I have a 91 xj auto with 205xxx on the motor. Two weeks ago the cylinder head cracked. I replaced it today and now I hear a sort of pinging or random tap coming from under the hood (I think its the engine). It doesnt start till the aux fan kicks in and when i hit the throttle it goes away. Even with the cracked head it didnt make this noise. Im kinda scared to actually test drive it. Is it a low end Knock? If it is, is it safe to drive? What do yall think woulda caused it from my end? (when I was replacing the head)

 

sounds like a loose bolt??...this is coming from what i found from MY jeep and only an opinion but i develop a lower end knock and after doing some research found that a loose torque converter bolt could do make that noise..and sure enough it was

 

Ah will try that...