TeeJay3800 Posted June 30, 2013 Report Share Posted June 30, 2013 Hi folks, first post here in a long time! About 3 weeks ago I bought a mint '06 Monte Carlo SS with the 5.3 LS4 and 87k miles. The only mod so far is Hooker Aero Chamber mufflers. Since day one the engine has made a noticeable clicking sound when in 4 cylinder mode (only at low speed...can't hear it on the freeway). Then today on the freeway I noticed a large puff of blue smoke coming out of the exhaust when the engine switches from 4 cyl to 8 cyl mode. This only happens when on the gas a little, not while coasting. The blue smoke goes away after a second or two. Are the noise and smoke related and what exactly is the problem here? I'd like some input before I take it back to the dealer. Quote Link to comment Share on other sites More sharing options...
jman093 Posted June 30, 2013 Report Share Posted June 30, 2013 Not familiar at all with the LS4, but I've heard the LS4 uses oil, and that disabling the MDS prevents the oil consumption. Maybe it's just normal, but the old mufflers trapped it a little better? Quote Link to comment Share on other sites More sharing options...
carkhz316 Posted June 30, 2013 Report Share Posted June 30, 2013 If you want this motor to last, find someone to tune out the D.O.D. (Displacement On Demand). My brother had a '08 GXP up until recently, and it used oil. He got rid of it before we ended up doing anything with it. A mutual friend had an '06 GXP, and used his extended warranty to cover an engine teardown that included new pistons and rings. I guess when they burn oil for too long, the coking and carbon ends up wrecking them. The culprit is the oil pressure release valve that activated when in 4 cylinder mode. This relief valve is pointed right at the bottom of the cylinder(s). There is an updated oil pan gasket with a built in shield that blocks off the spray of oil, but through testing by some members on the LS4 forums, it doens't seem to curb the oil consumption much. The only way to eliminate it is to tune the PCM to turn of DOD. This eliminates the oil consumption. Also, it's not like the mileage really changes with DOD; it's kind of a joke really. Granted my brother and our mutual friend both drive spiritedly, their mileage didn't really change even when they were driving normal. So, if you want to save this car, turn of the DOD Edit: I'm not sure what your clicking noise is all about, but I'm sure it's all related. Quote Link to comment Share on other sites More sharing options...
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