Is Rotella T 15-40 Too thick for sticking lifter??

I have a sticking lifter that usually I can't hear unless I'm stopped next to a wall or in a car wash port....Recently after I read about the ZDDP our beloved flat tappets need, I did a switch to Rotella T 15-40. Upon start up everything is quiet as I warm up it starts to tap pretty loud (my girlfriend noticed it..and that's bad) Is this oil too thick for a sticky lifter??

jeepman121 said:

I have a sticking lifter that usually I can't hear unless I'm stopped next to a wall or in a car wash port....Recently after I read about the ZDDP our beloved flat tappets need, I did a switch to Rotella T 15-40. Upon start up everything is quiet as I warm up it starts to tap pretty loud (my girlfriend noticed it..and that's bad) Is this oil too thick for a sticky lifter??

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I don't think its too thick, as I used to run it. However, it is my understanding that Shell reformulated Rotella last year and it no longer has any significant ZDDP in it.... ZDDP is truly important during the breakin of a flat tappet cam, but less important following breakin. It helps create a hardened alloy on the cam surface, as I understand it, but once that surface is present, the ZDDP is no longer necessary. I have gone the past 30k on Mobil 1 with no issues in my flat tappeted stroker, even with the infamous Crane 903 cam... :cheers:

Not again! LOL. http://www.naxja.org/forum/showthread.php?t=992751

well there ya go, searching rears its ugly head again!:cheers:

The way the oil effects your lifter noise depends on the cause of your lifter noise. if your lifter is not pumping up because of a restricted oil passage, thinner oil would make the lifter quieter. If the lifter isn't staying pumped up because it is worn out and won't hold oil pressure, then thicker oil would make it quieter.