[DonDre]

If you'd like additional info and media, I worked with FCP Euro to create this article linked below.


N54 Ownership Guide



This is a guide i wrote up. Hope this can help potential buyer and owners that have questions or issues . I will be be adding additonal info as days go on

Buyer/Owners Guide to the E9X 335i

Congratulations, you have purchashed or looking at purchasing one of the best Luxury Sport Coupe/Sedans you can buy for under $20k. This car just does everything great for what it is. It’s very quick, handles well, easy to modify for more power, and if you drive conservatively it can get 30mpg highway. It is also very practical. The E92 Coupe is the most Roomy coupe compared to other coupe in this used car price range ( Infiniti G37, Mercedes-Benz CLK550, Audi S5, Mustang 5.0, and Hyundai Genesis Coupe), and it has a pretty big trunk. However nothing is perfect, one of the downfalls of the 335i is it track record with reliability. If you done your research on this chassis and know it’s potential problems, you are on the right track. The purpose of this guide is to help potential buyers and current owners be informed on this car, and how to avoid getting into a nightmare situation with your wallet. I will break this guide will have information that I personally experienced, and information from things I’ve learned from my research. There are 2 engines that came in the 335i, the N54 and N55. Because I personally wanted and currently own the N54 powered 335i, I haven’t done much research on the N55 yet. The info about the N54 is from over 9 months of research prior to buying and things I’ve learned during ownership

The N54 engine and it Potential Issues

The N54 engine doesn’t need much of an explanation because this engine is the reason why most modding enthusiast go for this platform. It’s a twin-turbo charged Inline 6 with direct injection (I personally like to call it a modern day 2jz-GTE). It is easily modify-able, and has very stout internals. With a simple $150 MHD Stage 1 ECU Flash, you can be pushing out 360-380hp at the crank and about 380-400tq. The issues with the N54 engine is not the engine itself. The internal of the N54 are bulletproof, and even the timing chain system is pretty stout. You won’t hear many stories of the N54 spinning a rod bearing or a having timing chain failure unless it was running super high boost or was incorrectly tuned. The issues with the N54 are with external accessories which are the following:

Electric Water Pump & Thermostat: The N54 uses an electric water pump instead of a usual chain or belt driven mechanical water pump. The electric water pump brings a lot of great benefits. It warms the car up faster in those cold winter months. It keeps running after the engine is off to cool down the turbos after a spirited drive. Also because the engine is not running the water pump, it takes stress and load off the engine making it more gas efficient and powerful. However, one caveat to the electric water pump system is that it doesnt have the same shelf life as a traditional mechanical water pump. Expect to replace the Water Pump every 60k-80k, and the thermostat every other water pump change. Luckily the water pump is not to expensive. ECS sells a Water Pump and T-Stat kit for around $500 (includes BMW Genuine Coolant), and it about a 2-3 hour job. I said say this is routine maintnance like a Timing Belt job on some other cars, but the good thing is if it goes out it wont ruin your engine.

Carbon Build-Up on Intake Valves: This is a very common issue, but it’s not N54 specific. Because the N54 has direct injection, it shoots fuel right into the cylinders. Great for power and efficiency, but not good for the keeping the intake valves clean. On multi-port injected cars, gasoline is constantly shooting on the intake valves. Gasoline is a great solvent, so it keeps the intake valves clean. Direct injected engine’s intake valves will never be touched by gas, so eventually they will get carbonized by the by-products from the combustion chamber. Carbon build up on the intake valves can cause throttle lag, loss of power and fuel economy, misfiring under load, and even valve-train noise. BMW recommends Walnut shell blasting the intake valves every 40k. You can do it yourself by buying the walnut blasting machine for around $250, or you can get it done by an Indy. Pricing ranges from $275-$500.

HPFP: The high pressure fuel pump is another common issue. The HPFP can have faults causing a long crank, stuttering or loss of power under throttle, or just causing the car to stall out of nowhere and not start back up. A recall was issued by BMW and they extended their warranty on the fuel pump for 10yr/120k miles. For owners that have over 120k miles, the HPFP is not that difficult to replace and the pump is around $400 for replacement.

