The BMW N62 engine was the successor to the BMW M62 V8. It was in production for nearly a decade, from 2001 to 2010, and powered multiple models, including the E60/E61 5-Series and the E65/E66 7-Series. Iterations of this engine also made their way onto several Alpina models. Despite being an impressive engine on paper and out in the real world, the N62 is often looked down upon by enthusiasts because it was somewhat unreliable and usually has some issues.
That said, there’s no denying that this is still a great engine to drive. In 2002, the N62 won the ‘Best New Engine’ and ‘International Engine of the Year’ awards, which tells a story of its own. If you can get your hands on one that’s in relatively good condition, it can be quite an enjoyable experience.
Technology Behind BMW N62
The BMW N62 engine, like its predecessor, is a naturally aspirated V8 engine. It was BMW’s first V8 to feature the manufacturer’s Valvetronic (variable valve lift) system and also the world’s first engine to have a continuously variable-length intake manifold.
Features like the aluminum engine block and cylinder head forged connecting rods and double-VANOS (variable valve timing on intake and exhaust camshafts) were carried over from the M62.
Available Versions
The N62, over its lifespan, was available in four engine sizes — 3.6 liter, 4.0 liter, 4.4 liter, and 4.8 liter — depending on its application. Alpina also used a version of the 4.4-liter engine. Here’s a quick look at what each of them had to offer. The 4.4 liter displacement was shown to be popular with the M62, and its performance version – the BMW S62 engine. BMW kept this option with the N62, as expected.
3.6 liter
The 3.6-liter iteration of the BMW N62 engine was dubbed the N62B36. This version displaced 3,600 cc and produced peak output figures of 268 hp at 6,200 rpm and 266 lb-ft of torque at 3,700 rpm.
4.0 liter
Dubbed the N62B40, the second iteration of the N62 displaced 4,000 cc and produced 302 hp at 6,300 rpm and 288 lb-ft of torque at 3,500 rpm.
4.4 liter
The N62B44 displaced 4,398cc with output figures of 329hp at 6,100rpm and 330lb-ft of torque at 3,600rpm. This engine also powered the E53 X5, on which it made a slightly lower 315hp at 6,100rpm and 325lb-ft of torque at 3,700rpm.
4.8 liter
The largest iteration of the N62, the N62B48, displaced a substantial 4,799cc and also produced the most power and torque — ranging from 350 hp to 362 hp and 350 lb-ft to 369 lb-ft of torque, respectively, depending on which car it was used on.
Alpina H1
The Alpina H1, based on the N62B44, powered multiple cars in the Alpina range. Changes to the engine included a new engine block, a forged crankshaft, and high-strength pistons from Mahle, along with the addition of a centrifugal supercharger. Peak output figures on the H1 ranged from 493hp to 523hp and 516lb-ft to 535lb-ft of torque.
What Cars Feature the BMW N62 Engines?
Here are all the cars that the BMW N62 powered:
N62B36
The N62B36 powered the BMW E65/E66 735i/735Li cars from 2001 to 2005.
N62B40
BMW employed this engine in the E65/E66 740i/740Li sedans from 2005 to 2008 and the E60/E61 540i sedan and touring versions from 2005 through 2010.
N62B44
The N62B44 was at the heart of the BMW E65/E66 745i/745Li sedans from 2001 to 2005 and the E60/E61 545i between 2003 and 2005. This engine also powered the E53 X5 4.4i from 2004 to 2006.
From 2003 to 2007, it was also on the second generation of the BMW 6-Series — the E63/E64 645Ci. Lastly, from 2005 to 2007, the Morgan Motor Company also used it on the Morgan Aero 8 Series 2 and Series 3.
N62B48
The N62B48 was the most popular of the N62 engines. The 350hp version of the engine was used on the 2007-2010 BMW E70 X5 4.8i SAV; the 355hp iteration powered the 2004-2006 E53 X5 4.8iS; and the 362hp version was employed on the 2005-2010 E60/E61 550i, 2005–2010 E63/E64 650i, and the 2005-2008 E65/E66 750i/750Li. This last engine version also powered multiple models in the Morgan range.
Common BMW N62 Problems
As we mentioned earlier, the N62 suffered from a number of issues. If you’re in the market for one, here’s what you should be keeping an eye out for:
Coolant Transfer Pipe Leak
The coolant pipe leak is one of the N62’s notorious problems. It’s usually caused by the front seal on the coolant transfer pipe. This seal is located under the intake valley pan, which is quite hard to access; you need to dismantle the timing cover, timing chain, intake manifold, and cylinder heads to access it. Consequently, this is a labor-intensive job that can take up to a couple of days from start to finish.
If your car is leaking coolant, the low coolant light on the dash should light up — this will also result in your engine running hotter than usual. The leaking coolant drips out of the weep hole, which is located in the timing chain cover; this is a sure-shot way of diagnosing if there’s a pipe leak.
The Valve Stem Seals
The N62 is a V8 engine with a DOHC layout, resulting in a total of 32 valves. Each valve has a stem seal that prevents oil in the cylinder head from leaking into the combustion chamber. These valves also regulate the lubrication of the intake and exhaust valves. The seals on the N62 are not made of a durable material and can degrade sooner than usual.
If they crack, they will allow oil to leak into the combustion chamber. This can result in increased oil consumption, smoke from the exhaust during a cold start, and white-blueish colored smoke during regular running.
Valve Cover Gasket Oil Leaks
A valve cover gasket oil leak is an issue that plagues multiple BMW engines, and not just the N62. In most cases, it happens over time, after the heat from the engine wears the gaskets down and causes them to crack. Maintenance checks in regular intervals can help avoid this. If the valve stem seals have been replaced, the gasket has likely been swapped out for a new one, as well.
The smell of burning oil, an oil leak, or smoke from the valve cover region could likely mean that the gasket is due for a change.
Oil Pump Check Valve
Owners of BMW N62 engines, especially the 4.4-liter version, have reported a serious problem while replacing the oil pump. If not done carefully, parts of the oil pump check valve will break off and get into the filter housing. The check valve prevents oil from flowing back into the oil pump, and the most optimal way to get it fixed is to replace the entire system.
Resolving this can be really expensive — essentially, the entire front end of the car will have to be dismantled — but it’s still a better option than replacing the engine.
Alternator Bracket Oil Leak
The alternator bracket/gasket is the part that holds the alternator in place in the engine. If it comes loose or cracks, it can result in an oil leak.
Like any other gasket, the most common cause of failure is regular wear and tear. It’s best to check it in regular intervals or every time you’re working on the engine to see if it’s showing signs of wear and impending failure.
Valvetronic Motor Oil Leak
Overall, the Valvetronic system is quite reliable. However, it comprises a Hydraulic Valve Adjuster (HVA) that can sometimes throw up problems. A faulty HVA can result in a ticking noise from the engine, and if not resolved soon, could cause severe damage to the camshaft and even the valve shaft.
Apart from the ticking noise, you may also find that the engine idles inconsistently or misfires. A technician will have to adjust the hydraulic valves to resolve this issue.
Can a BMW N62 Engine Be Reliable?
Just like any other engine out there, the N62 can be made reliable if it’s maintained properly using quality parts. Here at Bimmers.com, we carry a whole array of genuine, OEM and aftermarket parts that will help you get the most out of your BMW N62 motor and enjoy every moment you spend with it.
Head over to our online store, select your car’s model and year using our navigation tool, and you’ll get a complete list of parts that match your query.
