| ABNORMAL CYLINDER WALL WEAR |
Abnormal Cylinder Wall Wear
Cylinder wall wear falls into two categories. The first type is wear that occurs over the life of the engine. The second kind is rapid wear that limits the engine's life to just a few thousand miles or less.
Premature engine failure due to excessive and rapid cylinder wall wear in the ring travel area is usually due to dirt contamination of the intake charge or the lubricating oil supply (see illustration).
If the excessive wear is located at the top of the cylinder bore only, it was caused by dirt particles entering the engine through the intake system. A defective air filtration system is usually the cause. On long, multi-piece air intake systems be sure to check each of the connections for possible leaks.
If the excessive wear is located at the bottom and the top of the cylinder bore, it is caused by dirt particles in the lubricating oil supply. A PCV system that is open to the atmosphere, or a dipstick that is not properly seated is usually the cause.
Another indication of dirt contamination are vertical scratches on the face of the piston rings. Scratches may also be found on the sides of the rings and on the ring lands. Often the ring face edges become razor sharp.
The AERA Technical Committee |
| DOUBLE LIP OIL SEAL INSTALLATION |
Double Lip Oil Seal Installation Information
Before installing any double lip oil seal, the groove between the
seal lips must be filled with a lubricant such Quaker State
multi-purpose kMoly Lubricant BLGT No. 2, Texaco 2301 RB, or
equivalent.
Failure to do this may result in dry running of the outer lip and
will cause seal failure.
The AERA Technical Committee
September 1976 - SPB 34
##END## |
| REVISED CYL HEAD & BLOCK ON 1987-UP ENGINES |
Revised Cylinder Head & Block On
1987-Up Nissan 3.0L (VG30) Engines
Beginning with April, 1987 production, the cylinder heads and
block have been changed on Nissan 3.0L (VG30) engines.
Improvements were made to increase power output and decrease
noise levels of the engine.
Revised production engines can be identified by an engine serial
number that ends in W, such as XXXXXX W. Former engine serial
numbers end in either A or B. However, factory service
cylinder blocks will not carry the W identification even though
they feature the improvements listed below. A visual check is
necessary for proper identification.
Six new water galleries were added to the cylinder block (Figure
1) and the cylinder heads (Figure 2). This change required a
modification of the cylinder head gasket, where the original 6
water holes were downsized and 3 new holes added on the exhaust
side of the gasket (Figure 3). The revised cylinder head gasket
can also be identified by its differing identification tab.
Figure 4 best illustrates the former and revised head gaskets.
Additional changes were made throughout the engine. The pistons
now use full floating, larger diameter wrist pins. The small end
bore of the connecting rod was increased to accept the larger
wrist pin. The revised rod is also heavier than the former part.
Again, components are identified by a W stamp.
Nissan advises against the use of former parts when servicing
vehicles with engines manufactured as of April 1987. Refer to
the chart to determine the proper component combination when
servicing engines manufactured prior to April 1987 (Figure 5).
For additional information see AERA Technical Bulletins: TB 601,
653 & 752
The AERA Technical Committee
Cylinder Head Cylinder Short Acceptable
Head Gasket Block Block Combination
Revised Former Former N/A Yes
Former Former Revised N/A Yes
Former Former Former N/A Yes
Revised Revised Revised N/A Yes
Revised Former Revised N/A Yes
Revised Revised Former N/A No
Former Revised Revised N/A No
Former Revised Former N/A No
Former Former N/A Revised Yes
Revised Revised N/A Revised Yes
Revised Former N/A Revised Yes
Former Revised N/A Revised No
April 1991 - TB 761
##END## |
| REVISED CRANKSHAFT |
Revised Crankshaft On
1984-87 Nissan VG30 Engines
Nissan has revised the snout of the crankshaft and related
service parts for VG30 engines manufactured after April 1987.
