The TDi family - repair and maintenance
The 200 and 300 TDi are not an especially difficult prospect for the competent DIY-er. Even a complete engine overhaul should be within the abilities of anyone with a bit of mechanical experience and some decent tools. Below I have listed a few of the more common jobs that you might want to undertake, and provided some useful hints and tips, based on the questions I am asked most frequently.
Oil and filter change - every 6,000 miles. Oil capacity is around 6.7 litres. These engines are old fashioned and not especially fussy about oil - a good quality 15/40 mineral oil will be fine. Look for an API classification of CH or greater - lower spec oils are not suitable for the high temperatures generated within the turbocharger and will tend to degrade and turn to black tar.
Air and fuel filters - every 12,000 miles. The fuel filter housing has a 10mm headed screw for bleeding, and there is a priming lever on the lift pump. Note that the priming lever will only work when the pump actuator ois on the heel of the cam lobe. You need to turn the engine by hand using a socket on the crank pulley bolt, while operating the priming lever until you feel some resistance. If you manage to turn the engine through two full revolutions without finding any point where the priming lever works, the linkage inside the lift pump has broken - not uncommon, and you will need to replace the lift pump. Pump the priming lever until diesel emerges from the bleed screw without air bubbles, then tighten the bleed screw.
Valve clearances - every 12,000 miles. Clearance should be 0.20 mm on inlet and exhaust valves. Set the clearances using the 'rule of nine': turn the engine until number 1 valve (counted from the front) is fully open, then check valve number 8: 1 + 8 = 9. Turn it further until the next valve is fully open - this will be number 3 valve, so you check the clearance on number 6: 3 + 6 = 9. Keep going until you are back to having number 1 valve fully open, at which point you should have done all eight valves. Look out for broken valve stem caps: if the clearance on one valve is very large, check the condition of the cap and replace if it has punched through. Make sure you replace the rocker cover gasket, half moon seals and the 'O' ring on the cyclonic breather (on the side of the rocker cover) to avoid oil leaks.
Covered in more detail here. Recommended change interval is 60,000 miles or 5 years for Defender, 72,000 miles or 6 years for Discovery. However, this depends on what the vehicle is used for. For vehicles used in dusty conditions or regularly subjected to deep wading Land Rover recommend that the belt change interval is halved. I have seen enough TDis with the timing case full of mud to think that this is sound advice. I would also recommend that on any 300TDi, especially one with the earlier tensioner setup, the front cover should be removed for inspection at 30,000 miles to ensure that the belt is not wearing against the tensioner shoulders.
Not difficult if you follow the workshop manual. You will need an angular torque gauge, and the head bolt tightening sequence must be followed precisely. Head bolts can be reused up to five times according to Land Rover, but should be replaced if they show any signs of damage or corrosion. Cylinder head should be carefully inspected for cracks especially between the valves, and checked with a straight edge for signs of warping. If in doubt, have it skimmed. If the engine has been pressurising the cooling system you might also want to have the head pressure tested for internal cracks. Use a good quality (Elring) head gasket, and ensure the faces of head and block are absolutely clean and smooth. The head gasket should be fitted dry with no sealant of any kind, and make sure you fit it the right way up... There should be a hollow locating dowel at each end of the block - these are quite brittle and often crack. Replace if damaged or missing.
If the head has been skimmed, ensure that you slacken off all the valve adjusters before bolting down the rocker shaft, otherwise valves might contact pistons. Be careful when doing up the front rocker shaft bolt as the thread in the head is much shorter than on the other bolts. Tighten the bolts progressively, half a turn at a time, to avoid the risk of breaking the shaft.
There are three different thicknesses of head gasket, market with one, two or three holes punched in the outer edge. Three hole is the thickest and most common. The correct procedure is to measure the piston height above the block at top dead centre for each piston, using a feeler gauge and straight edge, then select the appropriate gasket. If in doubt, fit a 3 hole gasket - the worst that can happen is a very slight reduction in compression which might cost you a couple of horsepower. Too thin a gasket and the pistons will contact the head when the engine gets hot.
On the Defender 200TDi engine, if you have removed the thermostat housing from the head, make sure you refit it BEFORE bolting the head down on the block. One of the housing bolts is completely inaccessible with the head fitted.
