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Idle Control Valve (ICV)

38K views 0 replies 1 participant last post by  jjrichar 
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Idle Control Valve (ICV)

Link to other parts of the project
DIY: M54 engine disassembly

As the name suggests the ICV does the controlling of air going into the engine at idle. The throttle valve when fully closed is doesn't still allow a bit of air in, but most goes through the ICV.

I cut open this ICV years after doing this project. I learned a lot about the internals and how to clean and lubricate to ensure it operates effectively for much longer than it would otherwise. Link here:
DIY: Dissection of an ICV

The air going through the ICV has a completely different path to that going through the throttle assembly. It goes into small holes in the head that go only to one valve rather than to both. Apparently causes swirling in the combustion chamber and better combustion.





Removing it and cleaning it out every couple of years is good practice. It's also pretty simple. There are DIYs out there that explain how to do it well.

However, when I was playing with it, I found something that I'd not read before. Hopefully the photos show this. When installing the ICV you can push it in and think that it's all the way home, but in fact it's not. You've really got to push hard to get it right in there, and it's difficult to see if it's correctly seated or not. Maybe use a bit of lube to make it easier. You can put in the mounting screws OK with it in the wrong position, so it would be easy to think that you have re-installed it correctly. I removed and cleaned the ICV on my car a few years ago, and after seeing what I have, I'm not sure if I have done it correctly.

To get to the stage of this first photo, you will need to remove all of the air ducting going to the throttle assembly. (air box, MAF, Y junction etc)














 

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