too much torque on the N20 and the block could crack

[hyper1]

Some interesting information was posted in the N20 section of the *********** BMW forums regarding the durability of the N20 motor. Now, the motor is becoming very popular and is winning multiple awards and rightfully so as it is currently the best factory 2.0 liter turbo four cylinder in production. The keyword there being factory as apparently it is not going to be a stout aftermarket tuning platform at least not yet. Take the information you are about to read as unconfirmed but from an interesting source.

There are companies that stress test engines for OEM's. One of these companies has been testing the N20 apparently. The advice given is not to go beyond Stage 2 on the N20 which means a slightly more aggressive tune on the factory turbocharger. Why? The N20 head apparently cracks at around 331 pound-feet of torque. That is not exactly a whole lot of torque in the turbo tuning game especially considering the motor puts out an underrated 258 pound-feet from the factory.

Apparently the engine is just running very hot and multiple heat cycles are creating problems. BMW behind the scenes is supposedly trying to correct the issue. For whatever reason BMW seems to have a reputation for problems with new motors. S54 bearings, S65 bearings, and the next BMW new motor issue looks to be the N20 head cracking.

The story is that one of the lead designers and engineers for the N20 was flown out to the USA to inspect the findings for himself. It is doubtful BMW would do that unless there was something of substance to this. This same company also apparently tested other BMW motors including turbo motors such as the N54 and N55 when they were new and they did not run into these head issues.

So what is going to happen? Well, right now it is not recommended for N20 owners to push their motors too far which they can't anyway as there are not aftermarket turbo options out just yet. BMW will likely resolve the problem with a new head which will mean for those with the N20 there will either be a recall or there will be a BMW part number option to get the new head. We will have to wait and see what happens but N20 owners should be aware of the potential issue especially if intending to tune as BMW is unlikely to say anything until they have to.

[Gunzaro]

Actually the Mercedes Benz AMG A45 2.0 litre 4cyl turbo is 'superior' to the BMW offering and is currently the most powerful production 4cyl turbo engine.

[wmandra]

the original post is almost 1 year old.... to date there are no known instances of cylinder heads cracking in the field. having said that, there have been cases of blown connecting rods and BMW has gone through 4 different piston designs on the N20.

Its a moot-point for the time being as there isn't any tune/upgrades available for the N20 that will deliver the kind of power levels indicated.

[hyper1]

thanks for all the info's
I did not know the topic was over a year old.
I just saw it about a week ago.

[nicknaz]

Originally Posted by wmandra

the original post is almost 1 year old.... to date there are no known instances of cylinder heads cracking in the field. having said that, there have been cases of blown connecting rods and BMW has gone through 4 different piston designs on the N20.

Its a moot-point for the time being as there isn't any tune/upgrades available for the N20 that will deliver the kind of power levels indicated.

That's actually not a moot-point..

That info on the engine running hot and multiple heat cycles causing cracks, as well as connecting rod failures should be a key consideration for someone looking for a sporty car to modify and use for track days

Maybe buying the F80 with brand new S55 motor isn't a great idea yet... (but then again, what new motor design is a risk free... great example are the water cooled porsche engines, and most recently the 991 GT3 fire issue)

[wmandra]

Originally Posted by nicknaz

That's actually not a moot-point..

That info on the engine running hot and multiple heat cycles causing cracks, as well as connecting rod failures should be a key consideration for someone looking for a sporty car to modify and use for track days

Maybe buying the F80 with brand new S55 motor isn't a great idea yet... (but then again, what new motor design is a risk free... great example are the water cooled porsche engines, and most recently the 991 GT3 fire issue)

what does the S55 motor have to do with the N20?

please find and read the original thread on the other forum. The original claim made was that the head cracked after about 100k miles with 331lbft of torque.

as i said before its a moot point right now as there is no aftermarket options available for the N20 that will bring it to these power levels (still don't even have control of the electronic wastegate yet). In addition, I haven't seen or heard of a single instance of an N20 head cracking.

