
Versailles Missouri
TDI
1998 VW Jetta TDI. 1982 VW Rabbit pickup, 2001 VW Jetta TDI
Thanks for the reply’s. My engine is still running fine but getting pretty bad blow by. I’m just planning ahead to rebuild this engine or keeping an eye out for rebuilt ones. This A1 rebuilt has pretty extensive documentation. Changing out the mounts should be pretty easy. The cooling system hoses also look like they are configured different. My main concern is the different injection pump on the MKI. The newer MKIi pump has different timing advance from what I recently read. Output is supposed to be pretty similar in the 2 pumps? Would the MKI pump work and as is if swapped into to my 85 with the MKI Engine? It was also rebuilt recently.
Photos MkI and MK II pumps
You can swap the pump between the two. And the mounts will swap as well.
 
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