The following article provides detailed instructions on replacing the PCV valve and crankcase breather system hoses on a BMW E46 3 series car. Even though we have used a 2003 BMW 325ci to perform this installation, this article can be applied to any E46 3 series vehicle produced from 1998-2006, including the 323i, 328i and 330i coupe, sedan and convertible.
A BMW E46 PCV valve replacement may be needed if your 1998-2006 3 series is running rough and displaying a “service engine” light on the dashboard.
As discussed in many of our other articles, the recurring “Achilles Heel” of BMW vehicles with the M52 and M54 6 cylinder engine is the aging of the plastic parts comprising the vehicle’s intake system. As these parts start to crack and rupture from engine heat and age, they suck unmetered air into the intake system causing error codes and dashboard lights. These leaks can be extremely frustrating; some of the parts are difficult to get to, and if the system is not reassembled with care even more leaks can be created.
The PCV valve and associated crankcase breather system in your BMW is actually a fairly simple arrangement. Its sole purpose is to relieve the pressure that builds up inside your engine’s crankcase by sucking out the gases, oil and water condensation produced during engine combustion. The PCV valve’s job is to separate these combustion byproducts; it channels fumes and vapor back into the intake manifold for further combustion and oil back to lubrication system via the dip stick tube.
Cracked or damaged pipes comprising the crankcase breather system are a major cause of vacuum leaks in BMW E46 intake systems. Not only will a damaged crankcase breather system cause a rough idling engine, it may also cause a variety of warning messages in your car including the SERVICE ENGINE SOON light on the dashboard and engine code faults 2882, 2883, 2986 and 2987 on your diagnostic scanner. If you are experiencing these issues, a BMW E46 PCV valve repair including replacement of the crankcase breather system is recommended in your vehicle.
A BMW E46 PCV valve replacement is unfortunately not as easy as other models since most of the plumbing that needs to be removed is under the intake manifold. You may find other articles that show a BMW E46 PCV valve repair being executed without partially removing the intake manifold, but we highly suggest our readers stay away from these “quick fixes”. Don’t be intimidated by partially removing the intake manifold to do this repair. In fact, think of this as an excellent opportunity to replace your intake manifold gaskets which are also prone to failure on this vehicle. In the following BMW E46 PCV valve replacement article we give you detailed step by step instructions on how to do the repair yourself in your own garage.
1. Crankcase PCV valve (required) – The PCV valve always needs to be replaced when overhauling the crankcase breather system in your BMW E46. We give you several choices based on your budget.
2. Crankcase ventilation hoses (required) – Always replace the hoses in your crankcase breather system when replacing the PCV valve. Replacing one without the other is like changing the oil in your car and not replacing the filter.
3. Intake manifold gaskets (required) – Since you will need to partially remove your intake manifold to do this repair, you must replace the gaskets. Intake manifold gaskets are a major source of vacuum leaks in the BMW E46 3 series and are cheap insurance against future issues with your intake system.
4. Air filter (optional) – Since the air filter assembly will have to be removed to do this repair, now is an excellent time to install a new filter. Compliment your freshly reconditioned intake system with a new air filter element.
5. Cabin filters (optional) – Now is also an excellent time to replace the cabin filter that will be removed during this repair. Keep the interior of your BMW E46 smelling fresh with an inexpensive cabin filter.
- To remove the intake manifold in your BMW E46, please refer to the disassembly steps in our article BMW E46 Intake Manifold Gasket Repair- 1998-2006 3 Series .
Replacing the PCV valve in your BMW E46 intake manifold is a relatively simple procedure. It is very important that the connecting tubing is routed correctly through the intake manifold…pay careful attention to our photos so you don’t have any problems during assembly.
- Once you have the intake manifold removed, use a bungy cord to carefully secure it on its side. This is a very handy way to access the bottom of the intake manifold where the PCV must be installed.
- Begin by attaching the connecting line to the pcv valve as shown in the image below. It is very important that the connecting line is attached exactly as shown in the image so it lines up with other pipes after installation. ***The connecting line is actually “threaded” and attaches to the PCV valve by screwing on with one turn. It is very important that you have a tight connection.
- Insert the PCV valve into the bottom of the manifold, routing the connecting line as shown in the following image.
- Continue to feed the connecting line through the manifold as shown in the following images.
- Install the return pipe onto top of manifold and attach to the connecting pipe as shown below. Attach other end of return pipe to intake manifold fitting.
- Attach the connecting pipe to its fitting on the intake manifold. The fitting is tight…try using a flat blade screwdriver and the palm of your hand to force the connection on. You will hear a “click” when the connection is made.
- Attach the crankcase vent (breather) pipe to the PCV valve as shown below.
- Reinstall the PCV valve in bottom of intake manifold with the two torx bolts.
- Attach one end of the lower vent hose to the fitting on the oil dipstick. The oil dipstick fitting is rather low in the engine, so use a flashlight to find it. It easier to attach the lower vent hose to the dipstick fitting if you use a little engine oil to lube up the end first.
- Make sure the lower vent hose is positioned up so it can connect to the PCV valve when the manifold is reinstalled.
Please note that reinstalling the intake manifold takes patience. Always walk away from the job and regroup if you find yourself trying to force parts together, or if you start getting irritated. There are many plastic parts in the intake system that can break from trying to “manhandle” an installation causing you more work and grief. Take your time…we can’t stress it enough!
- Please refer to our article BMW E46 Intake Manifold Gasket Repair- 1998-2006 3 Series for instruction on reinstalling the intake manifold.