I've recently bought a BMW Z3 roadster with a M44B19 engine in it, and have been hunting down a rough idle and really poor fuel economy since then. I've noticed that the DISA valve is starting to rattle, so I removed it and found the butterfly valve to have excess play in all directions. My question is, besides the rattling and obvious catastrophic failure, what are the symptoms of a DISA valve that is beginning to fail?
Failing DISA valve symptoms?
- Thread starter MReds98
- Start date
- Joined
- Nov 25, 2012
- Points
- 178
- Location
- Newport, South Wales,UK
- Model of Z
- Z3 M43 1.8 (1999) and Z4 E85 2.0i (2007)
Usually described as a clacking noise when they go bad as they flutter about causing the clacking sound. Best replaced before it self destructs and the engine eats the debris.
I had poor fuel economy and a slightly uneven idle due to air leaks in the pipes between the maff and the engine . Very common. Its worth looking for hidden splits with the engine running when you may hear the leak or change in engine noise. Mine showed up with an engine light. My code reader pointed to fuel trim faults caused by excess air being sucked in. I also had a code for a cam sensor which I changed a month later. The cam sensor wasn't affecting the running of the engine to any noticeable degree but i replaced it to be on the safe side.
- Joined
- Nov 25, 2012
- Points
- 178
- Location
- Newport, South Wales,UK
- Model of Z
- Z3 M43 1.8 (1999) and Z4 E85 2.0i (2007)
Personally I replaced mine with an oem one from BMW, rebuild kit all well and good but never going to be as good as a new one.
they seem hideously expensive new from bmw?
- Joined
- Nov 25, 2012
- Points
- 178
- Location
- Newport, South Wales,UK
- Model of Z
- Z3 M43 1.8 (1999) and Z4 E85 2.0i (2007)
Thats the downside fitting oem parts but they work straight out of the box, many pattern parts don't. Unfortunatley the two main componants, Oem Mafs and Disa valves on these cars are both expensive but buying pattern parts usually ends up by you paying twice when the pattern parts fail or don't work correcvtly.
