I had my new LBZ GMC K2500HD in for its first oil change the other day and was mentioning to the mechanic at GM about a ticking noise comeing from the rear of the drivers side front wheel well.
The mechanic could hear it as well and we investigated by taking a brand new Duramax out for a drive to warm it up so we could see if the same noise could be heard on it . We could not hear the same noise from this truck so while my truck was in for its routine maintenace visit they found a bulletin regarding this noise.
*** Bulletin number 02-06-01-022F (section 06 - engine /propulsion system) 11/30/2006 ***
It says in short................
This noise is caused by the relationship of the engine cylinder block, crankshaft journals, bearing inserts and the oil film. This relationship may allow a vibration that resonates through the cylinder block and is heard as a metallic ticking noise. The noise could be described as an irregular ticking or clacking sound, like random typing on a mechanical typewriter.
All Duramax diesel engines have this condition, however, some are more audible than others.
Testing and engine teardowns with this condition reveal no condition that would affect reliability or durability of this engine.
Dealers should not attempt to compare any customer vehicles exhibiting this noise with other similar vehicles as the noise is different form vehicle to vehicle.
This noise is a normal operating characteristic of the engine. This noise has no short or long term effects on the engine . Do not attempt repairs for this noise.
info numbers :
GMC 1-800-462-8782 USA
1-800-263-3777 Canada
Chev. 1-800-222-1020 USA
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Are we getting told a bunch of corporate BS !! ( like the GM " knock " in gas engines ) or is this the truth and there is no problem to worry about ??
hope this helps................
Fenmor , from Vancouver
Engine Ticking Noise 
Linear Mode