Since only the revised crankshaft is being serviced by Nissan,
should it become necessary to use this crankshaft in 1984-1987
engines, several associated parts also need to be changed.
Engines manufactured prior to April 1987 carry a serial number
that ends in either 'A' or 'B'.
Component Prior to As of
Description April 1987 April 1987
Crankshaft 12201-02P80 1 12201-02P81 2
Bolt Spacer Not Required 12308-V5321
Crank Pulley Bolt Washer 12308-V5000 3 12308-77A00
12308-V5001 3
12308-V5010 3
Crank Pulley Bolt 12309-V5000 12309-16V00
1 Does not include crankshaft pulley bolt washer or
crankshaft pulley bolt.
2 Includes crankshaft bolt spacer, crankshaft pulley bolt and
crankshaft pulley bolt washer.
3 Complete application information available on parts
microfiche
The front pulley assembly is the same for either crankshaft.
The AERA Technical Committee
March 1991 - TB 752
##END## |
| REVISED TIMING COMPONENTS |
Revised Timing Components On
1988 Nissan Z24I Engines
Nissan has revised the timing components used in 1988 and later Z24I engines. The actual production change was instituted in January of 1988.
The chain assembly was updated from a single roller to a double roller type. This update requires a new crankshaft and camshaft sprocket as well as the new double roller chain. The tensioner assembly and chain guides have not been changed. Engines manufactured prior to January 1988 may be serviced with the new components as long as all three pieces are used.
The AERA Technical Committee |
| INJECTOR NOZZEL SERVICE |
Injector Nozzle Service On
Nissan SD Series Engines
Nissan has revised the lower fuel injector gasket on their SD series diesel engines.
This engine was introduced in 1981 as the SD-22 with a displacement of 2.2L. In 1984 the cylinder bore diameter was increased to bring engine displacement to 2.5L. This engine, the SD-25, was last used as part of the 1986 model year.
Nissan recommends replacement of both upper and lower fuel injector gaskets whenever the injector assembly is removed from the cylinder head. Be sure to position the lower gasket with the convex edge toward the combustion chamber (see Illustration).
The AERA Technical Committee |
| DRIVEABILITY COMPLAINTS WITH FUEL INJECTED ENGINES |
Driveability Complaints with Fuel Injected Engines
With the advances in electronic engine controls many consumer
driveability complaints have been eliminated. However, since the
introduction of port or multi-point fuel injection (MFI) systems
new complaints are being heard.
Vehicles seem to perform well for some time after they are
purchased, but as the miles mount up some of the performance and
smooth operation of the engine goes away. Since engines with MFI
are generally found in performance oriented automobiles, their
drivers will eventually notice the difference and seek out a
repair facility.
Reports from OE and other independent agencies are now detailing
that port fuel injectors are subject to residue accumulation at
the injector tip and pintle (see illustration below). These
deposits cause uneven spray patterns and incomplete atomization
of the fuel, resulting in uneven idle, poor fuel economy,
increased emissions, hard starting and loss of power.
While there are many reasons for these deposits, there are
several cures available. First and foremost is preventative
medicine. Caution your customers to purchase a high detergent,
good quality gasoline that is advertised to contain detergents.
Minor amounts of injector deposits may actually be removed with
these advanced blends.
However, there comes a time when a simple drive my engine clean
won't do the trick. The aftermarket has developed several ultra
high detergent cleaners that can be run through the fuel
injection system to clean up larger deposits and return the
injector to normal operation.
Cleaning of the injectors is accomplished by disconnecting the
normal engine fuel supply lines and disabling the fuel pump on a
fully warmed up engine. A pressure tank containing a mixture of
gasoline and 10 to 25% of cleaning detergent is connected to the
fuel rail. The vehicle is restarted and about a gallon of this
mixture is run through the injectors at above idle speeds.
Of course there are other methods that can be used to clean
injectors, the one detailed above is just one of them. Consult
OE and aftermarket service manuals for additional information.
