The cam and lifters were replaced 40k miles (10 years) ago. Between 2019 and 2024 the car was sitting because of major engine damage and the last 3 years the intake and heads were off leaving the lifters exposed. Since the lifters were sitting exposed to the air and moisture through all weather conditions (the hood was closed so they were not wet) I suspect some might have issues and causes the ticking/knocking noise I have had ever since i rebuilt the engine. I have not found any cam lobes that look damaged, but it is hard to tell since i have not removed the cam. The bottom of the old lifters look ok. It is also possible the parts used by that mechanic were bad quality since the timing chain that was replaced that time is quite loose.

If I just replace the lifters will this cause issues? Do I have to break them in?

 

Yes, breakin is required, no other damage if done properly.

 

What is the break in procedure?

 

old cam new lifters ok
Old lifters new cam not ok
just soak the lifters in oil for 24 hours before installing

 

I put new lifers on a cam pulled out of a 4.6 with sub 85,xxx miles.

My only break in procedure (along with new cam/bottom end bearings and rings) was to tell the little lady to take it easy for a week. I'm assuming she didn't. She doesn't know what that term means.

Broke in with Rotella t4, changed oil and filter at 500 miles.

X2 on soaking in oil over night before install.

 

Once the engine starts bring it up to 3,000 RPM and hold it there for 30 minutes. The higher engine speed is needed for the oil pressure to get the lifters spin in and break in the new lifter faces on the cam. It's the standard break-in procedure from all the cam and lifter manufacturers. You can look it up on Crane Cams or competition cams or any place like that

 

actually you just need to drive it and vary the rpms

 

I also break in everything, 2 stroke/4 stroke with the same basic principal, don't maintain constant rpms or synthetic oil while seating new rings

There was an odd cam/lifter break in on my TDI PD diesel engine that require 30 mins at a constant 3000ish rpm with some special oil but I'm betting this didn't happen new from the VW assembly line.