AfterMarketNews Brake&Frontend BodyShopBusiness Counterman EngineBuilder Fleet Equipment ImportCar Motorcycle & Powersports News Servicio Automotriz Shop Owner Tire Review Tech Shop Tomorrow's Tech Underhood Service Speedville

Preventive Maintenance Profits: Preferred Automotive, Jenkintown, PA

With the summer months heating up and cross-country road trips beginning, many people want to make sure their vehicles are prepped for the long haul. For the first-ever July edition of Maintenance Chronicles, we will focus on Preferred Automotive Specialists,...

Read more...

GM HVAC Door Actuator Motors: Operation And Calibration

GM Electrically Driven Actuator Motors Long gone are the cables and rods jutting out of the firewall to operate the heater control valve or a vacuum unit pulling a blend door open. These days, it’s electrically driven actuator motors (modules) accomplishing...

Read more...

Solving Carbon Deposits In Direct Fuel Injection Engines

Symptom: Misfire codes, stumbling and suspicious fuel trim numbers. On a scan tool, the engine may show a loss in volumetric efficiency. The driver may complain about a loss of power, poor fuel economy and hard starts. Cause: Carbon deposits on...

Read more...

Making Sense Of Steering Angle Sensor Input And Data

Measuring the­ ­position angle, rate of turn and force of the steering wheel is critical for Electronic Stability Control (ESC) systems. Scan tools call these Steering Angle Sensors (SAS) and typically display the information in degrees. The SAS...

Read more...

Rotor Failure: Why Rotors Crack And Make Noise

The prices of rotors seem to be dropping the past few years. Call just about any parts supplier and they can quote you a vast range of prices for the same application. And when you compare the rotors side-by-side, they may look the same, but the difference...

Read more...

Tire Tread Wear: Causes And Symptoms

Understanding Tire Tread Wear Tire tread wear can tell you a lot about a suspension. Most specifically, it can tell you if the angles, inflation and components are within specification. Here are the most common tread wear patterns and what causes them. Over-inflated...

Read more...

The Ins And Outs Of Sanders

Sanders are required tools in today’s collision repair shop. Body techs and painters rely upon them every day to achieve that perfect finish on your customers’ vehicles. Whether you’re prepping a panel for paint or removing imperfections before...

Read more...

Are You Regularly Maintaining Your Equipment?

Technicians who are idling because the welder won’t feed wire, the hydraulic ram won’t pull chains, the booth heater won’t heat or the air compressor won’t compress enough air is a costly mistake, as labor time is the most expensive thing in any...

Read more...

Celebrate 'Back To The Future' Day By Watching The Time Machine Get A 2015 Detail

    For many today is just another Wednesday, but for a lot of people it is more than just your average Wednesday, it is "Back to the Future" Day. It is a day that everyone who watched the cult classic trilogy Back to the Future recognizes...

Read more...


Home Asian Engine Maintenance: Timing Belt Replacement on Lexus GS 300s

Print Print Email Email

When I think of a “sports sedan” I usually think of the German variety. A BMW 3 or 5 Series, or maybe an Audi Quattro or “E” series Mercedes. Since the early 1990s there has been another choice, but the sales figures have kind of kept these cars a secret. The cars I’m talking about are in the Lexus line of upscale luxury cars, but are either sold as an entry-level car above the ES (fancy Camry), or a step below the flagship LS Series.

The GS and more recently the IS platforms are high-quality, performance luxury models with a conventional front engine, rear-drive or all-wheel-drive layout. Initially, these cars were powered by an in-line six-cylinder from the Toyota Supra line. Later models have gone to V6 and V8 powerplants. Since these cars are somewhat rare (you have to look to spot one on the road), many people would mistake them for their luxury “fluff mobile” cousins in the LS class.

The focus of this article will be the timing belt replacement on a 2001 Lexus GS 300 with the in-line six-cylinder 2JZ-GE engine with VVT-i (Toyota’s variable valve timing). Nothing can spoil the resale value of a high-dollar car more than an engine failure. Due to the complexities of the valve timing and internal engine clearances, these engines will most likely bend valves if the belt fails, or if the belt is installed incorrectly. For these reasons, I would recommend that you read through this article and the service manual description for this job very carefully before starting this repair. There are also differences between models on this platform that can impact the way certain components are removed.

WHEN TO REPLACE
Recommended replacement intervals for timing belts are all over the map these days. Depending on which tech manual or tech assistance site you access, you can get widely varying mileage and time suggestions.

photo 1: it’s difficult to see the dohc in-line 6-cylinder under all of the plastic covers.My advice is to look closely at the accessory belts, note any cracking or evidence of replacement, and then factor in the use of the car and its maintenance history. Cars that are driven primarily in hot, dry climates will probably benefit from earlier replacement than those living in more moderate conditions.

