Timing belt failure log MTBF

Post by **abscate** » 01 Jun 2013, 04:24

Okay, new poll topic..

Someone here made a great point about timing belt replacement. We all live in fear of our TB going and wiping out our engines, probably more so on these older cars because it rears the ugly fix it to part it dilemma on a car we have probably nurtured into long life.....

The goal of this thread is to get > 30 logs of timing belt failures with mileage to see if we can get an idea of how long these parts last.

Entry format

First line: year, model, engine, year replaced, mileage replaced,

Second line - mechanical commentary on what failed, if anything

Post by **abscate** » 01 Jun 2013, 04:26

1999 V70 T5, 2.3l HPT, replaced belt at 135k in 2010

Belt and tensioner in good running condition at time of Replacement

Whew!

Post by **abscate** » 11 Jul 2013, 05:28

129k tensioner failure

Post by **abscate** » 11 Jul 2013, 05:29

145k TB failure, car junked

175k TB failure, car junked

97 850 GLY 170k TB

2005 S60r with 123,000 miles on it, TB broke

2001 Volvo V70 XC 2.4LT in for a fuel pump recall, and they told me the timing belt was worn and it was past due for replacement - the car is currently at 138,000 miles. The belt was due at 105,000. Hence

1999 V70 T5, 2.3l HPT, replaced belt at 135k in 2010

129k tensioner failure 1997

i have a 1995 volvo 850 wagon with 165k.

15k ago timing belt and water pump

1995, 850 t-5r, 5/2013, 207,783mi

changed the first one when I got the car at around 170,000

2001 VOLVO V70 T5, 5 SP. ( Very Rare- Fast) 200k, Mass. & VT Owners. Clean CarFax, Timing Belt Kit at 175k, Loaded, Leather, Sunroof, 2 Ft. W/B, New Tires, Excellent Condition,
A Rare Find, Well Maintained. A real "sleeper-fast". $ 6,000.

Post by **rspi** » 11 Jul 2013, 09:19

I don't quite understand what is going on here. Your first post say that you replaced the belt at 134k, then the next post states that the tensioner failed at 129k. HUH?

What's the next post about?

To be honest with you, I do not have a fear that my timing belt will fail because I replaced it when it was due. I believe these belts will last about 25% longer than the schedule when everything is replaced at the same time. Unfortunately, I don't usually change everything on my car. So, if I hear a noise, I do get a little worried but usually just tear back into it if there is a problem. Like on my 960. Changed the belt, 20k later, replaced the idler and water pump.

Just to be clear, people are breaking timing belts on all kinds of cars, newer Kia's and many more.

Post by **abscate** » 11 Jul 2013, 09:40

The goal here is to log TB failures and replacements , with a Statistical data set of 30+ to get A real MTBF. I suspect it is 150k or so

Having this number and a standard deviation will remove FUD for purchasers and buyers

Post by **Ozark Lee** » 12 Jul 2013, 01:17

Knock on wood I haven't lost one yet on the fleet but I came close. I tend to buy the sub $1,000 cars and then get them back in good working order. In that price range you typically don't get a pile of service records unless they are stuck in the glove box that broke and won't open. Even if the previous owners talk about service intervals I really don't trust them to tell me the truth any more than I believe that the odometer just broke last week.

Job one on any addition to the fleet is to change the timing belt which gives me a chance to give the rollers and tensioner a once over. From there I can at least sleep at night without worrying about whether the belt is about to break.

I did do that on my '94 and the tensioner compressed normally but a year or so later I heard what sounded like a loose belt hitting the cover and I figured it was the serpentine belt. The serpentine belt looked fine so I pulled the timing belt cover and the timing belt was very loose. The stupid plastic spacer on the tensioner saved my butt.

The car remained parked until the new belt, tensioner, water pump, and rollers came in. The timing was right on when I went to change the parts which is good, I think if it had jumped even one tooth it would have jumped many more at the same time.

...Lee

Post by **abscate** » 12 Jul 2013, 03:42

Lee..I would love to have the data on your cars...how many miles they had when they got them, since those are all TB lifetime data points

I need 30 to get a good set for analysis

Post by **rspi** » 12 Jul 2013, 08:52

I don't really understand but here are mine.

S70 GLT, At 143,000 changed everything but water pump. Now has 179,000.

My '95 850 T-5R wagon. at 205,000 changed belt and installed a used idler roller.

Post by **erikv11** » 12 Jul 2013, 09:11

I think you will find the ratio of cars without a timing belt failure, to those with one, is at least 30:1. And you can't analyze 1 failure. Wouldn't any meaningful analysis require data on hundreds of cars if you wish to consider successes as well as failures?

Do you want to know about every timing belt change on a vehicle? Just the first one? The most recent one? And you want to know about all timing parts? This gets a little complicated, you may want to set up some kind of simple row-column layout. I have good to excellent service history for five 850s (none ever had TB failure) if you let me know what you want.