| TIMING CHAIN INSTALLATION ON 79-85 MAZDA 2.0L |
Timing Chain Installation On
1979-85 Mazda 2.0L Engines
Correct installation of the timing chain on 1979-85 Mazda 2.0L
engines is critical to achieve the proper valve timing.
Rather than aligning the camshaft and crankshaft gears with marks
on the cylinder head or block, this engine uses marked plates on
the timing chain to set valve timing.
Start the timing process by rotating the crankshaft and camshaft
sprockets until the keyways are facing straight up (12 o'clock).
This should face the camshaft sprocket timing mark at 3 o'clock
and the crankshaft sprocket timing mark at approximately 5
o'clock looking at the front of the engine.
Locate the three marked links on the timing chain. Two links
should be positioned at the crankshaft sprocket so that the
timing mark is between the links (Figure 1). Position the chain
and camshaft sprocket so that the mark is in the middle of the
other marked link (Figure 2). There should be 20 unmarked plates
between the two positions.
Be careful, some timing chains do not use marked plates to
indicate the correct timing positions for the camshaft and
crankshaft. Use the old chain as a guide to make your own marks
on the new chain.
The AERA Technical Committee
August 1991 - TB 796
##END## |
| VALVE TRAIN NOISE ON MAZDA 2.0L ENGINES |
Valve Train Noise On
1993-94 Mazda 2.0L Engines
The AERA Technical Committee offers the following information regarding a valve train noise on 1993-94 Mazda 2.0L engines. This noise can be associated with the Hydraulic Lash Adjusters (HLA).
This noise appears after the engine has been run at idle for a long period of time. The noise appears because air is entering the oil gallery. To prevent this condition from happening, Mazda had redesigned the oil pump plunger as shown in Figure 1.
HLA noise will appear at the top of the engine and is several times faster than that of the engine speed. Verify the complaint by running the engine at idle for a period of time not letting the vehicle overheat. If the HLA noise is present, replacement of the oil pump plunger is required.
To replace the oil pump plunger, remove the snap ring at the bottom of the pump as shown in Figure 1. Remove spring seat, pressure spring and the plunger. Replace the old plunger with the new plunger, Part #JF01 14 115. Reassemble the bottom of the oil pump in the reverse procedure of disassembly
NOTE: Follow instructions in the service manual for disassembly and assembly of the engine to get access to the oil pump for replacement of the plunger.
The AERA Technical Committee |
| COOLANT IN THE OIL |
Coolant In The Oil On
Mazda 1.5 & 1.6L Engines
AERA member machine shops should carefully inspect the cylinder head when resolving engine oil contamination complaints.
The cylinder head carries two cup type freeze plugs on the valve spring side of the cylinder head. Leaking freeze plugs will accumulate a black residue during operations. Pressure testing the cylinder head confirms that the plug or plugs were leaking.
Successful repairs include replacement of the plug or peening the metal surrounding the plug over it. Be sure to re-pressure test the cylinder head after repairs are completed.
The AERA Technical Committee |
| REVISED CYLINDER HEAD BOLT |
Revised Cylinder Bolt For
1995 Mazda 2.5L, KL Engines
The AERA Technical Committee offers the following information on a revised cylinder head bolt for 1995 Mazda 2.5L KL engines. The cylinder head bolt length was reduced and the accompanying washer eliminated beginning with vehicle VIN Code 1YVGEDS5361783 and engine serial number KL556012.
Using the short bolt with an additional washer may result in an improper clamping load. The original design bolt (longer) may be used on engines produced after the serial number break ONLY if the washer is installed. The current head bolt (shorter) may be used on the engines produced before the serial number break ONLY if the washer is eliminated.
The torque values used to install the cylinder head bolts remains as previously published. Mazda allows reuse of bolts in good condition if their lengths do not exceed 5.315 (135mm) for the shorter bolts or 5.127 (132.5 mm) for longer bolts. Follow the steps listed below to tighten the cylinder head bolts for this engine.
Step 1. Torque all bolts in sequence to 17-19 ft/lbs.
