A quick and simple way to help diagnose leaking head gaskets on any generation duramax w an egr cooler. Besides routine 'CO presence in coolant' test procedure and other similar methods, this basically condemns head gaskets almost certainly. All conditions considered equal head gaskets are the only other possible point of entry for carbon monoxide besides egr cooler. It is important to separate the egr riser enough so the drive pressure can't effectively enter cooler if it is leaking. Secondly, you want to make certain the engine sits w steady pressure on cooling system (does so on its own anyway) and egr cooler flange still separated so any coolant escaping cooler would come out the back for easy viewing evidence.
Diesel Performance Texas Home; Duramax 2004.5 – 2005 LLY EGR Upgrade Kits; Duramax 2004.5 – 2005 LLY EGR Upgrade Kits.
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