View Full Version : injectors

06-07-2006, 08:16 PM
could the fuel injectors in a 04 cobra make enough noise for me to think im hearing a possible lifter noise :stupid: :D :tomcat:

06-07-2006, 09:46 PM
yes...they do make a lot of noise...

06-08-2006, 07:19 AM
Yes and no.... They do make a distinct sound but will have a certain frequency since they are firing in sequence. A lifter or valve lash adjuster may tap periodically at a different rate since it may only affect one valve. Do you hear it when cold or all the time? There is a slight piston slap that may occur when the motor is cold but should not sound like a Cummins Diesel at any point in time. IF you hear a knonk or tap (not detonation) it may be a collaped valve lash adjuster lacking sufficient oil pressure. If it just started it may be cured with solvents (motor flush) in the oil followed immediatly by an oil change. Also, the PCV valve will make some noise as well. The EGR will make a loud clicking sound when it opens and closes but it has a slow response when it is operating (sounds like the clutch engaging on the AC compressor).