Due to the possibility of engine damage if the belt breaks or jumps time, I would not recommend waiting beyond six years or 90,000 miles, which is the OE-recommended interval for this engine.

A quick scan through service bulletins, tech assistance requests and first-hand experience with this repair leads me to advise that extra care be taken on this repair. Ensure that every step is done correctly, and the proper tools and procedures are used to prevent comebacks, driveability complaints or difficulties in completing this service.

FIRST STEPS
photo 2: color-coding the timing marks will help avoid confusion.Because of the interference possibilities, I suggest removing the ignition key and hiding it so the engine does not get cranked by mistake while the belt is off. The job is easier if it is on a hoist and the lower engine covers are removed. Drain the coolant and remove the fan shrouds.

The various models and yearly changes to this series of cars make an initial inspection worthwhile after checking a repair information source. To prevent the possibility of damage, I would recommend removing the radiator and fan just to provide more working space (see Photo 1). Without removal of the radiator and shroud, space to remove the crankshaft pulley bolt is pretty much non-existent. (On SC 300 models, the battery and battery box will also need to be removed.)

The serpentine belt tensioner may turn either direction depending on model, and the pulley mounting bolt will have threads of one direction or the other, depending on the adjusting rotation of the tensioner. Remove or loosen the brackets for the external accessories (alternator, power steering pump and A/C compressor) as needed to allow removal of the lower front engine cover. Depending on the year, model and body type, some accessories and their brackets are removed or can be left in place to save repair time.

The two upper timing belt covers can now be removed to allow the setting up of the engine for disassembly. Toyota designates these covers as cover 3 (the large piece with VVT-i on it) which looks like the front of a large valve cover, and cover 2, the center part of the front engine cover. If you haven’t already done so, remove the serpentine belt tensioner. Using a suitable tool to hold the crankshaft damper, loosen but don’t remove, the bolt and pulley at this time.

ENGINE SETUP
photo 3: the location of timing marks on the vvt-i sprocket.In order to get the engine in the correct position for removing the timing belt, the tension on the variable timing must be removed to allow the engine to be at actual TDC.

Turn the crankshaft clockwise to align the main timing mark (see Photo 2) on the damper with the “O” mark on the number 1 timing cover (lower part of front cover). There are two marks on the crankshaft pulley and two marks on each of the camshaft sprockets. The main crankshaft timing mark is 60 degrees counterclockwise from the sub-timing mark. The main camshaft timing marks are 30 degrees counterclockwise from the sub-timing marks.

photos 4a & 4b: marks on timing cover 4 (inner timing cover) are difficult to make out without highlighting.Note the location of the camshaft timing marks at this point. On this engine, I recommend that the marks be painted (preferably with different paint colors) to more easily reference the proper marks and locations (see Photo 3), with the hard-to-see marks on the number 4 timing cover (inner timing belt cover, see Photos 4a and 4b). Obviously, if the camshaft marks are not anywhere close, turn the engine another revolution clockwise and start the alignment process again.

Pages: 1 2Next page

The following two tabs change content below.
Latest articles from our other sites:

Honda TPMS Service

Honda TPMS can be one of the more difficult systems to program in new sensors, relearns and calibrations. But once you know the basics, it is easy to service these vehicles. Honda direct TPMS are different...More

Subaru Pulse-Width Modulated Fuel Pumps

I think it might have been a 2003 Subaru WRX, but it was parked in front of my local Subaru specialist’s shop after going on its fourth fuel pump replacement from other shops in less than six months....More

Solving Brake Noise With the Right Brake Pad and Shim

Where does brake noise originate from? When a brake pad makes contact with the rotor, it causes the brake pad and rotor to vibrate. This is “ground zero” for all brake noise. If the vibration is transmitted...More

Cleaning Disc Pad and Brake Shoe Break-In (Burnish) Procedure

An effective burnish cycle to seat the friction materials into the opposing rotor and drum surfaces requires approximately 200 stops. The 200 stops are consistent with the burnish procedure outlined in...More

Handheld Digital Tire Inflator from AME International

AME International announces the release of its Accu-Flate XL, a handheld digital tire inflator. The Accu-Flate XL measures, inflates and deflates tires with advanced precision and is for use in the...More

AIRCAT Composite Stubby Impact Wrenches

AIRCAT Pneumatic Tools, a division of Florida Pneumatic Manufacturing Corporation, announces the launch of its new composite versions of its Stubby impacts – the 1056-XL and 1076-XL 3/8”. With 550...More