N62 Engines

[tdgard]

I had an E34 with the Nikasil block. Never had a problem, but you knew it was lurking. Pretty stressful actually.

[TowX]

The same debate about boring, or even honing, Nikasil or Alusil cylinders has been around for decades in the Porsche community. Mahle made the Nikasil barrels for the 911 engines and KS made the Alusil. There are those who say you can't do anything to the bores on the Nikasil barrels, but there are a couple of companies who have introduced a process to recoat the bores. Alusil is similar but there are more people who say that it can at least be honed.

I know that in an old 911 engine with Alusil barrels that I had about 20 years ago, I honed the bores and it took forever to get the new rings to seat. I finally gave up and bought a used set of matched Nikasil pistons and barrels with a larger bore for increased displacement.

My current 911 engine is at the machinist to have the crank balanced and polished, and to have bigger valves installed. He's also got my Nikasil pistons and barrels. He said that I still have a good crosshatch on the walls which is good because in his 30+ years of building street and race 911 engines he's never had good luck machining a Nikasil bore- other than on pure race engines that were torn down after every race.

[killcrap]

The majority of N62 cylinder head failures on x5s usually only occur on 2004-2005 models. Intermediate levers are not included in this. The main issue with these heads is oil consumption. Worn out valve guide are the cause. These can be machined and corrected.

The short block would consist of only the block with pistons.

BMW's recommendation to correct the uneven cylinder filling at cold temperatures is to replace the intermedate levers, shafts, lifters, and rockers. This has always solve the concern. If the failure occurs again, BMW warranties the repair for 2 years.

[fmugur]

It's been a year and a half, do we know more about this n62 engine issues?
I am about to get a 4.8is with 235000 km. Reading more about the n62 issues I am worried that buying it might be a bad idea. When do these engine start to fail?

[fmugur]

It is from another forum but is this true?
..."but "properly maintained" on these engines means an engine rebuild at some point to clean the heads, secondary air passages, replacing the valve stem seals. Then of course the coolant transfer pipe, all the gaskets. "

[fmugur]

On another thread killcrap states:
"all n62b44 and n62b48 variations have this problem, the production dates dont mean anything. it is a design flaw. rough running. i have worked on 2 or 3 cars where it has been through 3 sets of levers and shafts. early e65 vehicles had rough running at engine operating temperature in warm climates also, e53 vehicles have the majority of the problems in cold weather."

and

"they wore out every 30k miles. and each time it has been goodwill repair, that car has also been through 2 intake manifold, 1st time is was siezed and 2 time it was sloppy."

Is this still really the case now? Did BMW come with a better solution?
Is this what you guys are doing every 30k miles?

[Skyline]

To me, an engine should last 200k miles without having to come apart for multi-thousand dollar repairs. And there's no reason a transmission should not last that long either; with many car models, transmission failure prior to 200k is unheard of. With others, it's the norm.

I can live with an occasional gasket failure, but only random events, not if it's every one, (the failure rate of the valve cover gaskets on the BMW V8s is ridiculous).

I can live with water pump failures. Timing belt changes are OK. Valve adjustments are OK on performance engines.

But everything else is an engineering failure that should NOT happen. We always hear that these boards only report failures and not the good.

So lets hear it....Who has a high mileage N62 that has NOT had to come apart???? Or NOT lost a transmission?

[TiAgX5]

Originally Posted by Skyline

To me, an engine should last 200k miles without having to come apart for multi-thousand dollar repairs. And there's no reason a transmission should not last that long either; with many car models, transmission failure prior to 200k is unheard of. With others, it's the norm.

I can live with an occasional gasket failure, but only random events, not if it's every one, (the failure rate of the valve cover gaskets on the BMW V8s is ridiculous).

I can live with water pump failures. Timing belt changes are OK. Valve adjustments are OK on performance engines.

But everything else is an engineering failure that should NOT happen. We always hear that these boards only report failures and not the good.

So lets hear it....Who has a high mileage N62 that has NOT had to come apart???? Or NOT lost a transmission?

Good idea, N62 owners need to reply.

The N62 issues caused me to buy a late production date '03 4.4 X5. I avoided the N62 Xs like the plague, would not drive around the corner to look at an N62 yet willing to drive and view all M62 Sport Pkg Xs in a 200 mile radius.

[SlickGT1]

Subscribed. I'm at 81k miles now. Still running fine.

[Nick P]

M60/M62 is the 2nd best BMW engine ever, after M50 IMO