2003 GMC ENVOY SLT.
Question = When i turn the truck on in the morning,its makes a noise click, click,
click right under the temp control gauge by the switch for the 2wheel,4wheel
drive. What seems to be the problem. My friend says its the sensor.
Answer: The noise you are hearing is probably one of the heater A/C
actuators rotating under the dash. It could be for the mode door, or
temperature control door, or both. These will make a clicking type
sound when they move. If you're not experiencing any trouble with the
air conditioning or heat, then it is something you don't have to worry
about. It may just be a bit annoying. Depending on which one is
making the noise, it can be a very expensive repair with the labor
involved to get to it.
Problem with my 2004 GMC Envoy
Engine size = 4.2
Warning lights = low oil pressure stop engine.
GM Computer codes = p0016
Repairs for this problem = rechecked connectors, replaced oil pressure switch and cam sensor.
Did valve job on head due to burned exhaust valve in #3 cylinder. Checked and rotated timing chain
to align dark links on sprockets. Delphi on cam straight across front of cylinder head. Flats in rear
up. When first started up, ran great,came to full operating temp,drove down road came to stop and
got low oil pressure stop engine. Take off oil pressure normal. Oil pressure normal until you come to
a stop and now ses p0016.
Tech:
Assuming you are sure the crank did not move at any time, then the P0016 code may be set
because the "Crankshaft Variance Re-learn Procedure" was not done. This needs to be done
with a scan tool. Or it may be set because of the low oil pressure. Cylinder head work should
not of course affect oil pressure. Take an oil pressure reading just to be sure it is actually low.
About 6 PSI at hot idle will set the warning. Check to make sure the proper oil filter is installed,
no debre in the hole the pressure switch screws into. If all checks OK and pressure is low, I
would say this is an oil pump problem.