Step 2. Paint on all bolts and head casting to help indicate their position.
Step 3. Rotate all bolts in sequence an additional 85-95° (Figure 2 & 3).
Step 4. Rotate all bolts in sequence an additional 85-95° (Figure 2 & 3).
The AREA Technical Committee |
| CAMSHAFT INSTALLATION ON 1995-2002 MAZDA 2.3L KJ ENGINES |
Camshaft Installation On
1995-2002 Mazda 2.3L KJ Engines
The AERA Technical Committee offers the following information regarding camshaft installation on 1995-2003 Mazda 2.3L KJ engines. If the camshafts are not installed correctly, engine damage may result.
When reinstalling the camshafts during engine installation, the original timing marks may have been worn away over time. If this is the case, mark and install the intake and exhaust camshafts using the procedure described below.
NOTE: The procedure for the left and right cylinder banks is different. Be sure to follow each procedure correctly.
Right Bank Cylinder Head (Figure 1)
Intake Camshaft Indexing: From the backside of the intake camshaft timing gear, locate the small stamped dot. Gear may need to be cleaned to locate the dot. Start with the tooth with the dot and count clockwise 31 teeth. Mark the 31st tooth with a scribe mark.
Exhaust Camshaft Indexing: From the backside of the exhaust camshaft timing gear, locate the small stamped dot. Gear may need to be cleaned to locate the dot. Start with the valley stamped with the dot and count clockwise 4 valleys. Mark the 4th valley with a scribe mark.
Installing Camshafts: Align the marked intake gear tooth with the marked exhaust gear valley. Install the camshafts into the cylinder head. Verify the alignment of the scribed marks.
Left Bank Cylinder Head (Figure 2)
Intake Camshaft Indexing: From the backside of the intake camshaft timing gear, locate the small stamped dot. Gear may need to be cleaned to locate the dot. Start with the tooth with the dot and count clockwise 1 tooth. Mark the 1st tooth with a scribe mark.
Exhaust Camshaft Indexing: From the backside of the exhaust camshaft timing gear, locate the small stamped dot. Gear may need to be cleaned to locate the dot. Mark the valley with a scribe mark.
Installing Camshafts: Align the marked intake gear tooth with the marked exhaust gear valley. Install the camshafts into the cylinder head. Verify the alignment of the scribed marks.
The AERA Technical Committee |
| LARGER CRANKSHAFT JOURNAL DIAMETER FOR 1.8L KIA ENGINES |
Larger Crankshaft Journal Diameter for
1995-2002 Kia 1.8L VIN 5 Engines
The AERA Technical Committee offers the following information on a larger crankshaft journal for 1995-2002 Kia 1.8L VIN 5 engines. The main journal diameter for the crankshaft of this engine increased in diameter beginning with the 1998 model year. Mazda manufactured engines used prior to 1998 and Kia manufactured subsequent engines.
Caution should be used when ordering replacement parts including crankshafts and main bearing sets as aftermarket catalogs may not reflect two different part numbers for the different years.
Application Main Journal Diameter Rod Journal Diameter Stroke
1994-97 1.9661-1.9668 1.7693-1.7699 3.346 (49.939-49.957 mm) (44.94-44.955 mm) (85 mm)
Main set 0K2YA11SG0
1998-02 2.1629-2.1636 1.7693-1.7699 3.430
(54.938 - 54.956 mm) (44.94-44.955 mm) (87 mm)
Main set 0K2Y211SG0
Kia indicates connecting rod and main bearings are available in standard, .010 (.25 mm), .020 (.050 mm) & .030 (.75 mm) undersizes. Reference to the sizes listed in the Kia service manual should not be used for grinding, as they?re incorrect.
The AERA Technical Committee |
| REVISED ROCKER ARM FOR 3.0L SOHC MAZDA |
Revised Rocker Arm For
1989-96 Mazda 3.0L SOHC Engines
The AERA Technical Committee offers the following information regarding a revised rocker arm for 1989-96 Mazda 3.0L SOHC engines. This revision came as the result of customer complaints of upper engine noises. This information should be considered anytime rocker arm service is performed.
