Toyota Repair: 2.4L Engine Knock, warranty information booklet, powertrain warranty

Question
Hi, I have a 03 Camry 2.4 L with 68K miles and it sometimes makes a lot of valve train noise.  It comes and goes but seems to be "stuck" with the car until you shut it off.  Meaning I could hear it driving to work Monday and all the way there but then on the way home, nothing.  Could this be the intake manifold problem? Any other suggestions?

Thank You.

Answer
Yes, the intake manifold has been a source of the noise, it sounds just like an engine noise, toyota has issued a service bulletin:T-SB-0034-08: Intake Manifold Noise
This repair is covered under the Toyota Federal Emission Warranty. This warranty is in effect
for 36 months or 36,000 miles, whichever occurs first, from the vehicle’s in-service date.
For California specification vehicles sold, registered, and operated in California, Maine,
Massachusetts, and Vermont, this repair is covered under the California Emission Warranty,
which is 70 months or 70,000 miles, whichever occurs first, from the vehicle’s in-service date.
• The warranty department will continue to honor warranty claims under the Powertrain Warranty
for these components for 2002 – 2004 model year vehicles where it is listed as such in the
Owner’s Warranty Information booklet (refer to Warranty Policy Bulletin POL04–06).
•