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Old 04-24-2013, 08:10 PM   #60
Blktrax
Scooby Newbie
 
Member#: 220971
Join Date: Aug 2009
Chapter/Region: South East
Location: Havelock, NC
Vehicle:
2002 WRX 210K Mi.
Original Motor and Turbo

Default

I had this, then my computer decided to reboot randomly, so attempt#2.

The AVCS gets oil pressure from the cyl head before it gets to the Cams, the last pressure point before returning to the oil pan. I have two theroies:

1st would be a sticking or defective oil pressure relief in the new pump, but unlikely as the motor still runs, and hasn't spun a bearing yet.

2nd excessive bearing clearance on the cams, oil pressure is fed to them however is going to take the path of least resistance. If there is excessive clearance its going to press back out in to the head, and not pressurize the AVCS gear properly.


Ye 'ol book sayith:


Measurement of the camshaft journal oil clearance:
(1) Clean the bearing caps and camshaft journals.
(2) Place the camshafts on cylinder head.
(Without installing the valve rocker.)
(3) Place a plastigauge across each of the camshaft
journals.
(4) Gradually tighten the cap in at least two
stages in alphabetical sequence shown in the
figure, and then tighten to specified torque.
Do not turn the camshaft.
Tightening torque:


T1: 10 N
m (1.0 kgf-m, 7.2 ft-lb)
T2: 20 N
m (2.0 kgf-m, 14.5 ft-lb)

(5) Remove the bearing caps.
(6) Measure the widest point of plastigauge on
each journal. If the oil clearance exceeds the
limit, replace the camshaft. If necessary, replace
the camshaft caps and cylinder head as a set.
Standard:
0.037 — 0.072 mm (0.0015 — 0.0028 in)
Limit:
0.10 mm (0.0039 in)
(7) Completely remove the plastigauge.

5) Check the cam face condition; remove the minor
faults by grinding with oil stone. Measure the cam

height H, replace if the limit has been exceeded.




If your machine shop is good, you should have the clearances on your paperwork.
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