timing belt replacement

lucas1lucas1 Member Posts: 2
edited March 2014 in INFINITI
Is it a coincidence or have dealers found a new way to rake in some repair/maintenance money? Within a two-week period my '93 lexus sc300 and my '97 Infinity QX4 had recommendations for me to replace my timing belt in order to avoid a future disaster. I've experience no problems and they have offered no test results to indicate any particular problem--both are very low mileage vehicles.


  • swschradswschrad Member Posts: 2,171
    if not, and you don't have evidence of oil leakage, follow the manual.

    in generic observation, while not all engines with timing belts have interference engines (meaning high-efficiencies that can only be met with parts that will collide inside the cylinders if the belt breaks or jumps a cog, typically ruining the head, the engine, or both), AFAIK /no/ interference engines use timing chains.

    without specific information telling you your engine is or is not an interference engine (gates rubber has a good catalog at or near


    if timing belt for your car has an asterisk, it is an interference engine,) assume the worst.

  • fleetwoodsimcafleetwoodsimca Member Posts: 1,518
    None of the intake valves can be fully open when the piston reaches the top of its travel in the cylinder. The only time that could happen would be when the timing belt is not functioning properly. The piston and the valve(s) interfere with one another, and disaster occurs when they collide. In a noninterference engine, the valves cannot be bumped by pistons, even when the timing belt is not functioning properly. That is, there is more than enough clearance for the valve(s) to be open at the time the piston reaches the top of its movement in the cylinder.
  • lucas1lucas1 Member Posts: 2
    Not a recall--just a letter from two different dealers in bold print.
  • swschradswschrad Member Posts: 2,171

    that's just what the dealer letters were.

    read your automaker's owner's manual, follow the guidelines in there on when to have the belt replaced unless you have evidence of oil or other issues, or somebody gives a recall notice or a TSB and meets you at least partway on the price of the replacement.

    and don't forget to have the turn signal lights rotated.
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    If your manual says to replace the belt, do it + or - 10% of mileage suggested.
  • nippononlynippononly SF Bay AreaMember Posts: 12,555
    That was good - rotation of turn signals - gotta keep those bulbs fresh! $99.95 please!

    Dealers will tell you all kinds of stuff to get money out of you - even selling you maintenance that is not in the maintanance schedule for the vehicle, and not needed. It can be very irritating, and can make you poor quickly if you go for it!

    2014 Mini Cooper (stick shift of course), 2016 Camry hybrid, 2009 Outback Sport 5-spd (keeping the stick alive)

  • gekko2gekko2 Member Posts: 87
    I have posted this elsewhere - but does this look good to everybody? Comments?


    Every 3,750 Miles:
    Oil and Oil Filter Change

    Every 30,000 Miles:
    Radiator Coolant Flush/Change
    Air Filter Change
    BG MOA Oil Additive
    BG 44K Fuel Induction Additive

    Every 60,000 Miles:
    Transmission Fluid Flush/Change
    Spark Plugs Change/Tune-Up
    Brake Fluid Flush/Change
    Power Steering Fluid Flush/Change
    Battery Check/Change

    Every 90,000 Miles:
    Timing Belt Change

    Every 1 Year:
    Exterior Wax/Detail
    Interior Leather/Wood Cleaning and Conditioning/Detail and Carpet Shampoo
    Wiper Blade Inserts Change
  • 8u6hfd8u6hfd Member Posts: 1,391
    The SC300 has an interference engine. Timing belt snaps, and kiss the valvetrain and maybe the pistons goodbye.

    Co-worker just had that happen...$3500 in repairs, versus about half as much if he done 3 timing belt changes in 180,000 miles.
  • fleetwoodsimcafleetwoodsimca Member Posts: 1,518
    I presume the owner of the 180K vehicle will get rid of it rather than have it repaired. It is still a win situation giving it up, I would think.
  • 8u6hfd8u6hfd Member Posts: 1,391
    He's getting it repaired...it's stuck in Maryland and he's up here in NE PA/ North Jersey
  • nippononlynippononly SF Bay AreaMember Posts: 12,555
    car that will run forever if he fixes it - great engines and transmissions, as long as it has no rust, it should go 300K. Gotta change those timing belts tho!

    2014 Mini Cooper (stick shift of course), 2016 Camry hybrid, 2009 Outback Sport 5-spd (keeping the stick alive)

  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    Your maintenance plan looks great. The only thing I'd personally change is:

    I'd bump the brake fluid change to 30K, not 60K

    I'd change out the air filter more frequently

    I'd change all the belts and hoses (after inspection of course) as needed.

    I'd swap out the water pump along with the timing belt if it's right there staring at you during the timing belt change.
  • gekko2gekko2 Member Posts: 87
    1. What's the downside of brake fluid change at 60K vs. 30K? Is possible corrosion from moisture the problem?

    2. When would you do air filter? 15K?

    3. Belts and hoses - I am assuming my mechanic checks these as needed.

    4. I got the timing belt done at Lexus and forgot to ask them to do the water pump. I never did ask them if they did it but I assume they inspected it and it was OK. ???

    (I do about 20,000 miles per year so a few of my items may be different for me than for someone who does less - since my mileage points will come almost twice as fast)
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    Well if somebody really got in there and squeezed the hoses and really looked the belts over (I don't mean tug on them) then okay. Brake fluid is meant to absorb water and it gets cruddy and sometimes can even boil. 60K is too long I think.

    As for the water pump, you can check it for excessive play but on many cars it is so easy to replace after the timing belt shrouds, belts, hoses, etc. have been removed. You'll feel bad if it goes next year and you have to rip everything out again and pay double labor. Doing the pump with the belt, on many cars (not all) might only add .5 or 1.0 hours labor.
  • erk5erk5 Member Posts: 21
    noticed that ride quality has worsen. Any of you with a '97 replace shocks and/or struts? How much did it cost? Did you go with OEM or aftermarket? And should I go through Infiniti or an auto shop?

    I'm afraid of choosing the wrong shocks. I would like the original ride quality back. And should I replace everything (springs, bearings, mounts)?

    I was looking at previous posts, and noticed a service bulletin for the rear shocks only on 97s. It says that the rear bottoms out over bumps. Anyone know about this? Will they replace it for free?
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