The possible piston issue is cause for some concern if/when larger turbo upgrades start to become available. The stock turbo is good for about 24-25psi of boost, though 23psi seems to be where the engine is making best power with the stock turbo. The N20 is now on its 4th piston revision (one variant with different oil spray nozzles). The original piston was used up to Feb 2012, second until April 2013, third until August 2013 and the current variant. This many changes in that short of a time period says BMW had been working through an issue - especially the second variant only being in production for 2 months.

The N20 in the Z4 is great on the track with the stage2 JB4. I had mine out for about half of last season and will be out about 25 days this season. Like anything else though you have to be prepared for additional maintenance (which you should be doing anyway if you track a car).

[nicknaz]

Originally Posted by wmandra

what does the S55 motor have to do with the N20?

New motor

I was commenting on the OP's original statement "For whatever reason BMW seems to have a reputation for problems with new motors. S54 bearings, S65 bearings, and the next BMW new motor issue looks to be the N20 head cracking."

If you are running stage 2 aren't you close to this power level already?

For what it's worth I took 5 minutes to browse the forums and found a few examples of 300+ tq at that wheels and anecdotes of engine failure. Seemed like the failures were from hydrolock from running a meth kit though, not from more boost/power

EDIT: wow.. our forum blocks the URL name of competitor forum!!!

[wmandra]

Originally Posted by nicknaz

New motor

I was commenting on the OP's original statement "For whatever reason BMW seems to have a reputation for problems with new motors. S54 bearings, S65 bearings, and the next BMW new motor issue looks to be the N20 head cracking."

If you are running stage 2 aren't you close to this power level already?

For what it's worth I took 5 minutes to browse the forums and found a few examples of 300+ tq at that wheels and anecdotes of engine failure. Seemed like the failures were from hydrolock from running a meth kit though, not from more boost/power

EDIT: wow.. our forum blocks the URL name of competitor forum!!!

ahhh.. I see your point on the S55....

Stage 2 max torque is around 318lbft, close - but not quite at the 331lbft level that the original article stated.

BTW, I was surprised by the URL block on the other forum also.

[nicknaz]

Whats your oil temperature situation on your N20? I did not see cooling modifications in your other thread

In the stock N54 on my car I hit limp mode and power reduction really easily, especially when there are lots of chances for full throttle, like "big willow"

I am speculating completely here, but can't help but wonder if better cooling and venting the engine bay will help out with this alleged head cracking issue. Or if the cracked part of the head was close to the downpipe

[wmandra]

oil temps have been rock solid on mine, even when pushing hard on the track. 2 days at watkins glen and temps never went above 250F. I've actually considered installing the auxiliary radiator that comes on the N20 in the X3, but held off. I may log water temps when I go to Limerock next month and see what they look like. I think there may be something to what you were saying about better cooling in the engine bay, the Z4 bay is significantly larger than the 3-series.

[Hujan]

Originally Posted by wmandra

oil temps have been rock solid on mine, even when pushing hard on the track. 2 days at watkins glen and temps never went above 250F. I've actually considered installing the auxiliary radiator that comes on the N20 in the X3, but held off. I may log water temps when I go to Limerock next month and see what they look like. I think there may be something to what you were saying about better cooling in the engine bay, the Z4 bay is significantly larger than the 3-series.

It has better air flow from the kidneys, too. In the oil cooler thread we had going before, someone (was it you, Nick?) mentioned dropping in the radiator fan from the 335is or 1M, which should be PnP for our cars (at least on the N54). That would help on an N54 car.

Nick, I bet you would see oil temps drop a lot if you threw some catless downpipes on there. I know you're reluctant to do invasive bolt-ons due to warranty issues and understand your concern, but I'm just mentioning this as a theoretical matter. I saw oil temps drop on my Mini with the N18 when I put a downpipe on there.

