Have a 2005 Toyota Sienna with 100,000 miles. Runs excellent. I just had the Timing Belt along with the Water Pump and the kit installed. At 120,000 miles I'm planning on having the spark plugs replaced. While they are doing that and the beauty cover is off, shall I also replace these following items: LOL. I'll have a mechanic do it. Replace the Spark Plug COILS, Head Gaskets, Crank Seal-Cam Seal, Coolant Plate Cover, Brake Oil Feed, and Oil Cooler line?
You are not going to replace the head gaskets as a maintenance item. When you say crank seal and cam seal, I think you actually mean a valve cover gasket. I have no idea what you mean when you say Coolant Plate Cover, Brake Oil Feed and Oil Cooler Line. I would seriously consider reading the maintenance section of your owner's manual for required maintenance items and work to be done.
Yes.
Max 120K
120,000 miles or 144 months (12 yrs)....you're ok on the miles, but past the time. If it's running ok, just change them when you get close to hitting the 120k mile mark. Good luck with the back 3.
Page 19 of the warranty and maintenance guide.
https://www.toyota.com/owners/resources/warranty-owners-manuals.sienna.2005
LOL. I'll have a mechanic do it. Might as well change the coils too? Right? Maybe at that mileage how about the Head Gaskets, Crank Seal-Cam Seal, Coolant Plate Cover, Brake Oil Feed, and Oil Cooler line?
Shall I change the Alternator as a preventive maintenance
no. It is not a maintenance item.
Maintenance should be listed in your owner's manual
Have a 2005 Toyota Sienna with 100,000 miles. Runs great and I just just replaced the starter because it went bad. I did the Timing and water pump. The Alternator works fine but since it's 17 years old and I bought this car to do a-lot of stop and go local driving and 1 far trip to the big city every Saturday. (70 mile round trip) Shall I change the Alternator as a preventive maintenance issue or just leave it until it's no good and the car shuts off?
Put a meter on your battery with the car idling - it should be showing about 14.5 volts. If it's significantly lower, you need a new alternator.
Oh my reading is fine. I'm just wondering because it's 17 years old, if one day soon will it conk-out? LOL.
Bought a 2005 Toyota Sienna with 100,000 miles in great shape with no past service records. Runs great. Should I change my PCV Valve? Should it be changed every 100,000 miles or don't fix it if it isn't broke?
Should I change my PCV Valve?
Yes, replace it every few oil changes.