GM-GMC: Chevy S10 4x4 ZR5 4.3 litres Noise after Repair, engine oil additive, chevy s10

Question
QUESTION: Hi,
Last week I took my Chevy S10 4x4 ZR5 4.3 litres to Canadian tire to change 1 head light.  They made a visual inspection on my pick up and the recommended me to change the Intake Maniful Gasket and the water pump (was leaking) and they made me an estimate.  I purchased the parts there and went to a local mechanic shop (here in Edmonton, AB) to do the job.  Now my car has a constant noise, like a continuos bee flying but when I push the gas I cannot hear it.  I just realized that the cruise control is not working anymore...  I took the pick up back to the shop and told them that my car didn't have any kind of noise before, but they do not want to do nothing else about that.  What could be the problem? Where should I take my pick up to have it fix.  Thank you!!

ANSWER: That is not an uncommon occurance.  It is likely the lifters that are making noise, unfortunately the intake would need to be removed again to replace the lifters.  You could try an engine oil additive like lucas oil or something and it may provide some relief.  As for the cruise control, the throttle linkages were likely disconnected to repair the intake gaskets.  Trace the cable from the cruise control unit to the throttle to ensure it is connected.  The cruise could be something that the original repair shop is responsible for, but the lifter noise is something that, if they new the engine and the repair history they could have warned you about prior to starting the repair.  As for who should fix it, find someone you trust is all I can suggest.
Hope this helps.

---------- FOLLOW-UP ----------

QUESTION: Hi again,
Thank you very much for your answer.  I forgot to mention you that the noise is only listenable inside the cabin of the truck, it is more clear in front of the driver's seat,   The noise is like a vibration noise and it happen when the car is idle (no when I push the gas).  It is not really a loud noise, but it annoys me.  I tried to listen the engine outside but I couldn't hear the noise. Is it the kind of noise the lifters make, or the lifters are more noisy?  Thank you very much for your help!!!

Answer
That changes things alot.  If the noise is not MORE noticable under the hood, I can assure you it is not your lifters.  Check for something rattling against the firewall in your engine compartment or for something loose in your dash area.  It is difficult to say what it is that is making the noise.  I appologize for misleading you about your lifter, but what you described before it made sense.
Hope this helps