The M62 is a naturally aspirated V8 engine used by BMW in various 5-series, 7-series, and X-series from 1995-2005. The engine came in five size variants ranging from 3.5L to 4.8L, generating anywhere from 232hp to 370hp with the 4.8L features in the Alpina F5. In 1998 the engine received a technical update which included the addition of a single VANOS system for the intake camshaft, and electronic throttle control.
The S62, the M variant of the M62 was featured in the E39 M5, the infamous and super expensive Z8, among others. The M62 was also used in early-2000's Range Rover's and Morgan Aero's, along with a version of it being used in the Bentley Arnage.
We're going to dig into the reliability of the M62 by covering the most common problems the engine experiences, along with signs and symptoms for those with an M62 looking to troubleshoot issues. The order of the problems we mention is no specific order.
Head to the bottom of our post for a write-up on overall M62 reliability.
The Most Common BMW M62 Engine Problems
- Stretched cam chain / timing chain
- VANOS unit failure
- Leaking valve cover gasket
- M62 rough idling
- Excessive oil usage
- Radiator failure
- Bad engine mounts
1. M62 Timing Chain Guide Failure
The timing chain guides in the M62 are responsible for just that, making sure the timing chain is properly moving without any extra slack in the chain. The timing chain is made out of metal, and because metal on metal friction is a no-no, the chain guides were made out of plastic.
Over time, the timing chain guide wears down or breaks which creates slack in the chain and can cause the timing chain to jump or completely throw the engine timing out of whack. This happening could cause serious damage to the pistons and valves of the engine, so it is commonly replaced as preventative maintenance, given replacing it once it breaks is often too late.
The M62 develops timing chain guide problems in the 100k-200k mileage range. We typically recommend replacing the guides, tensioner, and chains at the 150k mark as preventative maintenance if they have never been replaced before.
Symptoms of a Bad M62 Timing Chain
- Check engine light indicating timing is off
- Noisy running and on start-up
- Whining noise from the cylinder head
Replacement Parts Kit: https://www.fcpeuro.com/products/clone-bmw-m62-timing-chain-guide-rail-kit-11311704945kt
DIY Replacement Guide: http://www.bimmerboard.com/forums/posts/876903
DIY Difficulty: very difficult. Replacing all of the components requires to you remove: the front bumper, accessory drive belt and pulleys and tensioners, the water pump, power steering pump, and alternator.
2. M62 Vanos Unit Failure
In 1998 the M62 received a technical upgrade which included the addition of a single-unit Vanos system. Vanos systems are responsible for what is called "variable valve timing", which electronically alters the valve lift timing for better performance, increased gas mileage, reduced emissions, etc. The single vanos unit in the M62 is responsible for altering intake camshaft timing. If you want to get into the nitty gritty of vanos, you can read our Vanos guide.
As is with any BMW with a vanos system, these are a frequent problem. They wear down over time and begin to stop functioning, resulting in various symptoms as described below. Fortunately, with the M62 a lot of the Vanos problems tend to be caused by the Vanos seals, rather than the actuator unit itself.
Symptoms of M62 Vanos Failure
- Vanos rattle noise on a cold start (usually first indicator)
- Vanos clanking noise when engine is warm or during driving
- Poor or rough idling
- Check engine light reading Vanos/timing is off
- Loss of power and low end torque along with poor performance
Replacement Options: either replace the full unit, or have it rebuilt. The DIY requires "moderate" mechanical skills, but will probably take a few days to complete and requires a number of specialty tools that are not cheap to buy. We recommend using someone such as DrVanos to do a full rebuild, but if you are trying to DIY it, you can checkout this guide here.
3. M62 Valve Cover Oil Leaks
It wouldn't be a BMW engine if oil leaks via the valve cover gasket wasn't on the list of common problems. Not dissimilar with the engines today, the M62 is also highly prone to valve cover leaks, mostly due to an old and deteriorated valve cover gasket.