Fuel Injectors: Injectors are common to fail also. They have had over 10 revision, but are still known to fail. Symptoms are intermittent misfires and loss of power. If you were lucky enough to buy one between late 2009 and early 2010, you should have a 10yr/120k mile warranty on the injectors. If you don’t have a warranty, the labor to replace them is fairly easy, and they can be had for around $850-$1000 for a set of index 12 revised injectors.

Oil Filter Housing Gasket or OFHG: The Oil Filter Housing gasket is a known gasket that can leak on the N54 powered cars. It can either leak internally causing a oil and coolant mixture, or it can leak externally causing oil to get onto the drive belt components. Ways to spot an OFHG leak is to check around the Oil filter housing for oil pooling, and check around the block for oil stains or seepage. Also if you notice coolant and oil mixture, most likely its due to a OFHG internal leak. This gaskets itself is cheap ($9), and its not that hard to replaced if your good with a wrench. This is a gasket I would recommend replace ASAP if you spot it because it can cause oil to get on the serpentine belt and cause the infamous Belt Shredding which I will explain in the next topic

Serpentine Belt Shredding: The N54 is known for eating belts , but the N54 will literally eat belts internally. If a belt shreds, the belt can get sucked inside the front main seal by the oil pump. It has been stories of a belt getting sucked all the way into oil pickup causing the timing chain to break thus meaning catastrophic engine failure. There are 2 ways this can happen. On early build 335i (2007 to early 2008) The subframe was dangerously close to the power steering pulley. Overtime when the motor mount would lose its strength, the engine would have excessive play during hard cornering or acceleration. This would cause the powersteering pulley to hit the subframe causing the belt to shred. The good thing is however, BMW updated the subframe with a notch for the power steering pulley in late 2008 builds. The second way is explained in my above topic, and it can happen to any car any year. To prevent this from happening, check your serpentine belt regularly for any type of abnormal wear or width loss. Also check your belt for any type of oil stains or oil around the block area. Also change your belt every 15k-30k for preventive maintenance. The belts are around $20-40, and are not hard at all to change with the right tools. If you have an early build model, you can upgrade your motor mount to the 335is version. It’s stiffer and prevents the motor from excessive movement under hard driving situations.

Valve Cover & Gaskets: The Valve Covers and Valve Cover gaskets are another gasket that’s know to crack over time. Some can fail as early as 25k miles (mines failed at 27k). The usual symptom is burning oil smell from exhaust. Also when you pull your coils, you will see oil pooling in the spark plug holes. The way to tell if the valve cover is cracked is to check around cylinder 2 and 3 for oil seepage or visual crack. The valve cover gasket replacement is not too bad to do (5 on a scale of 1-10), and the gasket is only around $30. The valve cover is around $400.

Oil Pan Gasket: Ahh the big daddy, and the one I’m not looking forward to doing when the times comes. The oil pan gasket is known to leak on higher mileage N54s between 80-120k. For most cars its a simple job, but not on the N54 engine. The oil pan sits right above the subframe, and in order to get the pan out you have to remove the subframe. This job from what I heard is pretty labor intensive. It’s not hard, but its just time consuming. If your oil pan starts leaking, I’d recommend doing some other maintnance and modification at the same time such as catless downpipes, water pump/T-stat, or turbo upgrade/replacement

Turbo Rattle and Failure Prevention: The turbos on the N54 are good for what they are, and they are under-boosted from the factory With the stock tune, they are only putting out 8psi. They can reliably run 15psi with no issues. They are some people putting out 23psi with fueling modifications. However, they do have some weak points. Over time, the wastegaste arms tend to get loose and rattle. This can cause a rattle noise when lifting the throttle, 30FF Boost leak code, and eventually causing the turbos to not hold boost at all. However, there are owner who have had wastegate rattle for over 20k miles and their cars still drive fine and hold full boost. There are also tuning mods to reduce the symptoms of wastegate rattle, but the only way to fix it correctly is turbo replacement. BMW did give a 8yr/82k mile warranty on wastegate rattle. A experienced BMW mechanic once told me turbos are like a e-cigarette, the more you use it the least time its going to last. I agreed, and to add on there are ways to prolong the life of your turbos by doing the following:

Change your oil every 5-7k miles with high quality oil. Oil gets broken down fast in this engine due to the high heat and gasoline blow-by. DO NOT follow the 15k miles interval. Eventually oil will get broken down with deposits resulting in sludge. This will eventually clog up the turbo oil lines cause the turbo to be starved of oil and fail.

