Sounds like there may be trash in there..drop the blower motor out,get the debris out, put it back in...simple job...
If the noise is a squeaking sound, it could be coming from the bearings in the blower fan. It could also be coming from a worn bushing or bearing in the blower motor.
check heater blower motor blower wheel could be broken off The knocking comes from an Acctuator that has stripped out in the Hvac case. You Have to replace the acctuator to solve the problem.
because its either cold and not warmed up or you lifters are knocking but the would be a louder knocking sound
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Mine did the same, mine was a motor mount.
Engine rod? Engine bearing?
Possible cam chain tensioner has broke.these tensioners are none adjustable and sometimes brake causing a knocking sound in the motor
Engine knocking can be caused by numerous things. Having the incorrect spark plugs, carbon deposits on the cylinder walls, and being low on engine oil may all cause a knocking sound.
it might be a bent piton rod if you or water or somthing into the engine
Your blower motor relay went bad. You may also need to replace either the blower motor or one of the climate control sensors. If your blower motor squeals or makes a scraping sound it is going bad and will damage the blower motor relay. JQ
the blower motor is going bad it will stop working shortly
Most likely your motor is low on oil and is knocking from being over heated.