hydraulic lifter wear
Posted: Sun Sep 09, 2018 9:06 am
Hi everybody-
first post here (or anywhere). I love this site though.
I recently did my 1st rebuild on a 2.0 type IV engine for my 1981 Vanagon. Did the standard cam run in for 20 minutes and have put about 1000 miles on the rebuild. Had the rotating mass balanced, rod ends rebushed, new bearings, pistons, cylinders (mahle), heads, pretty much the works. Runs well in my opinion except... if I let the engine idle at startup I hear what sounds like a very faint tap that goes away after about 3-5 minutes. Dropped the engine and pulled the oil pump to check for loose cam thrust and possible scoring on the cam gear bolts (new webcam, stock hydraulic grind). Checked flywheel endplay and tightened it up from .0045" to .003". No visible wear on the cam bolts and with the rocker arms off cant get the cam to jump at all axially - this is with rotating the cam back and forth by turning the big nut on the crank snout and also tapping it a bit with a rubber mallot. Runout on the gear face is around .002". Pulled the lifters and they all look fine in my opinion except for one - there is a slight divot spanning the face of the lifter. Can barely feel the indentation with my finger. Could this be the source of the problem? Cam lobes look good from what I could tell by looking through the lifter bores and rotating the cam.
Anyway I put the engine back in and have since put a few hundred more miles on it with no issues but that tap after startup is still there. Pulled the suspect lifter and its neighbor to get some photos. The suspect lifter is on #3 intake. At this point I'm thinking I should call up webcam and see if they will sell me a single lifter and see what happens. I wanted to get some other eyes on this though and seek some informed opinions. Should I just run the lifter as-is or replace it and see if that settles down the tap?
CHTs rarely get above 400 with a DD gauge on #3 plug. Typical temps are 370-380 at cruising speed (55-60 mph).
Here are a couple of pics of the lifters:
I would sincerely welcome thoughts/comments...the path gets dark sometimes when you don't have knowledgeable folks nearby to help out.
first post here (or anywhere). I love this site though.
I recently did my 1st rebuild on a 2.0 type IV engine for my 1981 Vanagon. Did the standard cam run in for 20 minutes and have put about 1000 miles on the rebuild. Had the rotating mass balanced, rod ends rebushed, new bearings, pistons, cylinders (mahle), heads, pretty much the works. Runs well in my opinion except... if I let the engine idle at startup I hear what sounds like a very faint tap that goes away after about 3-5 minutes. Dropped the engine and pulled the oil pump to check for loose cam thrust and possible scoring on the cam gear bolts (new webcam, stock hydraulic grind). Checked flywheel endplay and tightened it up from .0045" to .003". No visible wear on the cam bolts and with the rocker arms off cant get the cam to jump at all axially - this is with rotating the cam back and forth by turning the big nut on the crank snout and also tapping it a bit with a rubber mallot. Runout on the gear face is around .002". Pulled the lifters and they all look fine in my opinion except for one - there is a slight divot spanning the face of the lifter. Can barely feel the indentation with my finger. Could this be the source of the problem? Cam lobes look good from what I could tell by looking through the lifter bores and rotating the cam.
Anyway I put the engine back in and have since put a few hundred more miles on it with no issues but that tap after startup is still there. Pulled the suspect lifter and its neighbor to get some photos. The suspect lifter is on #3 intake. At this point I'm thinking I should call up webcam and see if they will sell me a single lifter and see what happens. I wanted to get some other eyes on this though and seek some informed opinions. Should I just run the lifter as-is or replace it and see if that settles down the tap?
CHTs rarely get above 400 with a DD gauge on #3 plug. Typical temps are 370-380 at cruising speed (55-60 mph).
Here are a couple of pics of the lifters:
I would sincerely welcome thoughts/comments...the path gets dark sometimes when you don't have knowledgeable folks nearby to help out.