So I was checking my fuel injectors to see if I had a leaky one and I noticed this weird gash on my lower intake manifold. I don't understand how it got there because I know for a fact it was never there until I looked right now because I've taken that manifold off like four different times. It also doesn't look like it was hit by anything because it was smooth but it obviously is now missing some material at the very top where it meets up with the upper intake manifold. It's probably a 1/16" that's missing but do you think that's enough to cause a vacuum leak where those two surfaces meet up and sandwich the gasket in?

 

I guess that could cause something like that, but no guessing!
Try unplugging your IAC. If the engine drops to ~500RPM or almost dies, I'd say you're good
If it doesn't then you've got a vacuum leak and need to test that area with carb cleaner/propane, or use a stethoscope

 

Well I already have a slightly high idle from something else so unplugging the IAC isn't reliable enough test for me anyway. I'm getting like 18 in Mg on my vacuum gauge and I assume if I had a vacuum leak at the intake manifold it would be much lower than that but again that's not really solid answer. I've also smoke tested the engine and nothing has come out there but yet again that's not super reliable because it pulls air in with the hell of a lot more Force than a smoke machine put smoke into your engine and it could be a warm and cold situation also

 

Have you tried the carb cleaner/propane test?
18 inHg is definitely a good reading. The gauge doesn't flutter or anything when hooked up, does it?
If you're not experiencing lean conditions or any strange whine when the engine is running, it sounds to me like it might not be an issue...
Could be wrong though! If anyone else has gone through this, don't hesitate to weigh in

 

What do you all get for vacuum at idle? I swear to God I have a vacuum leak because I idle at like 900 and I have the manual transmission but the vacuum gauge, smoke test, propane test, all seem to say I don't but I can't figure out for the life of me then why I have such a high idle. I've been working on this for literally like a year and have come up with nothing