2000 ALH vs. 2003 ALH

[1975 Kombi]

I currently have a 2003 Jetta with a failing ALH and was wondering if a 2000 ALH would be a direct fit on the electronic side of things. Or if there are any differences in the 2 motors. I was hoping to use the 2003 ECU and wiring.

 

[Fix_Until_Broke]

The only thing I can think of is that the 2003 injector #3 plug is a D shaped whereas all the earlier ones are 0 shaped.

There may be other minor things like that, but I believe they're all functionally the same.

 

[Nero Morg]

I've done that swap, put a 2000 engine in my current 2003, only thing you have to change is the 3rd injector connector.

 

[Metal Man]

The motor would be a straight forward swap. If you swap the ECU and wiring, that may complicate things.

Edit to add now I see I read your post wrong. I was thinking you wanted to put the 03 items in an 2000.

 

[oilhammer]

The only difference is the lift sensor connector on #3 injector (which can be depinned and swapped, the function is the same) and the glow plug circuit. 2000 still has a 2-channel ON/OFF glow system, 2003 will have the 4-channel duty cycled system. So the glow control unit is different as is the wire harness.

But the glow PLUGS are the same. So if you have a complete 2003 harness, you can attach it to the 2000 engine and it will work just fine.

 

[1975 Kombi]

Awesome thanks everyone. I will try and keep the 2003 wiring intact and just switch the #3 injector. Thanks

 

[jokila]

While the engines are the same there are differences in the things you attach to it. As already mentioned about the injector connector and glowplug circuits, depending on the transmission, you would might need to swap the configuration on the coolant flange to the back of the motor as it would have the coolant glow plugs.

If you are getting a long block much of this you would be reusing off of your engine anyway so it should be as simple as transferring the parts to the replacement engine. I would recommend you purchase new gaskets to make sure you don't have leaks putting this all together.

 

[Nero Morg]

Speaking of, if you have the flange for an automatic (composite plastic) you may want to order a replacement, as they like to deteriorate over time. Same with the thermostat housing.

There are small differences in the engines, such as the engine mount bracket hole is a bit beefier on the 03 block, but it'll still all bolt up the same.

 

[mrfiat]

Some of the early 2003s have the earlier #3 injector connector. (I have one of those) My other 2003 has the newer type of connector.