Quote:

......Last method. I caution you on this, since it does require flame. Have a helper and fire extinguisher nearby, make darn sure you know what you are doing, and think and plan ahead to avoid bad things. Oaky, for the really plugged passages that are cast into the manifold with all sorts of twists, this method provides great results. It gets them really clean. First, remove everything near each end for access. Also make sure all flammable stuff is moved aside and there is no fuel nearby. Blow compressed air into the area and the intake to remove any fumes. Fire up your oxy/acetylene torch, preferably a small tip. Point it at the EGR end of the passage and get the deposits burning. Now, turn off the acetylene, so only the oxygen is coming out of the torch. This will cause the coal-like deposits to burn like charcoal and clear out the entire passage. It is also dangerous, so make sure you understand what you are doing and what are the possible issues that can happen. You might even want to take the intake manifold off the vehicle before attempting this. Clean carefully after and reassemble.



I've done this to open up plugged exhaust crossovers but only with the manifold removed and only on cast iron manifolds. I'd never try it installed on an engine and I'd be wary of trying it on an aluminum intake. The key to making this work is to have a gas pass through the passage. That way when the carbon starts burning it doesn't flash back on you.

"We live in a time when intelligent people are being silenced so that stupid people won't be offended".