I got my turbo bearings replaced and manifold bolts for exhaust side replaced too. now I have been seeing a drop of RPMs no when in park it was always right around 850 RPMs before now they have been going down to 830 and now down to 810 and 800 when just sitting in park. is this normal or is the vp44 going out now

VP44 idle speeds are controlled by the ECT sensor. So the warmer the coolant temperature the lower the idle speed.

 

Sorry, but just lower idle speeds don't mean there is a problem with the VP44.

ok good! I thought maybe it was going out again! thanks for the info moparman!!! ... and I got another question how rough should the idle be I know how loud they should be but it sound like it has such a bad tick some where and I have been thinking valves. I did have an exhaust leak when I had the manifold bolts replaced so could that have made the valves on the cylinder tick some?

Edited May 30, 201410 yr by fossum99

Valve lash? (intake 0.010" and exhaust 0.020")

 

Injectors pop tested?

 

Using cetane booster or a fuel additive?