How to Wash Your BMW Engine Bay & Diagnose Oil Leaks - Part 2 of 4

DIY GOALS: Degreasing and Cleaning Engine Bay, Checking for fluid and oil leaks

DIY TIME: 1 hour

DIY Special Tools: None needed (unless you want to remove the fan)

DIY COSTS: About $10 for Engine Degreaser, Engine Detailer, Armor-All, Aluminum Foil, Zip Lock Baggies and other cleaning agents that you may want to use.

The BMW M54 Engine and it's engine bay design are shared between several BMW Vehicles from 1998 through 2006. These are the E46 3 series, E39 5 series, Z3/Z4 3.0, X3/X5 3.0 and the early years E60 5 series.

So this DIY for washing the M54 engine and checking for basic Oil leaks can be applied to other BMW cars besides the E46 3 series. In the DIY when I refer to the M54 I am referencing to all the cars. That said this DIY for Engine washing can be used as a general guide for any modern era BMW vehicle.

I spent a lot of time looking for an online DIY for washing the Engine Bay of a car to find there was none.

There was lots of various advice ranging like lathering down the entire bay with degreaser and power hosing it to hell and back. I also read advice saying never use water on an engine bay and to just use a toothbrush and rag with some light degreaser and WD40 to clean the entire bay.

I did not have all week to clean the engine nor was I going to go in there like Rambo and power hose it down like many Youtube videos on engine washing tend to show.

After combing through some better information and talking with my friend at BMW's Mt Kisco Dealership in Westchester, NY I discovered the best method was the simplest, cheapest and most safe.

First lets clear up one popular engine washing debate:

1. Power hosing your car's engine bay is bad - This is both true and false. Some vehicles especially SUVs like Jeeps and Range Rovers are specifically designed with parts under the hood that can withstand a pressurized blast of water or the prolonged presence of water in the engine bay.

Alternators and other electrical components on these SUVs and cars can be hosed down with liquid water and the vehicle will start and drive perfect even with the engine still wet.

The alternator and "opened" electrical connectors in the M54 bay may or may not be designed to be watered down but do not take any chances. Also since the forever-dirty and leaking Power Steering fluid reservoir sits an inch or two above the alternator it will usually always need several bouts of degreasing and hosing down. So it is best to assume your M54 or BMW alternator MUST be covered up to be protected from not only water but also from the chunky grime and gunk that will be hosed off of the power steering housing.

Keep in mind that all cars and engine bays are created different even between BMW vehicles so power hosing may be fine for some cars but for other cars it may not.


That said, besides DIYing this job yourself, the BMW Dealership (They charge $125 and bill it under Car Spa) is probably the best place to get this risky labor done on your car since they would know what parts can or can't get wet. Whereas a car wash employee that makes $5 per hour who usually power hose engine bays when detailing cars may not remember to put your car on a pedestal as he drags the hose towards your open engine bay.

Category:

Autos & Vehicles

Tags:

• degreaser
• degreasing
• washing
• engine
• bay
• Oil
• Leak
• BMW
• X3
• X5
• E39
• M54
• E46
• 330i
• 325i
• 335i
• 330ci
• 330xi
• 325xu
• 328i