BMW M42 and M44 Engines. Disa Valve.

[8thvision]

In this guide we are going to show you how to diagnose and repair a damaged or faulty DISA Valve, a common problem in BMW M42 and M44 Engines.



Part Info
The DISA Valve is a large actuating valve located on the driver side of the lower intake manifold.
This Valve is responsible for controlling the variable length in the intake manifold. It is designed to provide improved torque at lower RPM's by remaining closed keeping the intake length long, and improved horsepower at higher RPM's by opening thus shortening intake length.

Diagnosis
The DISA Valve is fairly simple to diagnose and can be done effectively at home.

First Check the intake manifold for any obvious obstructions such as a clogged air filter or throttle body. As these can cause loss of power and other symptoms similar to the DISA valve.
when cleared move on to the DISA valve itself. With the motor running simply listen.

Now, while A faulty DISA Valve may cause a loss of power this can be intermittent and hard to detect at home.
The defining characteristic of a bad DISA valve is a very noticeable rattling sound. The rattling mostly occurs from 1500-2500RPM's and can be described as sand being sucked into the manifold.

Once you have diagnosed the valve you should consider either replacing or repairing it.

The DISA valve is a very expensive part, usually priced over $200.
Luckily repairing the valve is a relatively simple task and can also be done at home with one of our affordable repair kits found Here.

We also offer the replacement DISA valves at competitive prices found Here.

Installation Guide

Tools required.
Needle nose Pliers
small flat-head screwdriver
small ziptie (optional)

Removal.
The DISA valve is located on the left (driver side) of the lower intake manifold, it is held in place by 2 bolts.

Step 1
Disconnect the wiring harness (electrical connector) on the top right of the Valve, and remove the dust cover (if applicable).

Step 2
Remove Both retaining bolts one secured near the bottom center the other near the top right.
The unit should now come free. Take care not to damage the valve flap or its housing when removing, do not remove at an angle.

please note If you have purchased a replacement you can skip the rest of the guide and simply install the new DISA valve in the reverse order of removal.

Repairing The DISA valve

Step 1
Remove the pin located at the bottom of the flap, this pin is held in place by pressure only and can be pulled out, please note while the pin may pose some difficulty it is not recommended to use any kind of lubricant. We suggest using the small flat head to pry the pin up far enough to allow the pliers a better grip.

Step 2
Using the small flat-head screwdriver Remove the small cover on the face (outside) of the unit. this cover is held in place by small clips, sliding the screw-driver in through the top and applying a small amount of pressure to the cover should easily free it. the cover is located roughly in between the mounting bolt holes, it is easily noticed.

Step 3
Using the Needle nose pliers. remove the small actuating arm this arm is held in place by the cover you just removed and a small ring. the ring and arm should simply slide up and off of small stud. again please note, do not use any lubricants, some can damage the electrical components others can damage the plastic housing of the whole unit.

Step 4
Remove actuating gear. this gear is the main component and source of the rattling sound. With the flap held in the closed position. use the pliers to pull the unit up, some difficulty is expected here. you may use a zip tie to secure the flap, remember this component is being replaced you may use a flat head screw driver to pry it out, take care not to damage the rest of the unit.

Step 5
With the gear successfully removed, the flap can now be entirely removed. the flap is held inplace by the pin (you have removed earlier) and the gear (you have just removed) once the flap is removed you may reassemble the unit with the new parts from the repair kit.