If your engine is leaking oil from the bottom of the flywheel housing, most likely the crankshaft rear oil seal has failed. On the 200TDi the seal carrier is built into the flywheel housing - on the 300 it has its own carrier which bolts into the block. Either way the flywheel will need to come off, which means either removing the engine, or sliding the gearbox backwards on a transmission jack to gain access. On the 200 the flywheel housing will need to be removed to allow the old seal to be knocked out from behind with a chisel.
200 seal fitting: Clean all traces of sealant from the housing, then press the new seal (ERR2532) in carefully, ideally using a hydraulic press. You will need a very large ring to distribute the pressure evenly - an old Defender 2.5 water pump pulley will do the job if you grind a bit off the outer edge to reduce the diameter. Don't try and knock the new seal in with a drift or blunt chisel - the outer casing is very fragile and you will split the inner lip of the seal.
Early 200 flywheel housings had a shallow recess around the back of the seal carrier and were glued to teh block with RTV sealant. This was soon replaced with a gasket which is fitted dry. If you have the early type of flywheel housing, Land Rover recommend using a gasket (ERR1440) and filling the recess with RTV sealant. The gasket tends to set hard and is very time consuming to scrape off the vack of the block - you need to remove every last bit to ensure the new gasket seats correctly. Good quality gaskets are grey on one side, brick red on the other and have beads of sealant already applied - use one of these, not the cheapo grey plain paper gaskets.
The new seal (whether 200 or 300) should have a plastic guide which fits over the end of the crankshaft to prevent damage to the seal. Make sure the flywheel housing (seal carrier on 300s) goes on square, and tighten the bolts slowly and progressively to pull the seal over the end of the crank. Once it is in place the guide will pop out and can be thrown away. Make sure the flywheel bolts are cleaned and coated with thread locker - otherwise oil will creep up the threads and contaminate the clutch.
These are simple, old-fashioned engines held together with lots of bolts, and can be stripped down to a bare block without too much trouble. Provided the cylinder bores do not have a wear ridge at the top, and the crank bearings are not down to the copper-coloured backing metal, you will often get away with just new piston rings and shells. Before stripping the bottom end, check that all four pistons protrude very slightly from the top of the block at top dead centre: If the crown of one piston sits slightly lower than the others, the connecting rod on that cylinder is bent (usually due to the engine taking in water while wading). Check that none of the camshaft bearings have moved (the oil holes should line up exactly with the holes in the block. Inspect the nose of the crankshaft carefully, ensuring that the keyways are undamaged, and check that the rear crank seal has not worn a groove in the crankshaft, which will prevent the new seal from sealing properly. The 200TDi uses the same crank as the old 2.5NA and TD engines, the 300 crank is different.
You will need a pair of guides to avoid damage to the cork 'T' seals when refitting the rear main bearing cap. I use a couple of pieces of steel angle, bolted to the block and bent out very slightly at the top. New piston rings need to be fitted the right way up, with gaps positioned as per the workshop manual. There is an arrow stamped on each piston crown which should point to the front of the block when the piston is fitted.
If fitting new piston rings it is important to use a honing tool or glaze-buster to break up the shiny glazed surface of the bores. Otherwise the rings will not bed in properly and the engine will burn oil. If new pistons are required the cylinders can be bored up to +0.020" - beyond this they will need to be fitted with steel liners to take them back to standard size. Crankshafts can be reground down to -0.010".
On the 200 engine it is important to make sure that the rear edge of the block stiffener is exactly flush with the rear edge of the block. The stiffener does not have locating dowels, so you need to use a straight edge and double-check the location before doing up all the bolts.
Make sure you fit the tappet slides the right way round (the forward facing side has an 'F' cast into it). Use thread locker on the oil pump bolts, camshaft retaining plate bolts and the camshaft pulley centre bolt.
