181
CID (3.0L) 4 CYLINDER GM ENGINE
SERVICE MANUAL NUMBER 26
IMPORTANT: The following preload adjustment must be done slowly to allow lifter to
adjust itself, thus preventing possibility of the valve head contacting the top of
piston, which may result in internal damage and/or bent push rods.
5.
6.
7.
Repeat Steps 2-4 to adjust other valves.
Install rocker arm cover, torque to 40 lb-in. (4.5 Nm).
Adjust carburetor idle mixture and idle speed. Check for leaks.
Hydraulic Valve Lifters
Hydraulic valve lifters require little attention. Lifters are extremely simple in design.
Normally, readjustments are not necessary and servicing requires only that care and
cleanliness be exercised in the handling of parts.
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:
•
•
Excessive varnish or carbon deposit, causing abnormal stickiness.
Galling or “pickup” between plunger and bore of lifter body, usually caused by an abra-
sive piece of dirt or metal wedged between plunger and lifter body.
2.
•
Moderate rapping noise - probable causes are:
Excessively high leakdown rate.
Leaky check valve seat.
•
•
Improper adjustment.
3.
General noise throughout valve train - this will, in most cases, be a definite indication
of insufficient oil supply or improper adjustment.
4.
•
Intermittent clicking - probable causes are:
A microscopic piece of dirt momentarily caught between ball seat and check valve ball.
In rare cases, ball itself may be out of round or have a flat spot.
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., exists in one unit, it probably exists in all units. It would only be a matter of time
before all lifters caused trouble.
Index
Page 3A-20
90-861329--1 MARCH 1999
| Categories | Mercury MerCruiser Manuals |
|---|---|
| Tags | Mercury MerCruiser 181 CID |
| Model Year | 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 |
| Download File |
|
| Document File Type | |
| Copyright | Attribution Non-commercial |
(6 votes, average: 5 out of 5)
Marine readers have rated Mercury MerCruiser GM 4 Cylinder 181 cid 3.0L Marine Engines Service Manual Number 26 5.0 out of 5.0 based on 6 product reviews. Thanks for sharing this material. Helps a lot after suffering with bad mechanics. spend too much money and nothing very good
great manual, makes impossible jobs possible. without a manual you can not do the job, a must have.
Great resource. Excellent information provided.
Need help to install automate choke
Need help to instal automate choke