//// ALH TDI into 2005 Dodge Gran Caravan ////

Hi All,

My Caravan's 3.8 V-6 is starting to burn a little oil so I figure it may be time to start looking for a solution .... It's not burning or leaking alot and the rest of the van is in great mechanical shape despite 336K mostly highway miles (well mostly highway since I got it about 150K ago).

I know other caravans have been done but I think they were earlier models and or they used the 5 speed from the Jetta.

My preference is to actually use the existing automatic in the Caravan because :

1) automatics are easier for other people to drive ... not everybody can drive a stick and I don't want them learning on my vehicle!

2) The gearing of the trans seems to be well suited for the TDI engine .... I will know more for sure after I install my Scan Guage II but looking at the tach and GPS speedo, it looks like the gearing is such that the TDI is spinning fewer RPM's at speed .... Almost like changing out the 5th gear on our 5 speeds for lower engine RPMs at speed (I'll try to see what engine speeds are in other gears but I have not done that yet).

3) I'm thinking making an adapter plate for the engine / tranny and output shaft converter is easier than trying to graft in the TDI / 5 Speed and worrying about welding up the CV Axles ...

Also since the van is heavier than the Jettas, the weak link would not be the smaller (presumably weaker) jetta tranny / shafts.

5) I'm thinking the Caravan tranny may be computer controlled (have not researched yet), but I'm thinking all I have to do is figure out what sensors are on the engine of the dodge and rig them up onto the TDI engine (hopefully there is a mechanical / optical sensor of sorts to read engine RPM etc).

6) The V6 engine has a manual throttle cable so it would be easy to use the TDI throttle to control the TDI engine.

7) I'll use the engine accessories off the minivan (AC compressor , Alternator, PS Pump etc ) since they are already sized to handle the larger volume of the interior (well at least from the AC standpoint).

8) I'm thinking custom pipes to keep the stock caravan radiator.

9) I'm assuming I need to find weaker front springs since the TDI may weigh less than the 3.8 V6 but I'll have to research that ( on the flip side people often install VR6 springs into jettas so maybe keeping the factory stock springs will be OK?

10) custom motor mounts would be needed

11) I'm thinking I need to keep the guage cluster from the TDI and use that instead of the caravan's guages?

12) I think a return fuel line would nave to be plumbed in to the fuel tank ... BUT the electric fuel pump should be a plus feature to ensure fuel to the injection pump (no more air bubbles in the fuel line!) and easy to prime in case fuel runs out

What do you think? Anything else to think about?

I'm wondering how the preformance / MPG s would be ?

Any input would be appreciated.

Thanks

Andrew

I think that sounds like a good swap.
We used to have a first gen caravan with a Mazda RF Diesel engine from a Ford escort. It was turboed, but not tons of power and it did pretty good so I think an alh would do a lot better.
Hope you have fun!

Sent from my S60 using Tapatalk

Anything ever come of this? I have a 2008 town and country that's in the same boat but has the 3.3 in it. I was looking, around, and as you described I'd prefer to use the stock transmission. But I thought about doing a mechanical pump engine, still turbo but no engine electronics. Then you could tap in anywhere you need to make the dodge components happy. And less stuff to go wrong. I'm thinking the stock radiator will flow to much too fast at least mine will I believe because it has 3 zone heating. Definitely curious about this, but as you've said I've only found people who have swapped a complete drive train

The caravan only weighs about 500lb (not loaded) more then the beetle. I've pulled ~1200lb behind my beetle before amd have made some hard pulls even though I generally drive nice when pulling. I haven't had an issue. The tdi manual transmissions are pretty sturdy. I imagine it would be easier to convert to a manual trans rather then try and get the tdi to run with the vans auto tranny. That auto isn't made to drive behind a 4cyl, much less the power band of a diesel so its gearing and shifting will be way off unless you change that. If you really wanted to you could do that mod that allows the 5th gear to get more oiling, but generally as long as you have sufficient oil in the trans your good to go. Stick with stock gear oil or maybe slightly heavier.

As others said, the idea of using the Chrysler trans behind the TDI would be difficult at best. The trans is electronically controlled and relies on inputs from the engine. Someone clever enough and with enough effort could probably find ways to fake all that, or use a standalone trans controller of some kind, but it would be big work. And even then some of the trans' physical characteristics, like TC stall, might not be a good match for the TDI.

Probably easier to ditch the Chrysler van and either do a more compatible TDI swap into a Eurovan if you want a TDI FWD minivan, or trade money for time and just spend the bucks to get a SWB Sprinter or Powerstroke Transit or other reasonably efficient factory setup.

89vr6 said:

Anything ever come of this? I have a 2008 town and country that's in the same boat but has the 3.3 in it. I was looking, around, and as you described I'd prefer to use the stock transmission. But I thought about doing a mechanical pump engine, still turbo but no engine electronics. Then you could tap in anywhere you need to make the dodge components happy. And less stuff to go wrong. I'm thinking the stock radiator will flow to much too fast at least mine will I believe because it has 3 zone heating. Definitely curious about this, but as you've said I've only found people who have swapped a complete drive train

Click to expand...

Hi,

I had researched more into this but then I got busy with work and ended up getting and driving a full sized van since the additional size was needed.
(I continued to drive the caravan tho as is and ended up putting on an additional 90K miles on it so far).

The mechanical ALH would probably help make the install much easier but I read that its the electronics that helps the engine achieve the great MPG and power .... not sure how much advantage the electronics gives in termas of MPGs and or power but maybe somebody else can chime in on this).

I see your point about the larger cooling system potentially causing overcooling but in the few other builds I have read about (even in non caravan swaps) I cannot recall ever seeing people haveing issues with overcooling .... maybe the engine working in a heavier vehicle helps with that issue?

Andrew

Your mpg's would decrease, but your also putting a 4cyl into a van so it's going down one way or another in comparison to a jetta. Though electronics would probably help the drop not be quite as bad.

Thats what a thermostat is for. Theres no overcooling...