AHU vs ALH in a Ranger

I'm looking to swap a TDI into a 2002 Ford Ranger. I have a line on a 98 and a 2000 jetta. I've heard the wiring is a little trickier with the ALH, but I also heard they were a better engine. Does anyone have a reason to go with ne over the other, or is it pretty much a wash.

both have pluses and minuses....

AHU positives... has simpler wiring, no need for immobilizer defeat, cheaper/easier timing belt, has a steel oil pan that can be more easily modified, initial cost may be less

AHU/1Z minuses.... less torque than ALH stock....auxiliary shaft that could be troublesome, no VNT turbo, map is built into ecm, oil filter/housing may interfere with steering(lots of AHU folks have this issue)...maybe more difficult to source used parts

ALH positives... more torque stock than AHU/1Z, lots of these motors around, VNT turbo and external MAP (easier to upgrade) no auxiliary shaft, oil filter is up and out of the way(cartridge type), used parts more pletiful

ALH negatives... initial cost, wiring slightly more complex, immobilizer equipped (99.5 not an issue), expensive more complicated timing belt system, has aluminum oil pan that can be harder to modify, belt system is serpentine (more difficult to eliminate an accessory)

personally I prefer an ALH, you could say I'm biased ...I feel like it's a cleaner looking and better built engine overall and it has a really neat looking aluminum valve cover!!! and did I mention every ALH comes with free lifetime supply of candy and puppies?

you are going to look at what you have for clearances in the engine compartment, that may make your decision easier. The ALH has a vacuum pump and stuff on the back of the head that would create firewall clearance. Like jimbote said, oil pan clearance is a big concern, I had to cut mine (1.6TD but same as AHU) because I wanted to keep my engine in the stock position. There is a steel oil pan available for the ALH I never had one off so I dont know what you have to work with in there to modify the pan.

As for the oil pan there is almost no sense in changing it, the oil pump is chain driven off the crank and sits right down infront. So modifications to the oil pan are essentially useless. I had a ALH in a 97 ranger for 4 years until it dropped a valve @ 456,000 . I am currently buidling another one after having learned from some issues from the previous one. There is a link with some pics on here of my first one. Just search my name or td ranger.
As for my current one, I am starting with a 2006 ranger. I have the motor mounted and sitting on the factory ford mounts. I am waiting for a copy of the adapter plate as this truck will be built with copies of the motor mounts and adapter plate. Keeping the originals for copying for anyone who wants. I am going to have a website to follow and also will be making the mounts and plate available as a kit. I already know the mounts will be around $240 The plate copy hopefully this week. Send me an email at jneufel5@shaw.ca if you are interested in this kit.

ALH engine

I'm biased too!

Here's a nice looking ALH engine .....
Notice the coolant flange on the rear of the head.......that can be modified using parts from an old Rabbit Diesel engine or gasser. The Vacuum pump, right above, only extends back about 3 inches.


Below is the Turbo side of the engine (no Intake in place)


Below is the Timing Belt end of the engine


Below is the bell housing end of the engine

If you don't want to run a lower profile coolant flange with no glow plugs in it, then use the coolant flange from the automatic version of the ALH. I personally wouldn't use the older style flanges as they are smaller and not really designed to be a radiator pipe, their purpose was to be a cab heater pipe.

Thanks for the help, I'm going to pick up a 2000 Jetta this weekend.

LoneRanger, I might be intereted in those parts. Let me know what the adapter bracket will cost when you find out. You should post some pictures of what your brackets look like as well. I'd be interested to see them.

what if you ran a vacuum pump on the accessory drive and used the old pump drive as a tachometer clock run thru the firewall? And relocated the oil-pickup to the rear if necessary?

Hasenwerk said:

If you don't want to run a lower profile coolant flange with no glow plugs in it, then use the coolant flange from the automatic version of the ALH. .

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Agree. And, if I may ask, what are those heaters for, anyway?

weelsey said:

Agree. And, if I may ask, what are those heaters for, anyway?

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Coolant heater to warm up engine quicker. They don't seem to make a huge difference so I wouldn't go out of my way to include them if it makes life easier to leave them out.

Rockwell said:

Coolant heater to warm up engine quicker. They don't seem to make a huge difference so I wouldn't go out of my way to include them if it makes life easier to leave them out.

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My Ranger doesn't have these, and I wish I did, 'cause when it's -30C you'll want every little watt of heat you can get!

On my former VW camper I relocated this to the front. I took a 1" I.D. cast iron plumbing pipe that was about 6 inches long, the type that you can get the caps for. I drilled the caps and installed brass fittings that had the same OD as the heater hose. Then drilled and tapped the pipe to accept the glow plugs. It worked well. The issue with the Vanagon is that like all real sports cars - the engine is in the back so by the time the coolant makes it to the front it's cold! I had it so when the hot|cold leaver was all the way to hot it pressed a switch which grounded the trigger wires on the two relays, thus over-riding the ECUs request for heat - it was quite nice!

This will go into my Ranger this summer so I won't freeze this winter.

A note to those who are thinking this is a great idea. The automatic TDIs have a 90A alternator and the manual TDIs have a 120A alternator to make up for the current that the coolant glow plugs use.

I haven't missed the coolant glow plugs in my Ranger....much better heat than my Jetta.