[wmandra]

the N20 Z4 uses the same 600W fan as the N54, so I would think the 850W fan from the 335is would a decent upgrade. Don't know about the N54, but on the N20 the JB4 has a "Max Cooling" mode which essentially runs the water pump and fan at full power all the time.

[Hujan]

Originally Posted by wmandra

the N20 Z4 uses the same 600W fan as the N54, so I would think the 850W fan from the 335is would a decent upgrade. Don't know about the N54, but on the N20 the JB4 has a "Max Cooling" mode which essentially runs the water pump and fan at full power all the time.

That's good news. I've tried to source one on eBay before, but no luck. Would love to pick one up if it wasn't too expensive.

[nicknaz]

Originally Posted by Hujan

It has better air flow from the kidneys, too. In the oil cooler thread we had going before, someone (was it you, Nick?) mentioned dropping in the radiator fan from the 335is or 1M, which should be PnP for our cars (at least on the N54). That would help on an N54 car.

Nick, I bet you would see oil temps drop a lot if you threw some catless downpipes on there. I know you're reluctant to do invasive bolt-ons due to warranty issues and understand your concern, but I'm just mentioning this as a theoretical matter. I saw oil temps drop on my Mini with the N18 when I put a downpipe on there.

hey! thanks for the tip on the DPs. I did not realize the DPs would help the temps.

Since we last spoke, it has taken huge willpower not to break down completely and take the car to full bolt ons + RB turbo swap... My older brother pick up his E63 wagon and that power level has me drooling

Yes, I did speculate the 335is/1M 850W cooling fan was would be plug and pay. Others have done the swap in E90 world but I haven't seen it for our E89

wmandra, yes the JB4 for N54 has that max cool mode too. do you know if that functionality is available for the Cobb Accessport? It seems like the N20 cooling system does a better job of managing engine temperatures. I hammered on a F30 328 xdrive for 30 minute sessions at a short track (toronto motorsports park) and didn't get any oil temp increase either.

[wmandra]

nick, glad to see your observations on the F30 328 mirrors mine. I'm not sure if the max cool feature is available via cobb, possibly using the BMS backend flash.

If the 850W cooling fan were cheaper I'd probably give it a shot.

[nicknaz]

Originally Posted by wmandra

If the 850W cooling fan were cheaper I'd probably give it a shot.

$400
http://www.e90post.com/forums/showthread.php?t=800089

It has been on sale on and off since 2011 with no takers.

[Hujan]

Originally Posted by nicknaz

hey! thanks for the tip on the DPs. I did not realize the DPs would help the temps.

Since we last spoke, it has taken huge willpower not to break down completely and take the car to full bolt ons + RB turbo swap... My older brother pick up his E63 wagon and that power level has me drooling

You'd love it, my friend. Downpipes might be a bigger concern to your dealer, but at the same time it's the type of thing they would never find unless you had a catastrophic engine failure (in which case, you could remove the DPs before taking the car in for a new engine).

An FMIC would be a bit easier to detect, but is also harmless. I would love to see BMW NA try to pin any engine trouble on a FMIC.

As I said, I've had warranty work (not engine, mind you) done on the M3 with a full exhaust at Encinitas and they didn't bat an eye. The crazy thing is that unlike the N54 where the downpipes are buried in the engine bay, all the cats on the M3 are in plain sight underneath the car. You can tell with one look that I've removed the primary cats (effectively the cats in our downpipes).

[hyper1]

so i can have my last post on the Z4 I28.
I traded the car for a truck. However 3 monts before the trade i had a yellow transmission line. they change something from inside the car that was attach to the shiffter. after that for the next 3 months every week i had a yellow engine light. The engine would shake until the engine was turn off.
That was driving on sport mode pushing hard. They change one injector.
Then the Z4 was gone. The new owners same thing with the car shaking.
then they replace all the injectors. and a month latter again the engine gasket add to be replace for a new one.

Maybe it was just the luck of the draw.