How to save money on a BMW DISA Valve
BMW’s from 2001-2012 contain a BMW DISA Valve to open a secondary passage in the intake manifold to change the length of the intake runner. DISA stands for Differentiated Intake System Actuator.
Why do you need a DISA valve?
In gasoline engines the intake valve opens during the intake phase to suck in air or an air/fuel mixture. This causes a rapid flow of air down the intake runner. When the valve closes the air slams to a screeching halt and forms a high pressure area behind the valve. The high pressure creates a wave that ricochets backwards up the intake runner. When it reaches the end of the runner, it bounces back towards the valve. If the timing is just right, that secondary wave arrives back at the valve just as it’s opening for another intake stroke. The extra pressure helps fill the cylinder. Unfortunately, the pressure wave only returns at the proper time in a very short RPM range.
So BMW added a BMW DISA Valve the PCM can switch intake paths depending on engine RPM. The BMW DISA Valve diverts the air back and forth between the two runners. The BMW DISA Valve is basically a butterfly valve that closes off the larger diameter runner at low engine RPMS and opens it at higher engine RPMs.
Other car makers utilize the same type of system but call it by a different name. Ford, calls it Intake Manifold Runner Control (IMRC). In older models they control the IMRC with a vacuum actuator. In newer models they use and electric motor. GM and Chrysler also have their own versions.
What causes a BMW DISA valve to fail?
The BMW DISA Valve itself is plastic and is opened and closed with a plastic shaft. Carbon build up in the intake manifold can deposit on the butterfly valve and shaft causing the shaft to break. BMW charges $350 for a new BMW DISA valve, even though only the shaft is broken.
Don’t replace the entire BMW DISA Valve, just replace the broken parts
Now you can buy aftermarket kits that include just the parts that break. Standard F66001 / F66002 / F66003 BMW DISA valve repair kits fit all 2012-97 BMWs and cost less than $50.
Just remove the old BMW DISA valve and disassemble. Replace the broken butterfly, shaft, O-ring and keeper with parts from the new BMW DISA valve kit. Reinstall on the engine and connect the vacuum lines and electrical connector. Clear the trouble code and you’re good to go.
©, 2016 Rick Muscoplat
Posted on by Rick Muscoplat