Importing a used Diesel motor to the USA for a Toyota Previa

Yes, you can probably import a diesel motor only. However, to convert the Previa into a diesel-engine vehicle, you would need at least a new fuel tank, fuel filler neck, fuel pump, fuel lines, transmission, ECU, transmission ECU (if you have an automatic transmission), brake booster if the engine does not include a vacuum pump, and engine wiring harness. You will probably also need a new dashboard wiring harness, ignition switch, instrument cluster, and cooling system. If the engine does not include a starter, you will need a new starter. After you spend somewhere in the vicinity of $10,000 to $15,000 to convert the vehicle, you probably will not be able to pass any emissions tests or get it repaired.

Ray,

Assumptions.... Thought the rest of the vehicle would be compatible as is.... oh well.

Not as simple and clean as it was in my mind... ;)

Thanks for setting the record straight.

-Matt

A proper conversion to Diesel is a huge job that basically involves swapping the engine and powertrain.

I have to agree with Ray - It sounds simple to "just do an engine swap" at first, and 25 years ago it was actually fairly easy to do.

But when the car is a modern fuel-injected emission controlled car, and you sit down and look at all the little details that are involved in getting to a finished car that drives right and (Most important!) that you can get smogged and registered every year to drive on the streets, suddenly it's turned into a HUGE project.

Transmission bellhousings don't mate up and you can't find an adapter (Custom machined bellhousing = big buck$), the stall speed on the torque converter is all wrong, the Transmission ECU freaks because they are made to talk to a gasoline engine ECU, the final drive (rear end) gear ratio is all wrong and you have to swap the ring and pinion, the transmission shifter linkages don't mate up, the driveshaft needs custom shortening and rebalancing...

It gets down to stupid little things - diesels have no usable manifold vacuum, you have to either change the power brake booster to a hydrovac system or add a mechanical vacuum pump to run them. And there's no ignition system to get a tach signal from, so you have to change out the tachometer module in the instrument cluster.

Diesels need a LOT more radiator cooling for the same engine size, and you'll have a heck of a time importing the right radiator now and every time you need a replacement. Or you'll have to have a totally custom radiator built which costs a small fortune.

Diesels need a LOT more battery to crank them over when cold - you need dual batteries. Do you have a place to mount them? And the oversize 1/0 battery cables to the starter? And you need a much larger alternator to recharge them, and a heavier electrical harness connecting them all together. Do you want to make a total custom wiring harness?

That's why it's a whole lot easier to buy the car built the way you want it. The auto manufacturer has the resources to solve all those myriad problems and deliver you a well engineered ready to use vehicle at a fair price.

You can still build a true custom, but after you get through leaping all the hurdles you're going to pay dearly for the privilege.

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