Ok time to sort this write up, If you are planning on doing this job I would suggest getting someone else to do it if you can, and if this is not affordable prepare to take your time doing it.
1. Remove front axle mounting. This runs along the back of the engine across both chassis legs. Two bolts on the chassis, and three bracketed around the axle.
2. Unbolt exhaust at Manifold. There are three nuts which are Jap spec, if you loose these or they are no longer serviceable, you can use the nuts which hold on the intercooler as a quick fix.
3. Remove all bell housing bolts underneath, and if you can at this point remove the starter motor.
4.Bellhousing bracket. This bracket attaches bottom of the bell housing on to the side of the engine. You will see the bracket reach around the side of the Dip stick pipe, and has two bolts on the side of the engine which need to be removed.
5. Now you have access to to the sump. Undo the millions of bolts and gently prize the sump away. Before the sump can be removed completely you will need to dismantle the oil lift pipe. this has one bolt on the left hand side (always looking from the front) and two bolts which connect the pipe to the block. There is a paper gasket here which should be reusable, but the Terrano 2.7 engine has a 'o' ring in it's place. The pipe and the sump should now come away to the rear of the truck.
6.Now it's time to remove all auxiliary devices. Alternator can be removed to one side as can the power steering pump and reservoir after you have removed the battery. Cable tie the reservoir somewhere, or it will fall over and start leaking fluid! Intercooler and air filter pipes.
7.Remove the water pump and fan in one go, and then remove the rad incase of damage.
8.Fuel lines, accelerator cables, sensor wires and glow pug wire at the back.
9 Sling the engine back left and front right, there are two more bolts at the top of the bell housing, and two engine mountings either side. Your ready to take her out at this point, you might find it's worth taking the bonnet off in order to get the hight.
Now you have it out, you can begin to asses what you need to change over. The 2.7 block I have was not intercooled which meant changing the inlet manifold. I had no outlet manifold on the new engine either so I had to change that too. It was worthwhile for me to strip the block bare pretty much for the following reasons:
A:Rocker Cover as the intercooled version needs the filler to come up round the intercooler. No Gasket needed here as it comes away quite well and is made of rubber.
B:Inlet and outlet Manifolds. Change these gaskets just to be sure.
C:Water Pump as there was no pump with this new lump. New gasket here too.
D:Oil cooler. I had to change this as there is an addition to the 2.5 td engine which there does not seem to be on the 2.7. The 2.5 has an additional oil pump/Compressor fitted into the crankcase. This has a pipe which runs up into the oil cooler. The 2.7 version had no where to put this pipe so it had to be changed. Steel gasket here which can be saved.
Spot the difference:
E.Injection pump and Injectors. I decided to use the 2.5 pump to save on cost, Was advised to keep the injector which go with the pump by HCII which is what I did. He also advised to keep the timing exactly the same, so I measured the pump to the block and made a note of that measurement. Remove the crank cover for this undo the bolt on the crank, three nuts behind and a lower mounting. I used silicone to seal this later, no gasket required.
In order for the pump to power the engine sufficiently I adjusted the maximum fuel screw which is located under a cover here:
F:Crank Case cover and Backplate. As mentioned above this additional oil pump/Compressor. I describe it like this as it had another pipe which runs off up into the brake diaphragm.
Now time to remove the crank case cover remove all the cogs, don't worry about the timing as it is pretty foolproof. There are two bolts which come down from the thermostat housing, and a couple of seals which need to be taken care of. You will have to do this twice to swap them round, so practice first on the casing you don't want to keep. It's quite this alloy in places and will be rusted on where the two top bolts come through the casing. I had a hell of a time with the one off the 2.5 motor (the one I needed most!) and prising with screwdriver can easily damage the seal seat for the water channels. There are tow of these and I replace these seals just to be sure.
Crankcase and cranks off, you will now just have to remove the backplate. There is a large complicated gasket for this which you will need, and while your here inspect the crank seal too.
2.5 with additional oil/compressor
2.7 Without
G.Change the flywheel. The 2.5 has a thicker flywheel, and it might also be worth fitting a new clutch at this point.
H. Finally, the last gasket you need to change will be the sump gasket as it is unlikely it will have come off in one piece. When you have the block back in you will need to keep the oil lift pipe and the sump off the 2.5 in order to allow for the lower bell housing bracket to fit.
I. Oil filter housing. I have kept the oil filter housing off the terrano, but the filters are about twice the price. Wether you pay for extra filtration seems a little unlikely, so I might in future replace back to the cheeper 2.5 housing. It also then saves complications in ordering a new filter.
All is all quite a major mod but a necessary one in my case, benefits are better acceleration more pulling power and much better economy!!
The engine sounds nice and tight , and now drives like new again. Downsides are my wallet is about £700 lighter.
Hope this helps others anyway, If I was thinking of making truck up though I would consider buying a newer Navara d22 with a bust engine and put the Terrano idi in. Theres a thought!
Many Thanks for all the Help everywhere.
