Is the BMW M5 reliable?
This super-saloon's reliablity record is a bit of a mixed bag. While it's often reported that the M5 is a disater waiting to happen, there are many owners who highlight that is isn't strictly the case.
If the car is regularly serviced and geniuine replacement parts from BMW are used to repair it, the M5 shouldn't cause any real cause for concern.
Notwithstanding the views of owners, the V10 engine is very highly strung and requires regular maintenance to keep your mind (and bank account) at ease.
The Vanos pump and throttle bodies are all known for going wrong, but if you spot any early warning signs, it's best to get these replaced as soon as possible to assuage any futher issues from occuring.
It's worth noting that BMW is an established brand with a large dealer and service network in the UK, so replacement parts should be readliy available.
Engine: The oil pump for Vanos (BMW’s variable valve timing system) is a common point of failure in the M5’s V10. Located in the oil pan and under significant pressure, it can wear quickly and fail catastrophically if left unchecked.
If you see an oil pressure warning light, or indeed a Vanos warning light, the Vanos unit itself or the pump could be on the way out. Budget £1500-£2000 for the replacement of each.
The engine’s 10 throttle bodies are controlled on two banks by as many throttle actuators. Owners have spent upwards of £1000 on replacing failed actuators, because if you need to replace one, the other must be replaced too. You should also have the throttle position sensors replaced, because both are directly linked.