2004-2007 Cadillac CTS-V Performance Mods Discussion, Problem with DMH low-profile electric cutouts in Cadillac CTS-V Series Forum - 2004 - 2007; Hey everyone!
I've had DMH "low profile" electric exhaust cutouts installed on my V for over 3 years now (probably ...
I've had DMH "low profile" electric exhaust cutouts installed on my V for over 3 years now (probably 25k miles since installation). They have absolutely been my favorite mod that I've done to the car (in combination with my headers and cat-deletes). Smiles/$$$ - the cutouts are the best investment I have ever made.
Unfortunately, unless I'm intentionally opening the cutouts (which I do a lot for obvious reasons), the cutouts don't seem to close very well anymore. As soon as I take my finger off of the [momentary] switch to close them the cutouts will immediately re-open a bit and make the car sound like a clapped out old camaro or something. I know that DMH has a poor reputation for service to customers (4 year warranty is only good if you can actually get a hold of him) - so I'm hoping some folks in the V community can help me fix this issue. I really don't want to remove the cutouts for good and cap the flanges...they are just too much fun. But I'm getting sick of pulling up next to cars and feeling like I'm driving a busted POS rather than the brute Cadillac that this is supposed to be.
So here is my problem. The butterfly "gate" doesn't seem to want to stay shut in the "closed" position. The butterfly gate is mounted to a spindle that sticks is inserted into the gate flange. One end of the spindle stops at the end of the flange, the other end of the spindle attached to a coupler that is part of the motor unit. I can very clearly see that (even with the cutouts in the "closed" position) that the spindle has some play in the valve flange. It's not much play, but enough that I think it clearly demonstrates that the powerful air pressure of the exhaust can force the valve to crack open and create the rattle.
I've posted two videos that explain what I'm talking about:
I've seen a few threads over the last few years where people have mentioned that there are some screws that work there way out (in the motor housing) and can be drilled out and replaced. I'm not really convinced that the motor housing is causing the problem - unless the motor is supposed to be providing some additional tension that forces the valve to seat closed and stay closed. I haven't drilled out the rivets to investigate because I wanted to get some input from the forums on if my loose spindle/flange is causing the rattle. If tension is required to seat the valve, then I guess I have no choice but to drill the rivets out and try to fix them.
Well I drilled out the rivets on one and tightened down the two motor screws) the only two screws that I could really see. I re-aligned everything and bolted it all back together. I couldn't push the butterfly gate backwards and forwards like I did in the 2nd video...so I was optimistic that the results would be good.
Of course, as soon as I started it up the exhaust forced the gate to open slightly and I'm back to square one...still leaking/rattling. The gate just has too much play in it to stay in one place. I wonder if I could shim in tight to stop the back-n-forth play that the gate spindle has against the gate flange.