Well you asked for it. Usual caveats apply...
First off, buy books and spend time reading them before you buy. Get Martin Hodder's 'You and your land rover defender 90/110' published by Haynes and the Haynes repair manual before you start.
I would get the best car you can, otherwise you'll be rebuilding it and cursing it. There will always be plenty to fix on an old Land Rover to keep you joyfully occupied, without major jobs to do. An old, but sound example from the 1980' or early 90's is going to be worn, which is a world of difference from past redemption. An honest runner might only cost another £500 compared to a cosmetically/superficially OK rolling wreck that's beyond economic viability. So check with care and don't feel rushed, but be aware that faults are inevitable...which is why they are so affordable.
What you don't want is a chassis that requires extensive repair, or even worse, replacement. Check the chassis for holes - get under it with a screwdriver and have a good stab and tap with a hammer ( the main chassis rails should 'ring' when tapped, not thud). Don't worry about the surface rust though, but do worry of it's covered in black bitumen which only has one purpose - to hide a nasty chassis. There will probably be some repairs to the outriggers, or expect some corrosion there. Having said that, my 90 hadn't seen commercial or farm use and had solid original outriggers. However the rear cross member on any Land Rover of this age will probably have been replaced, if it has check that it is on straight. If it hasn't been replaced, chances are it will need to be. The bulkhead is another problem area. Surface corrosion bubbling on the side of the bulkhead between the upper door hinge and vent flaps is a common sight. Holes above and below the door hinges are more advanced corrosion, but as long as the corrosion is not extensive both are a straightforward, if perhaps labour intensive to repair. If you can weld then no probs, if not, it'll cost £1k for parts and labour to repair/replace a rotten bulkhead. Peel back the mats and look at the foot well and door pillar for corrosion. Also check around the foot pedals, any holes here will need to be properly repaired before MOT time. The footwell may have rusted out too, but that is cheap to repair and less time consuming. Chalky corrosion and bubbling paint and peeling off the door bottoms and lower parts of the wings is common. This is caused by electrolytic corrosion (it's where the aluminium door skin meets the steel frame). Unless the skin is significantly holed or the door bottoms are crumbling away it's mainly a cosmetic issue, but will require attention at some point and is expensive to fix properly (£270 plus labour and painting per door). The rear door is likely to be in a similar condition to the fronts, it comes in two pieces and if the spare tyre is mounted on the back check the door hinges for wear.
On the test drive accelerate hard in all gears and slow down in them all. If it jumps out of any it's an expensive repair. 2nd gear has a reputation for weak synchromesh, if it's worn it'll be stubborn to engage, especially from cold. Strangely the manual gearbox up to 1994 (LT77) uses Automatic transmission fluid, unless it's a factory V8 - in which case it uses engine oil (LT85). More conventionally the transfer gearbox and axles use conventional EP90. If the gearbox has been filled with EP90 gear oil it will wreck the synchromesh and will necessitate costly repair (£500 plus labour), so it might be an idea to ask if the owner has personally changed the gearbox oil, and what grade they put in. If in doubt whip off the level/filler plug and look for red ATF.
Try the high/low lever and diff lock. The ratio shift may be a bit tricky indicating lack of use, but if the difflock doesn't work I'd invite the owner to get it working before sale, or knock £100 cos it can be a pain to sort. You won't break the driveline just testing it and it's not just a niggle, it is essential that it works for using the 4WD off road. If the gearbox is noisy at idle (rattles or a 'swishing' bearing noise like running water) the bearings in the box are very worn, or the clutch release bearing is worn and is best repaired or rebuilt. A clutch replacement costs about £100 plus 7 hours labour to take the engine out. The transfer gearbox will whine in all gears but should whizz, rather than howl! Although a noisy gearbox is unlikely to fail catastrophically, the noise can be a major annoyance when driving more than a few miles.
