Discovery 2 diesel conversion - UPDATED FEB 2014

Lots of customers have asked if it was possible to convert a Discovery 2 to diesel, and until recently we suggested the only way to do it was with a HS2.8 (if you can still get them) or a Td5 which gets complex with wiring as they need their own ECU. And they were not very good anyway so better off fixing your old V8!

So we bought a nice clean 2000 Florida D2 with the common problem of dropped liners, to see if it was possible to fit a 300 Tdi into it, and what really needs to be done to make this work right.

Well, let me tell you it was a very interesting project and the learning curve was very steep, involving many hours of working out how each computer talks to one another, but we did it.

We took a standard 300 Tdi 5 speed and replaced the V8 auto very quickly indeed - as we know what to do with Discovery 1, (See here a D1being converted 5-6 years ago) this was the easy part, what was complex was getting the dash to work, the heating and A/C to work and the ABS.

The clutch mechanism would have been easier if we had a LHD pedal box but we made a pedal assembly, but I guess a D1 would fit quite easy - if you can find one!

The engine and transmission work well - a little under powered compared to a V8, but quite driveable in standard form - we will make some tuning upgrades to the Tdi in the near future, but for now we will keep it standard.

I would not recommend the 300 Tdi auto as a conversion without significant changes to the gearing as we did with the D1, which makes it a whole lot more driveable, but not so good on fuel as they should be, be as we run on veg oil this is not an issue for us.

Converting a D2 Auto gearing is going to be a complex job - doable, but I cannot see it being cost effective.

The 5 speed give good control of the engine power and because we used the D1 5 speed, we also have a diff-lock which is fitted in the early D2 transfer cases, but not linked up. Fortunately the SLABS control works as it should do and the traction control is great - I tried towing the car trailer in deep snow and was very impressed and found the diff lock was not needed - but nice to have!

There are no modifications to propshafts or any other parts - you can even use the original tail pipe so nothing looks different on the outside.


This is a temp picture to show how neat a conversion looks - I will get more now the A/C has been hooked up

So what will work?


So will we be doing kits?

Well, sadly no and the reason for this is you really need to have a T5 or Rovacom to access the computers to change settings - there are some who think that simply ripping out the LED's on the dash is enough to stop the crazy lights coming on, but that was not good enough for us - we wanted it right. You have to trick the engine computer that the old V8 is still there, once we worked this out then a whole lot of problems disappeared at once.

I think someone with no fear of electrics will have a good time fitting the 300Tdi to a D2 - the actual mechanics of the job is pretty straight forwards, but because the wiring needs significant modification, it is impractical to offer a kit or instructions to do the conversion at home, and paying a mechanic to figure this out would wipe out any savings.

The 300 Tdi for a Discovery 1 are very affordable in the UK right now, and hence makes the job worthwhile. We do strip most of the engine down and replace belts and seals first, we modify the clutch and strip and check the transmissions before fitting. As modified new heads are affordable, we replace them and the gaskets to suit.


We would be interested to do another, but only if the customer comes with the car, but I cannot see us getting the ACE to work as there is not enough room on the 300 Tdi to fit the hydraulic pump, but until we have a go then we are going to err on the side of caution.

So to sum up, you can retain all the comforts of the D2, the drivability and the looks. We are getting good fuel mileages so far, but hard to give accurate figures as it is winter now - watch this space.

Personally I think it was a good conversion - I do not like computer controls, but to get the dash to work you have to have them, BUT the 300 Tdi itself has no computer, so this means this tried and trusted engine will go the distance without expensive repairs and constant fears about loosing water etc. From now on all our 300 conversions come with brand new heads (not recons), heavy duty head gaskets and brand new radiators. The idea is to fit and forget - keep the oils changed and used good fuel and you cannot go far wrong. So in the event of a computer or wiring failure, the 300 Tdi Can be hooked straight to the battery with one wire to get it running - and you can push start it!


I did see someone on the web put an Isuzu engine in a D2 but it looked a bit of a mess and I didn't like the way the transmission was mounted, but I would like to do and Isuzu to the R380 gearbox in the future -if I can get hold of one.


One of the main reasons for doing the 300 Tdi was they are generally very reliable, cheap to buy and there are plenty of spares for them all over the world. They are easy to work on and maintain by even the most basic garage


February 2014 - update


Well, this car has been running faultlessly for the last few years and it was a good test.

We are still getting many enquiries for conversions and we think we may have come up with a solution to make the 300 Tdi fit easier and talk to the engine ECU in a less complicated manner whilst retaining all the features working - this is still on going so keep coming back.

We did an experiment on a D1 with an automatic 300Tdi by changing the transfer gears and it made it a lot better for driving about town, but on the highway it lost out a bit on MPG, but has made us think that it may be possible to make an auto 300 Tdi using the original transmission. We really need another car to practice on!

Although engines in the UK are becoming more available, the exchange rate has jumped and also shipping prices for kits has gone bananas, so we are back at the same problem - making this cost effective.

Times are changing and the D2, although being a very nice car once you get rid of the V8, is getting old now, and the economics of fitting a diesel make it a tough call.

Personally I would have nothing else, but we do not pay ourselves for all the time we put in for converting a vehicle, but when it comes to a customers car it is a different matter.

One other thing that has been a stumbling block is the possibility of doing a kit for DIY use - you need access to a programming computer to reprogram the body computer if you want to fit a 5 speed - so you can see our train of thought about retaining the autobox as this makes fitting very easy BUT until we do one, then I cannot give it a green light at the moment - things that work out on paper are not always practical!

There is no way to get the ACE on the 300 Tdi without a lot of work, and frankly the car we converted had no ACE, it handles very nice on STD swaybars, so the ACE could be removed and STD parts fitted in place - these are not too expensive, but add another layer of expense.

Keep checking back and there may be some updates in spring - we are always looking out for D2's that have busted v8's

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Revised: February 19, 2014 .