#7
Timing chain job and all coolant pipes are all done 137k miles.
Hello my 2012 xj 5.0 n/a has a loud start up for about 5 seconds and then sounds fine when gets to low idle and drives great. Sounds like lifters or something up top, almost like a deep rubbery knock. We did the timing job, waterpump, coolant pipes, idler and tensioner pulley so far. No exhaust leaks. The chain was definitely was loose but I have driven it like that for a year now and the noise has never changed. Day of startup after timing job and it sounds exatcly the same! And now the mechanic is getting loud clicking from the a/c compressor (so he thinks)which has never happened belore. Is it a cam or a phaser? Crankshaft? I know the fuel injectors can be loud. What else can be noisy for about 5-10 seconds on start up? Oil starvation or hydraulic tensioner on chain not getting oil soon enough? Knock sensor maybe? Am I getting any oil pressure? Ive heard several that arent noisy like mine. What else makes noise or fails with the aj133 motor please? Thank you for any help!

 

Hard to say and you need a few more posts before you can post any audio files as that may help identify the problem?
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Take a video and upload it to YouTube (or something similar) and then share the link.