VW TDI Diesel Sahara

TDI Sahara

TJ Enthusiast
Nov 27, 2019
Saskatoon, Saskatchewan, Canada
I am new here but figured I would share a little hobby and project of mine. It is a 1999 Jeep TJ Sahara with a 2002 VW ALH diesel swap. I have the Dana 30/35 differentials with 3:73 ratio and AX15 transmission. Jeep is all original other than 31" BFG all terrain tires. It seems to be great little combination and I average about 35MPG.

If that's the case then I would suggest doing the diesel swap purely as a hobby. It will take quite a bit of time to pay back the expenses of the swap without doing long distance travel or towing. I commute with my jeep in the summer and put on about 60 miles a day, which isn't much but the increased economy is very nice.
I love it. I got my TJ originally to do a TDI swap. I wavered around looking at all kinds of swaps. I ended up with the R2.8 though, because I was looking at brand new and the kit availability was pretty good. I also prefer as much displacement for a diesel as possible.

I have another YJ and the TDI is probably the top candidate for the swap, but the Kubota swap looks like a lot of fun and I love the idea of the newer geared engines that are still mechanically pumped. However the TDI has so much more availability and you just need to be aware of your belt changes.

You gotta post more on this swap. I need DETAIL. Did you do anything to assist the timing belt swap in the future?

I've got a buddy that has several of these engines and he's looking to do a few swaps and 1 should start in the next few months, but he's got to get a few parts from Europe before he can start.
I am going to work on more detail for this swap as time goes on. I didn't take a lot of construction pictures but I have a few that I need to gather up.

I am jealous of your R2.8 cummins but I would say that one advantage to the TDI is overall availability. The 1.9 isnt a power house but it gets the job done for me and I like the compact nature of it.

I replaced the timing belt before installing the engine, but doing the job in the jeep shouldn't be a problem either. The biggest issue is that I don't have a timing mark on the transmission to correlate the crank to TDC. There is however marks on the harmonic balance that can be used. People will argue that the balancer marks are not as accurate but I did it this way the first time and all is well.
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The 1.9s are capable of very good torque, but the more hp per displacement adds additional stress if your right foot beckons it for all engines, especially diesels.

The TDI will totally be able to handle 160 HP.
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I love it. I'm not sure what's required to make 160 HP safe for these, but I do think there's guys running like 190/200+HP in semi-streetable setups. I would definitely do head studs and anything else before I went through the trouble of bigger turbo and injectors.

Some setups with bigger vehicles can benefit from more hp or gearing so the skinny pedal doesn't get too worn out, but I've never been big into modifying diesels personally, since I'm more interested in torque and most diesels have quite a bit of torque available. However with a fair amount of tools and gear, a TJ with around 300 ft/lbs is ideal, but even 240ish ft/lbs down low, with a bit more gearing would be totally acceptable as well. Honestly over 300 ft/lbs and I'm starting to worry about breaking stuff, so then you've got to think about a transmission and mating t-cases, length of driveline, etc and that gets expensive, though it's still cool.

What's the max safe RPM for the ALH?

A guy I work with has several of the TDIs from the generation before the ALH and he's got a van swap coming up and then he's going with a Toyota truck build when he can get to it. I am definitely torn on my next swap I want to do. There's about 4 engines I'm really interested in. This time around though I'm not going to be constrained by time like I was with my R2.8 Swap and that's a MAJOR reason I did that swap, because of the specs of the engine and the availability of kits with new good parts. The TDI was high on that list, but the way I needed to do it, the cost was only a bit cheaper, by the time I found the engine, had it built and bought a kit, I was in the same $$$$ window as the crate engine with Axis kit. At that point a couple grand wasn't a significant hit, compared to the slight advantage I saw to the R2.8 specs of a brand new engine vs TDI.

If you've got the time the TDI and Kubota, look like really really good swap engines:

TDI Pros (vs Kubota):

AVAILABILITY, Swap advice and history, support, price (probably)

Kubota Pros (vs TDI)
Geared timing, mechanical injection (could be considered a negative, but not so much for a swap IMO), displacement, unique (this is certainly a pro and a con, but if and when it works it's a major pro)

I love all the swaps though, but I really think the diesel swaps fit the needs for most Jeeps the best and each have their own advantages and disadvantages that it's just a preference thing for the most part, since we don't get a say with how the TJ should have been equipped.
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My TJ has a return less fuel system meaning that the fuel is returned to the tank directly at the fuel module/regulator. I completely removed the fuel pump and made my own bulk head connection out of a piece of plate, 3/8" copper line, brass fittings. The TDI needs a return line from the injection pump
I always go to this tangent, but have you ever messed with fuel pickup and return via a sump configuration?

Also, I'm just trying to remember, is it zinc that you want to avoid with diesel fuel? I was thinking that zinc in the presence of water could form something nasty, but I don't remember.
I always go to this tangent, but have you ever messed with fuel pickup and return via a sump configuration?

Also, I'm just trying to remember, is it zinc that you want to avoid with diesel fuel? I was thinking that zinc in the presence of water could form something nasty, but I don't remember.

By sump configuration, are you meaning to drill a hole in the bottom of the tank and add a auxiliary sump that has a threaded outlet port? I know the diesel truck guys install those but it would be a clearance issue for a jeep I imagine.

I have used copper line and brass fittings to repair diesel tractor lines before, no problem yet.