How Do I Drain GH Intercooler?

[WarrenBoostit]

Hey everyone,
My car's approaching about 68k miles, and I've been wanting to drain the Gearhead intercooler for a while. The IC was put on by the prior owner, and in total probably has been on the car for four years. I've been suspecting some pre-ignition lately, and seeing as I don't see an access hole anywhere on the plastic underside of the passenger side of the car where the IC sits, I'm guessing it has never been drained. I've heard descriptions of where to cut the hole, but I'm still a bit confused on where exactly it should be, and would love a for-idiots explainer on how to properly get to it by cutting through the plastic underside.

When I pulled the map sensor before the throttle body today to clean it, I noticed a thin film of oil around the port the sensor sits in, furthering my suspicions of oil-based preignition, and besides, this is something I should've already taken care of a few maintenance events ago, so any help in this thread would be greatly appreciated. Thanks!

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Black 2018 SHO Non-PP | GH e30/AO Tune | PPE Catted Downpipes | DG2 Trans Mount | M-12405-35T plugs at .026 | 170 Tstat | 3 bar | H&R Springs | XDI-35 | Badges removed | Chrome delete | Fuel-it Bluetooth ethanol analyzer | GH IC | EPP Gen2 CAI | Noisemaker delete | MSD coils | Ceramic coating | Window Tint | EPP Hot Pipes | Black AR924 w/ General GMAX AS 05 255/45r20 | MRT axle back w/black tips

 

[Ta2dResqr]

It is straight down in the general area of the radiator drain on the passenger side. You will need to remove both of the under-body panels. You will be cutting through the radiator core support. Best way is with a bore-scope or camera of some sort if it is already installed. With is installed, an oscillating tool is probably going to be your best bet.

 

[WarrenBoostit]

Damn, was hoping I could just lazily cut through without having to remove anything, but that makes sense

 

[mattr66]

i used a 3/4 hole saw with a very shallow centering bit and came through everything. once i had a good support on the sides of the hole, I removed the centering bit.