Mercury MerCruiser GM V8 GM V8 454 CID 7.4L and 502 cid 8.2L Marine Engines Service Manual Number 23

454
CID (7.4L) / 502 CID (8.2L)
SERVICE MANUAL NUMBER 23
Locating Noisy Lifters
Locate a noisy  valve lifter by using a  piece of garden hose approximately  4 ft (1.2 m) in
length. Place one end of hose near end of each intake and exhaust valve, with other end
of hose to the ear. In this manner, sound is localized, making it easy to determine which lifter
is at fault.
Another method is to place a finger on face of valve spring retainer. If lifter is not functioning
properly, a distinct shock will be felt when valve returns to its seat.
General types of valve lifter noise are as follows:
1.
Hard rapping noise - usually caused by plunger becoming tight in bore of lifter body so
that return spring cannot push  plunger back up to working position. Probable causes
are:
a.   Excessive varnish or carbon deposit, causing abnormal stickiness.
b.   Galling or “pickup” between plunger and  bore of lifter body, usually caused by an
abrasive piece of dirt or metal wedged between plunger and lifter body.
2.
Moderate rapping noise - probable causes are:
a.   Excessively high leakdown rate.
b.   Leaky check valve seat.
c.   Improper adjustment.
3.
4.
General noise throughout valve train - this will, in most  cases, be a definite indication
of insufficient oil supply or improper adjustment.
Intermittent clicking - probable causes are:
a.   A microscopic piece of dirt momentarily caught between ball seat and check valve
ball.
b.   In rare cases, ball itself may be out of round or have a flat spot.
c.   Improper adjustment.
In most cases, where noise exists in one or more lifters, all lifter units should be removed,
disassembled, cleaned in solvent, reassembled and reinstalled in engine. If dirt, corrosion,
carbon, etc., is shown to exist in one unit, it more likely exists in all the units; thus it would
only be a matter of time before all lifters caused trouble.
Index
Page 3A-34
90-861326--1   MARCH 1999
Product Specification
CategoriesMercury MerCruiser Manuals
Tags,
Model Year1998, 1999, 2000, 2001
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Mercury MerCruiser GM V8 GM V8 454 CID 7.4L and 502 cid 8.2L Marine Engines Service Manual Number 23 SKU UPC Model
Matt on Apr 08, 2015.

Just need the manual. Wrote review. Can't technically review what I haven't seen yet...


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