Timing Belts: time limit spec

[uglyboywith11fingers]

20 or 25 years ago I had a '86 Camry, belt snapped twice on me after only 3 years/25K miles each time. No damage of course.
Currently, one daughter has a 2004 Hyundai SanteFe, only 70k miles. Last year the crank sensor failed, when mechanics were in there, they found the timing belt was missing about 25% of the teeth/ribs. Belt too loose, I don't know. Other daughter has a 2005 Kia Sorento, 130K miles, so I thought I better change the belt. Hard to tell the new belt from the old... no cracks, just a shiny surface on the back-side of the belt. Both SanteFe and Sorento had Hyundai branded belts on them. Go figure.

Pete

 

[Diamondpilot]

I'm thinking about not buying any more Toyota trucks that have a timing belt. My 2011 V8 is a chain timing gear. How do you feel about that?.

I've personally dealt with 8 broken timing chains, never a single belt. Go figure.

Chains break too.

Chris

 

[3930dave]

Having changed a good number of belts in my day and seeing a good number of cars towed into the shop with a broken belt, I would say that it really depends. Older Toyota 2.2l and 3.0l motors I would not worry about time and honestly if it were my car I would run it a lot longer than they say you should. I saw very little failure on these motors and if it does break, it does not damage the motor. Interference Hondas on the other hand I would try and change them at a reasonable interval. Time does have some effect on the belt. I believe Honda states something like if operated under 0f or above 100f use severe service witch have a shorter mileage and time requirement. There are some cars such as some Kias and Hyundias that I would change before the interval as I see the belts fail prematurely from new. I have found that how many pulleys the belt is routed between and how sharp the bends as well as belt size and material all influence life. A standard transmission will also be harder on the belt.

I knew Kia had to upgrade their Tbelt design, will have to add Hyundai to my reading list. What I recently noticed with Hyundai car engines is that they use an external water-pump, therefore not driven by the timing belt. Noted that, after seeing 2 VWs with seized water pumps - one engine was shut-down in time, one crashed hard.

On my 2000 Civic, Honda derates the belt from 168,000 km to 100,000 km for temperatures above 110F, or below -20F. (Approx. 100k miles, down to 60,000 miles). They way the manual puts it - "If you regularly drive your car....." (under those conditions above). Your call/gamble on what "regularly" is.... (Edit -> no derating for time though).

I can see really high temps drying the belt out somewhat; they definitely get harder to flex at very low temps. Interesting, your point about stick shift...... hadn't thought about a slushbox as a shock absorber in that respect.

Rgds, D.

 

[3930dave]

I've personally dealt with 8 broken timing chains, never a single belt. Go figure.

Chains break too.

Chris

You are weird...... statistically speaking that is . Can I get you to buy me a lottery ticket ?

I'm sold..... let's go for gear-drive !

Rgds, D.

 

[3930dave]

I'm thinking about not buying any more Toyota trucks that have a timing belt. My 2011 V8 is a chain timing gear. How do you feel about that?.

One reason I still have my old Volvo (red-block), is that is a non-interference 4 cylinder. Don't know of any heads designed that way, today...... but I'd like to be wrong in saying that.....

All else equal, I prefer a chain, if it is an interference engine.

Rgds, D.

 

[motownbrowne]

I sure like not having to worry about changing belt or chain in my 4.9 I6 Ford. One guy at a repair shop did try to sell me a timing belt job one time, at an estimated cost of $1000. I told him, "go right ahead, but I want to see the old belt once you take it off." Never went back to that place.

 

[Diamondpilot]

You are weird...... statistically speaking that is . Can I get you to buy me a lottery ticket ?

I'm sold..... let's go for gear-drive !

Rgds, D.

None were my actual vehicles and most were in my college days. I just helped fix them.

All were 1980's vintage trucks and 5 marine applications.

Chris

 

[aczlan]

One reason I still have my old Volvo (red-block), is that is a non-interference 4 cylinder. Don't know of any heads designed that way, today...... but I'd like to be wrong in saying that.....

Nope, that's because your B19, B20, B21, B23, B230F or B230FT is (by most standards) a low output engine and they can make a lot more HP per liter with an interference engine. Thats why the 850s, 960s, etc went with interference whiteblocks instead of continuing with the redblocks...
Thinking further, I think the B234F (DOHC redblock) was an interference engine wasnt it.

Aaron Z

 

[3930dave]

None were my actual vehicles and most were in my college days. I just helped fix them.

All were 1980's vintage trucks and 5 marine applications.

Chris

A badly designed or faulty chain can be a problem in any era. Back then, oil technology was nothing like today, so I can see some chains being an issue back-in-the-day.

Rgds, D.

 

[3930dave]

Nope, that's because your B19, B20, B21, B23, B230F or B230FT is (by most standards) a low output engine and they can make a lot more HP per liter with an interference engine. Thats why the 850s, 960s, etc went with interference whiteblocks instead of continuing with the redblocks...
Thinking further, I think the B234F (DOHC redblock) was an interference engine wasnt it.

Aaron Z

Could be on that DOHC. I never paid much attention to 'em, after the Volvo wizard I know told me to stay the _______ away from them.

Point taken, high specific hp sells.

I've always been more interested in an engine capable of running 500k km+, but am aware that is a Don't Care for most of the driving public.

If you are running up high miles, the #'s don't stack up so well on an "economy" car (or for that matter, a small displacement VW TDI) once you pay for 2 or more Timing Belt changes.

Rgds, D.