Hey there fellow LG4 owners. Well, Most of you may know this already, but I figured I should post it just incase, as it made my day. We all know about the heat riser that bolts inbetween the pass side exhaust manifold and the y-pipe. What i ever knew is that they things can sometimes not get vacuum, and as a result, get stuck shut. Well, I changed the temp controlled switch and really did not notice any change. But today I was beggining to think that it was infact the riser itself. I ran a length of vacuum line and tested it, it worked. Well, long story short, I ended up bypassing the switch all together, and BOOM, what a difference in sound, performance..... This car can finally breathe. I just wanted to post and let you guys know. as I have been complaining about crappy mileage lately and I have no doubt that this will help me get some more miles per gallon. I don't know why all the sensors on my motor that are coolant activated seem to not work for long at all, if ever. I have now gone through 3 fan switches in the 2 years I have owned this car. I rigged up a manual switch, but it still pisses me off that these things keep going out. Well, I hope someone gets something outa this!

Will

 

Thanks dude ill check it out

 

Thanks. Saving this one for when the Formula gets home from work tonight.

 

Um..... vacuum CLOSES the valve. Lack of vacuum OPENS it. So if you just unplug it, it's wide open (assuming it's not physically stuck)

I have seen one-way vacuum valves and such get stuck and keep it closed all the time, however.

 

i took the blow torch to mine and cut that flap out