As requested by the club, I have listed a few known faults with the MG & Rover range of vehicles. This list is by no means extensive but are a few problem areas that we have encountered over the years at H.A.S.
K series engine – Head Gasket Failure & Rectification
The K series engine is generally a very reliable power plant, but is prone to the Head Gasket failing at virtually any time.
Although it can fail at any time or at any mileage, it doesn’t actually follow a specific timescale. We have replaced them as early on as 20000 miles and as late as 90000 miles. Although MG Rover issued a TSB stating that after 1999 the fault was rectified at the factory with improved and modified components, we have seen them in our workshop as late as manufacture in 2003 with the fault still existing.
Another factor that this engine always displays is that when the gasket fails it is almost immediate with very little warning of impending failure. The coolant disappears closely followed by the engine instantly running hotter and the coolant mixing with the engine oil.
When the coolant starts to disappear it generally goes past the gasket and into the oil galleries. This then mixes (emulsifies) with the oil and raises the engine oil level leaving a coffee coloured mixture visible on the dipstick and the underside of the filler cap. It is not unknown for the coolant to avoid mixing with the oil and leaking outside of the cylinder head instead. If the early symptoms are not identified immediately, then the problem can escalate into more serious engine damage. It is essential that the engine is not run once the coolant has disappeared. It is not practically possible to refill the cooling system and run the engine without bleeding out the remaining air in the sealed cooling system. Once the coolant is lost then this process is ongoing, loss of coolant, engine overheating and boiling off leaving air to block the flow of coolant. If the engine is run until it overheats, then engine component damage is likely, not to mention that the oil is not effective when it is thinned down and emulsified. It is better to have the vehicle collected on a recovery lorry rather than chance driving it and destroying the engine.
MGZT / Rover 75 – Fuel Pump Failure
There is a common failure on the ZT / 75 range of vehicles where the fuel pump fails to deliver fuel usually when the car is driven onto a driveway and then failing to restart later on. The fuel tank on these vehicles is designed as a saddle tank (raised in the middle to accommodate the exhaust system (or propshaft on the V8 version). This design feature means that a separate pump and pickup are used to draw fuel from both sides of the tank. The problem is that the fuel pickup assembly on the left hand side can sometimes disassemble and draw air instead of fuel. The rectification is fairly straightforward although rather risky as the fuel tank internals have to be stripped, exposing the fuel and vapours.
The parts that need to be replaced are relatively cheap but the job itself is very labour intensive as the top half of the engine (inlet manifolds, etc) have to be removed to gain access to the failed parts. Not a job to attempt on a Sunday morning on the driveway!
MGZT / Rover 75 – Diesel Fuel Burning Heater (FBH) fault
The Fuel Burning Heater (FBH) on the diesel version of the ZT / 75 vehicle range is definitely a ‘must have option’ as it allows the engine and interior to heat up very quickly on a cold day. However, when it goes wrong it can be very expensive to rectify. The problem is that is remains switched on even when the engine is switched off. The fuel is drawn directly from the fuel tank and continues to ‘burn’ resulting in the coolant being evaporated and leaking air-locks in the cooling system. The heater assembly also generates a great deal of heat, which if left unchecked could result in the vehicle catching fire. One to watch out for, but failures of this type are very rare.