Start with the basics - ensure that the injection pump timing is spot on, the pump and injectors are in good order, valve clearances correct, wastegate not sticking open, turbo vanes not damaged and no splits in any of the intercooler hoses. The 200 and 300TDi left the factory in a fairly conservative state of tune, and as many people have discovered, you can get more power by adjusting the maximum boost pressure and playing with the fuelling on the injection pump. Land Rover did pretty much this on the 300TDi with automatic transmission, giving 122 bhp against 111 for the manual version. There is plenty of information on the Internet which I will not repeat here. Just be aware that if you get it wrong, the consequences might be bad. I have seen a few engines with bore wear caused by overfuelling, and a couple where attempts to adjust boost and fuelling have actually left the engine producing less power than standard. Beyond simple tweaks you might be looking at an uprated intercooler for a few more horses: after that it starts getting expensive - gas flowed head, larger valves, bigger turbo etc.
Later 300TDis have exhaust gas recirculation to reduce emissions. This system can be problematic and tends to clog the air intake with oily carbon deposits. The engine will pass MoT emissions without it, so many people blank off the EGR valve on the manifold - kits are available to do this.
Almost from the day the 200 TDi was launched, people started fitting them into older Land Rovers. Land Rover themselves offered a 'TDi in a box' kit, containing a brand new engine and everything needed to fit it into a pre-1990 Ninety or One Ten, down to the last nut and bolt. One of my customers has a 1985 Ninety with a plaque under the bonnet showing it was thus converted in 1993 - that would have been a lot of money to spend on an eight year old vehicle at the time.
Whether you go for 200 or 300 power for your conversion will come down to two things - engine availability, and ease of fitment. A 200 will fit in place of any of the four cylinder Land Rover petrol or diesel engines, usually using the same mounts. A 300 will normally need new mounts to be welded on. Brief summary of what is possible:
Series II or III - Discovery 200 engine fits using the Series engine mounts, flywheel housing needs modifying to fit bellhousing. Disco turbo fouls chassis rail on 109 inch vehicles - use 300 turbo and manifold, or convert as a 200Di (non turbo). Defender 200 engine requires modification to offside engine mount: exhaust manifold fouls steering box on left hand drive vehicles. 300 engine needs new engine mounts welding to chassis, and flywheel housing swapping for earlier 2.5 NA or TD item. For 6 cylinder vehicles you will have to swap the gearbox bellhousing for a 4 cylinder one and fabricate new engine mounts.
Ninety / One Ten (4 cyl) - Defender 200 engine is a drop-in swap, Disco 200 needs flywheel housing mods and a fair bit of plumbing work (click here for details). Turbo on Disco engine may foul steering shaft on left hand drive vehicles. 300 engine needs new engine mounts welding to chassis, and flywheel housing swapping for earlier 2.5 NA or TD item.
Ninety / One Ten V8 (5 speed) - either use the 300TDi engine and Defender 300 TDi (R380) gearbox (will need new engine mounts) or fitting kit from M&D Engineering to marry the 300 TDi to the LT85 gearbox.
One Ten V8 (4 speed) - use 300 TDi engine with fitting kit from M&D Engineering, or else convert to 5 speed using Defender 300 TDi gearbox and transfer box - will need new floors, seatbox, transmission tunnel, gearbox mounts, propshafts, and new engine mounts fabricated and welded to chassis. Fitting a 200 TDi in place of a V8 is not easy if you want to keep the original gearbox.
109 V8 (Stage One) - 300 TDi engine with fitting kit from M&D should work, but I don't know anyone who has tried this.
Quick note on gearboxes: you might be tempted to use the 5 speed box from a Discovery, especially if you have bought a complete Disco as a donor. This is not easy. The Defender box is 'long stick' configuration with the gear lever well forward: the Disco box is 'short stick' and if you try to fit one of these to a Defender the gear lever will stick up through the middle of the seat box. Converting an LT77 or R380 gearbox from short stick to long stick configuration involves pulling the whole thing apart with the aid of various specialist tools.
The Disco transfer box on the other hand is pretty much a straight swap for the Defender. Most Defender transfer boxes are 1.410 ratio which works pretty well. Some early petrol vehicles, and many military One Tens, have a 1.667 box which is far too low geared for TDi power unless you are running absolutely massive tyres or do a lot of heavy towing in mountainous places. The Disco transfer box is 1.2 ratio. This gives much quieter and more relaxed cruising, but at the expense of acceleration and towing capacity. It works fine on most Defenders, but I would not recommend it for heavily laden One Tens, especially Station Wagons.