Stay out of the boost until your oil temperature get to 180* or higher. I can’t stress this enough. Cold oil does not flow as well as hot oil. Imagine lubricating a wheel spinning at 50k rpms with molasses.

Keep your battery fully charged or replace when it’s bad. Cooling of the turbos is the main reason your water pump runs after you cut the car off after a spirited night of driving. However, if your battery voltage is too low, it will shut the water pump down so you will be able to start your car the next morning. If your turbos are not getting properly cooled, it will reduce the lifespan of them

One good thing is that turbo replacement and rebuilding is becoming less expensive. You can have your stock turbos rebuilt for around $800 or buy new stock ones with upgraded internals for around $1300. The labor is intensive however. It also requires dropping the subframe and removal of a lot components and downpipes. I’d recommend if your doing a turbo replacement to do the oil pan gasket, catless downpipes, and water pump job if it’s going bad.


This concludes the first part of my guide. As I stated earlier, the N54 powered 335i is a great car, but it does have it’s quirks. If you are a potential buy of the 335i with an N54, id recommend looking for a late 2009 or 2010. I will update this thread tomorrow with an in-depth buyers guide and what to look for when buying a N54 powered 335i. Stay Tuned


UPDATED WITH GUIDE FOR LOOKING FOR A 335I



Guide to looking for a 335i:

I had a little time today to add some more information to my guide. So here is my buyer’s guide to looking for a 335i.

BE PATIENT!!!
Please take it from me. Be patient and try to find a good one. Even if the first on you see is beautiful, and drives great, go home and think about it first. This not just with a 335i, but with any car purchase. I have rushed into many car purchases, and the next day I was remorseful because the car was a complete nightmare. For example: I went to look at a Acura TSX and bought it because it looked and drove great. I got home, and found out the title was rebuilt. The next car I purchased was a 2006 Infiniti G35, and 2 days later it needed over $2k in body and mechanical repairs. So Please fo not rush into your car buying decision.

Don’t always buy into the “Lower Miles=Better Reliability”

In my opinion high mile cars tend to be better buys than low mile cars, especially with the 335i. The only time it’s better to buy a lower mileage 335i is if it has a CPO or Dealer Warranty on it. Buying one with 30-50k with no warranty is a bad thing to do because you putting yourself in the mileage range where most of the problematic things start failing (Injectors, HPFP, Valve Cover Gaskets, Oil Filter Housing Gasket, Water Pump, etc). I’d say the best mileage to buy this car is around 70k, that way know most the problematic stuff has been taking car of by the previous owner. I can also speak from experience with the Low Mileage car being a worse buy. The G35 I mentioned early that needed over $2k in work ONLY had 52k miles.


Service History Records

First thing first with buying a 335i is that you get a copy of the service/maintnance records of the car. This will help you know how well the car was maintained. It will also give you rest-assurance that most the problematic things I mentioned earlier in this guide were recently repaired or replaced. You can find a brief overview and list by pulling up the carfax on the car, but in some cases there wouldn’t be any records listed. If the dealer or owner of the car doesn’t have any service or maintenance history records, don’t even waste you time test driving. There are a lot of 335is out there, and you don’t want to be stuck with a problematic one.

I looked at four 335i before I bought mine. The first one I looked at a dealer was a beautiful white/ red interior 2008 335xi. Only had 74k miles, and it had a nice sounding magnaflow exhaust. I was temped, but I asked if they had any service records for the car, and the salesman said there were no records. So I left shortly after.

The one I currently own, the person I bought it from gave me a book of service history records, and it just got of CPO. Also the water pump was replaced 5k before I bought it, so it was a good buy.

Check for leaks and noises

If you don’t have a mechanic or inspector going out with you to check a 335i out, then follow these guidelines. Bring a high lumen LED flash light to check for oil and coolant leaks. Take the car for a spirited test drive, and them come back and open the hood. Smell around the engine bay for any Burning oil or Coolant (Maple Syrup) Smells. Then pull out you LED flash light and check the following:

• Inspect the serpentine belt for any cracks or oil degredation
• Check around the Oil Filter Housing Gasket for oil buildup or leaks
• Check around the valve cover for any leaks or cracks
• If the car has a DCI (Dual Cone Intake), you can easily look to bottom of the engine to see if you have a oil seepage around the oil pan gasket.
• Inspect all coolant hoses and the reservoir for any leaks or cracks
• Inspect the ChargePipe for cracks if it’s stock.

