Service Schedule on Serpentine Belt

[Aaron]

I have read the "STICKY" What services you need and what you don't, but I couldn't find anything about the belt. What is the service schedule on the belt? I know the timing chain is nothing to worry about.

What about hoses, etc?

Also, I read something about Valve Clearance??

[Patrick Wong]

Originally Posted by Aaron

I have read the "STICKY" What services you need and what you don't, but I couldn't find anything about the belt. What is the service schedule on the belt? I know the timing chain is nothing to worry about.

What about hoses, etc?

Also, I read something about Valve Clearance??

Hi Aaron,

I suggest you either refer to the warranty/maintenance book or else the Toyota website. For example, following is the 2004 schedule for 60K miles:
Toyota Parts and Service

Regarding the serpentine drive belt, the schedule suggests the initial inspection at 60K miles/72 months; then inspections every 15K miles/18 months thereafter.

I replaced the belt on my 2001 at ~60K miles because the outside surface was getting glossy. That belt had to turn the AC compressor pulley as well as the engine coolant pump.

Since the 2G belt only has to turn the engine coolant pump, it has a much easier life. However it is not expensive and is easy to replace, since the tension on the idler pulley can be easily adjusted. I will probably replace the belt on my 2004 (now at 48K miles) at 75K miles just for fun, not because it actually needs changing.

Regarding the engine coolant hoses, since the Prius gasoline engine doesn't generate much excess heat the hoses are on light duty. Unless you see a leak, I think they will be good for easily 100K miles.

Regarding valve clearance adjustment, I did that on my 2001 at 60K miles and found that a few valves were slightly loose. However I decided to leave well enough alone since adjustment requires removing the camshafts and replacing the valve bucket spacers.

I believe that the recommended valve inspection is just to listen for excess noise, unless there is a driveability problem. It seems that the normal wear pattern is towards excessive valve clearance rather than insufficient valve clearance.

[edthefox5]

Originally Posted by Patrick Wong

Hi Aaron,

I suggest you either refer to the warranty/maintenance book or else the Toyota website. For example, following is the 2004 schedule for 60K miles:
Toyota Parts and Service

Regarding the serpentine drive belt, the schedule suggests the initial inspection at 60K miles/72 months; then inspections every 15K miles/18 months thereafter.

I replaced the belt on my 2001 at ~60K miles because the outside surface was getting glossy. That belt had to turn the AC compressor pulley as well as the engine coolant pump.

Since the 2G belt only has to turn the engine coolant pump, it has a much easier life. However it is not expensive and is easy to replace, since the tension on the idler pulley can be easily adjusted. I will probably replace the belt on my 2004 (now at 48K miles) at 75K miles just for fun, not because it actually needs changing.

Regarding the engine coolant hoses, since the Prius gasoline engine doesn't generate much excess heat the hoses are on light duty. Unless you see a leak, I think they will be good for easily 100K miles.

Regarding valve clearance adjustment, I did that on my 2001 at 60K miles and found that a few valves were slightly loose. However I decided to leave well enough alone since adjustment requires removing the camshafts and replacing the valve bucket spacers.

I believe that the recommended valve inspection is just to listen for excess noise, unless there is a driveability problem. It seems that the normal wear pattern is towards excessive valve clearance rather than insufficient valve clearance.

Ahh..lovely pictures of a super clean top end...a motor that has spent its life on Mobil One I suspect!

[Aaron]

Very beautiful indeed.

[Patrick Wong]

Originally Posted by edthefox5

Ahh..lovely pictures of a super clean top end...a motor that has spent its life on Mobil One I suspect!

Hi Ed,

Thanks, but sorry to disappoint: I use Castrol GTX 5W-30 mineral oil along with the Toyota-branded oil filter, and observe 5K mile changes.

[N3FOL]

Does my '08 have a auto belt tensioner pulley for the serpentine?

[Patrick Wong]

Originally Posted by N3FOL

Does my '08 have a auto belt tensioner pulley for the serpentine?

I do not believe that the belt tensioner design changed within 2G model years. My 2004's tensioner pulley is not spring-loaded.

The adjustment procedure is to loosen the nut on the pulley, then turn the adjusting bolt to achieve the desired belt tension. Tightening torque on the pulley nut is 30 ft-lb.

The desired belt tension is reached by pressing in the middle of the belt's longest run with 22 lbs pressure, deflection of a new belt should be between 0.35 to 0.47 inches. A used belt should show deflection from 0.43 to 0.59 inches.

A new belt is defined as a belt that has been in service less than 5 minutes.

[hobbit]

If you're going to go in there and muck with the tensioner at
all, I'd take the whole assembly apart and clean it off and put
some anti-seize on the various threads. You can check the idler
bearing at the same time. That's the piece that's going to
accumulate the most revolutions over time, in fact, since all
the other pulleys are bigger.
.
_H*

[patsparks]

During servicing checking the belt tension and wear is normal. Look for tiny cracks on the ribs inside the belt. If you see any cracks replace the belt. It is unusual to need to adjust the tension on this type of belt for the life of the belt. Check the idler pulley bearing every time you change the belt, maybe every 100,000 miles or more. I have used after market belts in the past but when I last changed the belts on my Camry I used genuine Toyota belts, all the squeaks and noises from the belts went away. From then on I only use Toyota belts.

[galaxee]

pat, there's a reason oem is worth the money. we rarely if ever use aftermarket parts on our cars and the cars we flip.