The AERA Technical Committee
September 1988 - SB 160
##END## |
| COOLANT IN THE ENGINE OIL |
Coolant In The Engine Oil In
1989-99 Nissan 2.4L KA24 Engines
AERA members have reported engine coolant in the engine oil supply in 1989-99 Nissan 2.4L KA24 engines. Vehicle owners have expressed engine-overheating complaints and loss of engine coolant. The source of this coolant loss has not been the cylinder head, which is most often first suspected. Removal of the cylinder head may not be necessary if the information in this bulletin is first considered.
These engines use a timing chain to rotate the single or dual camshaft design used. If that chain is allowed to run loose, it may contact the front cover and wear a hole into the aluminum cover allowing coolant to enter the crankcase. To determine if this condition is present, some technicians have detected the area of leakage by attempting to pressurize the cooling system. Before any pressure builds up, an audible hissing noise has been noticed and verified with a stethoscope at the engine?s front cover.
For more information on this engine?s timing chain tensioner, see TB-1652
The AERA Technical Committee |
| ENGINE COOLANT LEAKS ON 2000-2002 NISSAN 3.3L ENGINES |
Engine Coolant Leaks On
2000-02 Nissan 3.3 VG33E Engines
The AERA Technical Committee offers the following information regarding an engine coolant leak on 2000-02 3.3 VG33E engines. Customers may complain of engine coolant under the vehicle if sitting for a period of time or the smell of coolant when the engine is warm.
A leak between the intake manifold and the water outlet housing as shown below in Figure 1 may be causing this condition. Visually inspecting this area could verify that this is the source of the leak.
To cure this problem, Nissan offers a revised fiber gasket, Part #11062-9Z000, to be installed between the water outlet and the intake manifold. When changing this gasket, make sure that you have drained the coolant just below the level of the water outlet. This will keep coolant from spilling when removing the housing.
Clean the sealing surface of the water outlet housing and the intake manifold to get rid of any old sealer that may be present. Install the two mounting bolts through the outlet housing and then slide the fiber gasket over the bolts until it is flush with the sealing surface of the housing.
Once the housing is installed onto the intake manifold, tighten the mounting bolts to a torque of 12-15 ft/lbs. Refill the cooling system and run the vehicle to verify that there are no further coolant leaks.
The AERA Technical Committee |
| HEAD BOLT CAUTION FOR 300 SERIES ENGINES |
Head Bolt Caution For
John Deere 300 Series Diesel Engines
The AERA Technical Committee offers the following information about head bolt caution for John Deere 3179, 4239, 6359, 4276 & 6414 diesel engines. These engines are referred to as the 300 series, and use two different styles of head bolts.
Flanged-head cap screws do not require washers and provide for a tighter joint between the head and block. If your engine is not equipped with flange-head cap screws, replace all cap screws. Do not intermix flanged-head cap screws and non flanged-head cap screws within a given engine. Currently, only flanged-head cap screws are used in production and provided for service.
Early production cylinder block head bolt holes were counter bored down from the deck surface .118 (3.0 mm) and use standard bolts with washers; cylinder head cap screws MUST BE tightened using the conventional method as follows;
1st step 35 ft/lbs,
2nd step 88 ft/lbs,
3rd step 110 ft/lbs,
4th step retorque cap screws after engine break-in.
Late production cylinder block head bolt holes were counter bored down from the deck surface .370 (9.5 mm) and use cylinder head cap screws with built in washers. They must be tightened using the torque turn method as follows;
1st step 75 ft/lbs
2nd step 110 ft/lbs
3rd step Wait five minutes
4th step turn each bolt an additional 50° to 70° degrees (No retorque required)
Using either style bolts requires tightening the cap screws in a spiral rotation pattern starting from the center of the head and working outward to the ends.
Important; use only clean SAE 30 engine oil and remove excess oil from cap screws, do not use multi viscosity oil to lubricate cap screws.
The AERA Technical Committe |