Check for Wastegate Rattle

Blip the throttle a few times, and listen for any rattle on RPM deceleration. Another way to check for Waste rattle is to disconnect the vacuum lines off the vaccum canisters located at the front of the engine then reconnect them. If you hear any type of noise or rattle when you reconnect them, that’s most likely wastegate rattle.

Check for misfires or any type of hesistation while drving:

While the car is idling, listen and feel for any type of stumbling or misfires. This could be signs of needing new spark plugs, coils, or injectors. Also while driving under load check for any hesitation or surging. That’s also signs of what I mentioned, and also signs of a failing High Pressure Fuel Pump.

Get you a K-Dcan Cable and MHD even before you buy a 335i

The reason why I say this is so you can scan the car for codes. The DME (ECU) is pretty good at finding faults and throwing the codes. Having a K-Dcan Cable, an Android Device, and MHD could help you save from later headaches. It could tell you if the car has a misfire, a failing HPFP, O2 sensor, and other things.


If you end up buying one that you like and everything looks good, still negotiate on the price. You want to have about $2-3k put up for some just in case maintenance, and of course some mods.


So this concludes my guide to looking for and buying a 335i. I will be adding more soon. As I said before.

[DonDre]

reserved

[6ixSpd]

Fantastic! Now let's pray the n00bs actually check this out before posting redundant stuff.

[DonDre]

yea that the point of this thread. I want to get noobs to read this first before posting up the forum with questions or possibly getting roasted lol.

[ATLIEN]

Good stuff! I replaced my battery and registered it last night after months of the low battery symbol coming on. I had a somewhat long crank even after having my HPFP replaced and since the battery change the long crank is gone. I am hoping that was the cure so I can scratch injectors off of my list of repairs. Next up for me is carbon blasting and oil pan gasket.

[DonDre]

Yea definetly get the carbon blasting, it made a big difference in the car and the way it drives.

[jt335i]

Good write up. Admins need to put this as a sticky or somewhere easy to see for newbies car searching.

[mcunni]

Thanks I've been looking around for one of these for the past few weeks

[Jarrod]

This should be a sticky.

[PKL]

Great write up, thanks! I just got a 2013 335is

[PKL]

To the OP, I would super appreciate a section that specifies which issues might have been corrected over time? Like what years have specific issues, and what years might those issues be less likely to happen? Hope that makes sense.

[DonDre]

I will be doing that soon. I know a few things have been updated on the N54 in later model years

[Corno_Baldwin]

Good write-up -

But let the n00bs get roasted. Lol - they need to learn how to use google! No need to hold the silver spoon in their mouth.

All kidding aside, thanks for putting the time into this. It's nice having all the info in one place.

[DonDre]

Lol yea your right about the noobs. Some off them need a good roasting. I'm really just trying to help put owners like me want to do research and it's scattered all over the place.

Also pros and experts: if there's any info that wrong or misinterpreted let me know and I'll update.

[tgreer]

Thanks for this. Really wish I'd seen this before I picked up my E92 335i at the start of the month. Recurring 30FF issues!

[DonDre]

Did you check your charge pipe?

[HomoPirate]

Great write up with details!

[tgreer]

Originally Posted by DonDre

Did you check your charge pipe?

The pipe from the 2 turbos which feeds the intercooler was swapped out as it had a crack, however that still hasn't resolved it. Need to investigate in more detail, garage claims they leak tested all the boost + vacuum pipes, however I'm not confident that did.

edit: I'll check the charge pipe myself over the weekend, see what I can see.

[ZNITE]

[DonDre]

Originally Posted by tgreer

The pipe from the 2 turbos which feeds the intercooler was swapped out as it had a crack, however that still hasn't resolved it. Need to investigate in more detail, garage claims they leak tested all the boost + vacuum pipes, however I'm not confident that did.

edit: I'll check the charge pipe myself over the weekend, see what I can see.

Is your charge pipe stock or aftermarket

[BashShah]

After reading this, you would think no one would buy such a fun car.
Lol

[superadvance]

Originally Posted by DarkNemesis

After reading this, you would think no one would buy such a fun car.
Lol

Oh I definitely still want one.... It's just a searching game currently for the right one.