M62 Valve Cover Gasket Leak Symptoms
- Oil building around the valve cover
- Burning oil smells from the engine bay
- Oil drips down the front or exhaust side of the engine
- M62 Valve Cover Gasket (Cylinder 1-4)
- M62 Valve Cover Gasket (Cylinder 5-8)
- Valve Cover Nut Seal - you need 22 of these
If you have a leaking valve cover, read this:
An oil leak at the valve cover can also result in oil leaking into the spark plug hole and into the cylinder head, fouling the ignition coils. If you had an oil leak and are also experiencing rough idling, slow start-ups, and other similar symptoms, you'll also want to replace your spark plugs and ignition coils.
4. M62 Rough Idling
I'm going to tap on this one briefly, because there are a number of issues that could cause poor idling, sluggish performance, or engine shaking on the M62. Here is a list of what you should check:
- Spark plugs and ignition coils (see links above)
- Vacuum leaks
- PCV valve
- Oil change
- Check engine mounts if its engine shaking and not idling issues
- VANOS system - see above symptoms
- MAF sensor
5. Excessive Oil Consumption
This common problem is less of a problem and more of a hassle. As these engines get older and into the upper-100k mileage range, they begin to consume oil at rates faster than normal.
If you are noticing this on your M62, also check your engine for oil leaks as this could be the culprit. If you have oil residue on your garace floor, or notice oil built up around the valve cover or dripping down the sides of the engine, then you probably have a valve cover gasket lead. Remove the valve cover and check your spark plugs to see if they are wet with oil, if so replace them.
Always keep an extra few quarts of LiquiMoly oil in your trunk in case you get a low oil light while out travelling.
6. M62 Radiator Failure / Cooling Issues
The M62 came with a great cooling system new, but unfortunately wear and tear from time eventually catch up to it. Radiator failure is a common problem, but people also have issues with the expansion tank which creates a coolant leak, heater hose failures, water pump failure, and leaks from a cracked radiator itself.
Symptoms of M62 Failing Cooling System or Radiator
- Cracks in the radiator stem
- Engine overheating frequently (biggest tell tale sign)
- Coolant leaks around the radiator or expansion tank
- Overheating at idle (this is probably the auxiliary fan)
7. Bad Engine Mounts
This is common for any old vehicle with significant mileage on it, not just the M62 and not just BMW's. Engines shake, to a degree, naturally, but you also experience all sorts of bumps and shakes from the road too. If engines were simply mounted to the metal frame of the car, a ton of problems would be caused and the car would shake like crazy. Engine mounts act as a buffer between the metal frame and the engine itself, and are usually made out of rubber or polyurethane to absorb some of the shaking which makes the car safer and more driveable.
As engines wear, these rubber engine mounts can tear, break, or just plain deteriorate. Fortunately, bad engine mounts are usually very easy to diagnose.
M62 Bad Engine Mount Symptoms
- Noises coming from the engine bay (clunking, banging, vibration noises, etc.)
- Excessive vibration that can be felt inside the car
- Rattling of interior trim pieces
- Engine shaking (open your hood with the engine on and see if it is shaking badly)
Replacement parts: the part will depend on whether you have a 3.5L, 4.4L, 4.6L, and so on. Head over to https://bmwpartsfactory.com to get motor mounts for your specific engine.
BMW M62 Reliability
The BMW M60 V8 engine was the predecessor to the M62. The M60 was used in the E32, E34, and E38 5-series and 7-series. This engine was considered to be one of the BMW greats, and was bulletproof in terms of reliability. However, in an attempt to keep up with the power of the other German vehicles of the era, BMW released the M62. The M62 was bigger, and produced more horsepower, which in turn decreased overall reliability.
As a TL;DR, the M62 is overall a somewhat reliable engine. But, if it hasn't been properly maintained, it can be a money pit. As with any old BMW, these cars become very expensive unless you are a serious DIY'er. The M62TU engines tend to be the worst out of the variants with respect to reliability. If you are looking to buy one in today's time, just understand there is a lot of preventative maintenance to be done, and if it is >150k in mileage, you will probably run into issues with: vanos, the whole cooling system, timing chain and guides, alternators, etc.