Audi Specific Specialties and Repairs

We offer a number of services for all generations and models of BMW’s and Minis.



BMW 135i, 335i, 535i and N54 Service List

Some things to expect when purchasing a twin turbo N54 BMW

Oil Leaks

Automatic Transmission

Cars will need to be serviced with new pan and fluid as well as Mechatronics seal and sleeve before 100k miles.

For the most part, all cars have had a few HPFP’s done by now and this doesn’t seem to be an issue anymore but if you are getting long cold starts and pressure drops in logs, its something to investigate.


Wastegate rattle both internal and external to the turbo will begin in some cases as early as 70k miles depending on a number of factors. Some things can directly cause this however like vacuum lines. Adding catless downpipes will magnify wastegate rattle issues. Failing wastegate thrust bearings can cause under/overboost conditions as the wastegate arms inside the turbo can Jam.


Caused by a number of different things from the PCV system to turbos. The valve cover PCV system can internally fail and cause significant smoking/consumption. Adding downpipes to the car further makes the smoking more apparent as the cats are no longer ‘filtering’ the smoke coming through them.

Fuel System

When modifying a vehicle to extremely high power levels, fueling needs become a concern. People are currently adding secondary in-tank pumps, secondary high-pressure pumps, and secondary direct port injection fuel rails as well as meth injection to compensate.

Cooling System


Expect to do vanos solenoids around 100k or sooner depending on how often the oil was changed. You can sometimes get away with cleaning them but typically vanos codes (2A87/2A88) will return. Worst case scenario is oil pressure to vanos hubs is being lost through cam trays (“hook ring seals”) Cam trays/ledges will need to be replaced as well as the updated Teflon cam seals.


If you’re into performance driving you will want an LSD. The factory open diff is sufficient for many but not most. There are a number of aftermarket alternatives available in this regard from gear type to clutch type.

“Limp Mode”

Arguably the most infuriating thing about these cars is they will frequently for a number of reasons engage limp or failsafe mode (half engine light). This can be caused by a number of things from a cooling system issue, under/over boost, vanos, fuel injection, misfire, etc.

Boost Leaks

Factory charge pipes going to the throttle body randomly fail at stock or elevated boost levels. The factory diverter valves can also leak. The hot side charge piping rarely leaks. Adding an intercooler also adds more couplers and clamps that can leak. Boost leaks can and will cause extra wear on the turbos as the ECU attempts to compensate for the loss of boost by working the turbos harder.

Oil System

Besides the aforementioned leaking issues, these engines are sometimes riddled with sludging issues because of BMW’s suggested oil change intervals. This can sometimes lead to stuff like Rod knock although this is fairly uncommon and seemingly random


Extremely overlooked and neglected, this simple thing can cause widespread havoc on your car. Keep it in good condition. When it’s starting to fail the IBS system will decouple the battery after you shut the car off thus turning the water pump off after the car shuts down that acts as a ‘turbo timer’ to cool the turbos down after shutdown. New batteries need to be ‘registered.’ If changing battery capacity, the battery needs to be ‘coded’ to CAS module.

DMTL pumps randomly fail. Emissions readiness monitors are sometimes extremely annoying to get to set.

The N54 car can be extremely fun and reliable if you maintain and build the car properly and with an end goal in mind. High power cars can be extremely frustrating to keep as a daily driver because of their nuisances.