To reduce the likelihood of hydraulic lash adjustor (HLA) noise and provide a more durable lifter the depth of the HLA locating hole has been reduced as shown in Figure 1.
To help distinguish this revised rocker arm it is identified by a projection on the camshaft end of the rocker as shown in Figure 2. The original rockers shown in Figure 3 do not have a projection in that location.
To allow salvage operation of original style rockers for those engines that have exhibited noise complaints a ?washer" is available to insert under the HLA as shown in Figure 3. The ?washers" are available with Part #JEY1-12-SHO and are packaged 18 per part number. Rocker arm shafts and rockers for intake and exhaust sides are unique to their location. The revised style rockers and shaft can be used in place of the original style components, but not the other way around.
Revised Part # Old Part # Description Quantity
JFO1-12-160D JFO1-12-160C Intake Rocker Arm Shaft 2
JFO1-12-170E JFO1-12-170D Exhaust Rocker Arm Shaft 2
JFO1-12-130E JFO1-12-130D Intake Rocker Arm 12
JFO1-12-150D JFO1-12-150C Exhaust Rocker Arm 6
JEY1-12-SHO NONE Adjustment Washer 18
The AERA Technical Committee |
| MEASURING CYLINDER HEAD THICKNESS |
Measuring Cylinder Head Thickness On
1995-99 Mazda 2.3L KJ Engines
The AERA Technical Committee offers the following information on measuring cylinder head thickness on 1995-99 Mazda 2.3L KJ engines. Since the valve cover rail on this cylinder head is on an angle, measurements from the deck of the head to the valve cover rail would be inaccurate.
To correctly measure the cylinder head thickness on this head, Mazda offers two measurement areas and thickness to use. Measurement A and B, as shown in the figure below, are measured from the deck of the cylinder head to the center line of the cam housing bores of the head. Measurement A should be 5.744-5.748 (145.89-145.99 mm), while measurement B should be 5.032-5.036 (127.81-127.91 mm).
Mazda indicates this head should be resurfaced if warpage exceeds .004 (.10 mm). Mazda does not supply a minimum head thickness for this cylinder head,
however, AERA members report successfully removing .010 (.254 mm).
The AERA Technical Committee |
| OIL CONSUMPTION ON 1989-94 3.0L VIN JE |
Oil Consumption On
1989-94 Mazda 3.0L VIN JE Engines
The AERA Technical Committee offers the following information on oil consumption on 1989-94 Mazda 3.0L VIN JE engines. The area of concern causing this oil consumption is the cylinder head. At this time, only the single
overhead cam (SOHC) heads have been affected. It appears this cylinder head is prone to cracking on the valve spring side of the head as mentioned in AERA Technical Bulletin TB-1260.
In at least some of the instances reported a dissimilar crack as described in TB 1260 has been observed. These cracks have allowed oil to enter the combustion process around either valve guide. These cracks create a passage
for hot engine oil to seep through the openings or voids created. Engine oil collects in this area of the head, allowing ample amounts of oil to pass. There have been reports of one quart of oil consumed in 50 miles driven.
The extent of these cracks in most instances has been too excessive to warrant successful welding repairs as some have been reported to be longer than 6 inches. In other instances where the cracks have not been so severe but
leakage was detected, welding has provided a successful repair.
The AERA Technical Committee |
| ENGINE OVER COOLING |
Engine Over Cooling
On 1994-97 Mazda 2.3L VIN A Engines
The AERA Technical Committee offers the following information on engine over cooling on 1994-97 Mazda 2.3L VIN A engines. Some customers have complained there is insufficient heat coming from the heater in the cab of the vehicle.
One cause of this type of condition may be a casting slag from the cylinder head that has become lodged in the thermostat housing. When this occurs, the
thermostat is unable to close completely. That opening allows the engine to over cool or never warm up to the correct operating temperature. To repair this problem, flush the entire cooling system (engine and radiator) to remove any slag that could be left in the engine.
To cure this problem at the factory, Mazda revised the cylinder head casting process during the 1997 model year.
The AERA Technical Committee |
