N62 Engines
 

Last weekend, I met a friend that I didn't see for a couple of years. He's a BMW tech. I told him I was selling
my E46 to get a N62 X5 (4.8is or 4.4i).
His reaction was like I anticipated. Requires lots of maintenance, etc, etc.
I told him I was ready to deal with all those problems, even transmission problems.

But, when he started talking about N62 engines getting replaced at a very high rate because of cylinders
getting oval toward the top, I became speechless.
BMW doesn't sell short blocks, only long blocks, at 20K retail... ouch!
He says that the M62 was not doing that and is more reliable, true??

I then asked him if those 'N' engines could be rebuilted, and he said no, well, BMW doesn't do it.
I read on this forum that someone had success inseting sleeves in one of those engines. Could that person tell
me if it was a custom job, of those sleeves/pistons are available through engine rebuilding shops?

If some BMW techs on this board or N62 owners read this, could you tell me if you have seen this wear pattern
on the N62, or they are isolated cases.


Lastly;
There is something he told me that could help N62 owners with idle problems. He told me that replacing the
intermediate levers, and shaft doesn't always solve the problem. They found that the valves were getting a lot
of deposit on them and were either sticking, or not closing properly. He says he now removes both heads,
disassemble completly, and clean / gring all the valves by hand + change the levers + shafts. It seems to solve
the problem.
I really wanted a N62 X5, but now I'm not sure if a M62 will be more bulletproof.

There aren't posts on here about oval cylinder bores, as I recall. What doesn't fit for me is that both the M62 and N62 use the same technology for the cylinder bores (aluminum blocks with Alusil). Not sure why one would be much different than the other.

Deposits on valves are often related to poor quality fuel, with insufficient additives to clean the deposits away.

There are lots of things that can break on an X5, and some maintenance and repairs will be required, but engine overhauls are not one of the things I would be worrying about.

I've been a dealer tech for about 6 1/2 years and have yet to see any N62 engines come through with cylinder damage as described.... maybe those were severely overheated or something?

The only issue i have had with my N62 is intermediate levers. Which honestly was no big deal in my opinion. But otherwise shes still running strong at 91k miles.

my transmission on the other hand.. luckily replaced under CPO warranty 8 months ago.

Thanks for the feedbacks, it is good to hear that it is not a common problem.

I took a look on realoem, and to my surprise, I saw that oversized pistons were available for the N62. I always tought that an Alusil block couldn't be re-bored because it removes the coating on the cylinder walls. So why those pistons exist?

I'm still interrested to hear from the person who installed linings in a M/N62 block, please chime in.

I know M5james has a sleeves M62 in an E38 7 series... that's probably who you're thinking of.

I worked at a local BMW dealer during college many years ago and recall seeing a high number of 740 and 540 cars come through requiring new engine blocks because of the the block/liner material. Don't recall the specifics but I think it had to do with a low (or maybe high) silicon content in the casting/liner. Something about the cylinder bores wore out due to the material used. Owners got a new engine block from BMW at no cost. The X5 wasn't out yet so I never saw those vehicles while working there.

I have data somewhere . I will post it here sometime ( may take a while to find time to look ) .
M60 V8 engines had NIKASIL cylinder walls which were destroyed by high sulphur content in fuel . EDIT - some engines still have Nikasil , some have Alusil depending on which country the vehicle was originally sent to .
maybe some early M62 `s were affected , maybe not .
some engines have ALUSIL blocks , no coating on the cylinders as the alloy is hard enough .
the data has all the info , when I can locate it .

EDIT - found it in minutes . had to make a PDF because file would not load otherwise .
had to delete page 24 because PDF was too large . no big deal , it was only starter motor info .

^^ that was the problem. I remember a good number of 740 and 540 equipped cars came through the shop and the only BMW tech made a killing off the work. He had it down to a science after the second or third engine replacement.

If I recall they only sent a short block. Don't remember if it came with new pistons and such.

But you could definitely tell which engines had the problem and which didn't. They tended to have less power and knocking noises.

Yeah, the original M60 with nikasil... that problem had just cleared up when I started, so I didn't get to do any of those.

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

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.

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.

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?

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. "

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?

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.

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

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

N62, 104000 km, still running fine on Mobil1 0W40.

The M60? :stickpoke There's a lot of 1993-95 e31/e32/e34/e38 M60(B30) & M60(B40) owners here in the USA that had the Nikasil issues where they had to get replacement engines or warranties extended to 100K miles/6 years from BMW that may disagree with how great the M60 engine was. :)

And many BMW owners that had models with the venerable M30 engine may take umbrage with your statement. BMW squeezed almost 30 years of life outta the M30 engine...whereas the engines since then have had a much shorter life-span....there's been some great modern BMW engines since...but none the long-lived life of the M30. :D

Just a thought...not an argument. :)

BTW...N62B44 engine with 109k ...but I'm only 3 weeks into ownership...so I have my fingers crossed for a good run...I hope time is on my side. :popcorn:

The only problem I've heard and fixed on mine already is the chain guides after 200000 km.

Rumor has it a high mileage X5 reporting no issues will soon have issues.


I will not be disclosing my mileage or issues, then. :D

IMO, the list of best BMW engines starts with the six cylinders, goes to the four cylinders, follows with the twelve cylinders, and ends with the eight cylinder models. If we have to include the ten cylinder models I would put them with the eight cylinder models. The exception would be the M20B27 eta engine, a six cylinder masquerading as a four. All IMO.

M60 is capable for 650 HP, with no problems so far, a friend of mine built a 0,9 bar supercharged M60 with 4.6 l displacement in E36 - bored and stroked, the only forged non-OEM parts he used were forged pistons for 8,5:1 compression rate, even the rod bearings are stock. The car has done 6000 km so far, mostly on race tracks and there were no single issue with the engine, but in this 6000 km he replaced 1 gearbox, 2 diffs, 2 sets of stock driveshafts and 1 propshaft, now he got a heavy duty diff, custom made drive shafts and very stable propshaft installed, also the diff mounting and the floor were reinforced. The S6S Gearbox is also still stock, so he has to shift carefully to save the synchromeshs, but the main shaft bearing seem to be fine even with this kind of power and torque (790 Nm with agressive maping)

He's currently building 2 other supercharged M60 - one of them is ready to be installed in to E36 cabrio, and the other one goes in to 99 Z3 Coupe.

So what Nikasil issues you're talking about? Not to mention, even not the all M60 engines had nikasil coating of cylinder walls. I also know a guy in Austria, who built a ITB 4,5l M60, which revvs up to 7,7 rpm, using full forged internals, this engine showed 440-450 on engine dyno. He got it officially installed and registered in Austria and this engine seem to be more reliable, than S62 with less power and more displacement.

M60 (and also M50) heads have e very good flow rates, which are for sure not comparable with flow rates of SOHC heads, of the engines, which could be more reliable in BMW's history.

M50 as a 2,5 l version with iron cast block is capable of 600 hp on stock internals (exept again for pistons) and such a set up will be reliable for at least km 40-50k.

So that were my reasons to call these 2 engines the best BMW engines ever IMO.

n62 engine problem
 

dont buy x5 with enginewhat your friend say is all true
i have the say problem end resolve it you must pay lot of money

WHat oval? the cylynders ARE ovan in shape when cold, they are supposed to be like that

2005 4.4i w/89k miles (approaching 90k!). Transmission replaced under CPO. Engine fine.