mercedessource Tech help - Diesel Purge can help you isolate the noise Internal engine noises can be very difficult to diagnose. A diesel engine can ping, cling, clang and bang, and all the time you are wondering just what is acceptable and what is not. Some knocking noises are normal and should be of no concern at all, while other deep noises can be a sure sign of impending doom. These are ...
The Idle Enrichment Screw controls the quantity of mixed air and fuel at idle. At idle, air is entering the engine at 5 locations (Fig. 47): 1. Around the throttle valve (that is just cracked open). 2. Through the air orifices in the Idle Jet. 3. Scavenged flow into the progression holes. 4. Through Idle Bypass Passage (if equipped). 5.