Engines - well from 1983 there was a petrol 2.3 litre and diesel 2.5 litre. Both are very poor performers, even by the standards of 20 years ago. The petrol engine was enlarged to 2.5l by 1985 (I think), it's quite thirsty though - in the old days Land Rover quoted MPG as 16.3 urban and 22.8 at a constant 56mph. The constant 75 mph figure is 'N/A' because you'll be lucky to get to that speed. In practice the fuel consumption is likely to be high teens. The speedo is likely to over read by 5-10%, so don't be fooled into thinking it's quick! Otherwise the engine is an old trooper and cheap to fix. The 2.5 diesel is another venerable design producing 63 bhp and returning about 27 mpg. The 2.5 Turbo Diesel in production from 1986-1990 is best avoided. Most have been rebuilt at least once because it is simply not up to turbocharging, and it is expensive to fix. The 2.5l petrol has similar performance, is easier and cheaper to fix, but will use another 45 litres of fuel per 1000 miles. Check the distributor and carb for signs of constant fiddling - they are prone to wear and if the engine is not running very well it's likely to be one of those at fault. The 3.5 V8 was used in the 90 from 1985, initially with 114 bhp, but then improved in 1987 to 134bhp. Fuel consumption is in the mid teens, but it's a flyer and a great engine. Open up the oil filler cap and check for baked hard flaky oil particles - indicating a dead engine. Tapping from the top end indicates a worn cam requiring a top-end overhaul), but thumping from the bottom is terminal. Factory V8's with their stronger gearboxes and front diff command a premium over other variants based on their rarity.
From 1990 the diesel 2.5 turbocharged direct injection (200 Tdi) was available, which is an altogether much better engine with 107 bhp and 195lb ft of torque. The price for these vehicles will be significantly higher than a 1989 2.5 normally aspirated diesel. From 1994 the 300Tdi was available, which again will add a premium. Overall a well kept 200tdi or 300tdi is a very good vehicle, but if it's out of your price range a 2.5/3.5 petrol or the 2.5 normally aspirated diesel are the only other engines worth considering.
The tiny fuel tank (Land Rover optimistically quote 12 gallons, but 10 gallon/45 litres is your average refill) is under driver's seat on 90, check for leaks, it's a real pain to extract and replace.
Make sure you run the nearside front wheel over a few potholes on the test drive, if the steering wobbles violently you know you have bushes, dampers, ball joints and swivels to adjust repair/replace. If the steering is inaccurate and the car requires constant correction - it's worn, Land Rovers did not leave the factory like that! Early examples are unlikely to have power steering, but should be easy to steer once on the move. Conversely, power steering that is finger-tip light indicates a problem with the pressure relief valve and possible damage to the steering box seals. Check for red fluid leaking out, any more than dampness is an MOT failure. Speaking of which I'd ask for a new MOT on it, at your expense - which will check all of those things. Give the brakes a good stab too, a seized piston will show up as pull to one side (so do this on a wide road!) Rear brakes are drums on the pre-93 ones and easy to maintain.
The ride is much firmer compared to a car - that's normal. But if the ride feels harsh, crashy and uncontrolled (as opposed to firm yet controlled) - that's the dampers at fault. I personally would never fit 'heavy duty' dampers to a 90 - the ride can become too harsh and the handling benefits are marginal over good oil dampers. If it leans to one side it'll need new springs; no hardship to replace but a set of 4 springs and dampers is £150. Only fit genuine or good quality springs as the budget ones cost pennies less and a are a false economy.
Have a look at the tyres, do the sizes and profile numbers match? Tyres of different sizes are a big no-no on a 4x4. If they have different circumferences the centre diff will be working all the time to compensate for the rotational difference, and you should budget for a set of decent tyres. Differently branded non-matching tyres are no major issue. Check the spare if it has one, pull the cover off it and budget for a replacement.
As for body styles there are so many. Hard tops (no windows or rear seats) are the most common - because they are the bread and butter of farmers and commercial users. There are pick ups, soft tops, truck cabs and Station Wagons and County Station Wagons (CSW's). These fetch a premium over hard tops, not because of the seats, but because they will almost inevitably have lead an easier life in private hands, or non-commercial use. A mistake is to discount a CSW on the basis that it's cheaper and easier to fit windows and seats to a hard top - it totally misses the point! This why a late 80's V8 90 CSW can fetch £4500 - light use, rare example. So do check the chassis number (see PDF attachment) to see what it was originally, this will tell you if it has the same engine and body style as when it left the factory. The chassis number is stamped into the chassis on the driver's side front rail. You may have to scrape back a load of gunge to see it - so take a wire brush with you. Land Rovers are big meccano sets that get chopped and changed very easily.
I would say in summary that if the fundamentals are right (chassis, bulkhead, engine, gearbox and driveline) it's a good vehicle. Everything else is a running repair and part of the fun. Please don't be influenced by fancy wheels, chequerplate, bullbars, auxiliary lights and window dressing that spruces up a tired old example. Also if someone has mucked around with the electrics I'd walk away unless you really know what you're doing. Do not rush into buying a Land Rover - time spent now will save you later.
And finally, if the owner says that it doesn't leak - it's a lie. They all leak and are equipped with a spider ex-works!
Post photos on here if you want specific opinions on vehicles you are looking at, and if you found this thread useful please rate it! Happy hunting.
