Land Rovers – which were by far the most popular use of these engines in the United States – historically had undersized cooling systems, which poses a problem as overheating will kill the aluminum engine block (as described below). As such, it is imperative that the cooling system be kept in top shape, with regular coolant flushes occurring every two years at the latest. Immediately following any purchase of a used car with a Rover V8, the new owner should flush the cooling system using a cooling system cleaner, followed by several rounds of distilled water, to get all the old corrosion and crud out. Owners should also ensure that the clutch on the viscous fan is working as it should, and that the thermostat, radiator, and radiator hoses don’t have any leaks.

Land Rover temperature gauges are also historically awful. A vehicle can overheat and suffer catastrophic damage without even causing the needle on the gauge to move beyond normal. It is highly advisable to monitor coolant temperatures using OBD2 where possible (such as through a Bluetooth scanner connected to a smartphone) or an aftermarket digital gauge.

If you’re mechanically inclined, you may be tempted to purchase a Land Rover that has failed head gaskets and repair it yourself. This can be a great way to get a good vehicle for cheap. However, be very careful, as cracked engine blocks and slipped cylinder liners can often manifest very similar symptoms to failed head gaskets. Head gaskets are repairable, but cylinder liners require a resleeve (for which you should use top-hat liners if you go that route) and cracked blocks are not repairable at all.

• Carbureted engines (all vehicles produced prior to 1987) are legendarily unreliable; those with fuel injection are much better
• The factory black coolant reservoir is notorious for cracking and/or bursting. Land Rover released an updated part which solves this, and there are many aftermarket parts available. Preventative replacement is highly recommend.
• Susceptible to head gasket failure through simply through age

3.5L

• Land Rover Range Rover (Classic)
• Land Rover Series III

3.9L

• Land Rover Defender 90, 110
• Land Rover Discovery 1
• Land Rover Range Rover (Classic)

4.2L

• Land Rover Range Rover (Classic)

4.0L

• Land Rover Defender 90
• Land Rover Discovery 1
• Land Rover Range Rover (P38)

4.6L

• Land Rover Range Rover (P38)

With a redesigned intake to produce significantly more torque, and a new engine management system that provided smoother power delivery, the so-called “Bosch” generation of the Rover V8 should have been the grand finale of the engine. Instead, production issues turned them into curse words.

The root of the problem is simple – Rover had been producing the V8 for decades, and the production machinery was very worn out. Blocks had cylinder walls that were too thin, and the cylinder liners didn’t fit quite as well as they had in the older engines. Although the Rover V8 had its longstanding head gasket issues fixed in the “GEMS” generation of engines, the Bosch engines saw them start blowing again upon even mild overheating.

This time, though, head gasket failures were almost always accompanied by slipped liners or cracked engine blocks (which themselves often led to slipped liners for a holy trifecta of catastrophic engine damage). Although 1999 engines weren’t too bad, problems became worse with each succeeding year, peaking with the MY03-04 Discovery 2. Compounding the issues were the Discovery 2’s higher operating temperatures for emissions reasons.

Some also claim that the P38 Range Rover had stricter standards for the engine blocks, and that its rejected 4.6L engines ended up in the MY03-04 Discovery 2. This may explain why the P38 engines do not seem to have these issues while the D2 is infamous for it.

Some people in the Land Rover community claim that the 4.6L Rover V8 is most prone to slipped liners. This is not true, nor does it make sense, as the 4.6L block is identical to the 4.0L block – the 4.6L simply has a different crank, rods, and pistons. What is true is that the infamous MY03-04 engines just so happened to be 4.6L engines.

4.0L

• Land Rover Discovery 2 (L318)
• Land Rover Range Rover (P38)

4.6L

• Land Rover Discovery 2 (L318)
• Land Rover Range Rover (P38)