Don't change your timing belt

[the caveman]

Found this in a 1979 Road & Track tech article:

[burn_your_money]

I gotcha covered Marc.

I wonder how long his "lifetime" timing belt ended up lasting...

[TylerDurden]

Generally, they last the lifetime of the engine.

[libbydiesel]

That's a lot like the 'lifetime automatic transmission fluid' and the 'lifetime coolant' in the vanagon.  I'm pretty sure 'lifetime' is considered the warranty period and that causing the engine or trans to fail immediately after the warranty period is good for parts sales. 

[745 turbogreasel]

^ so 40,000 miles.

[the caveman]

Back at the dealer we used to  change the diesel belts at 160,000 k (100,000 miles for 'mercans). The gassers would be changed when they showed wear or cracks. We only started to look into it when the B2 16V Passats started breaking belts as early as 40,000 k. This was back in about 1991. We weren't a very big dealer but never had an issue with a diesel motor damage from a late belt change

[the caveman]

Oh as far as timing chains are concerned, if any of you know about the 2.0 liter turbo  TSI and FSI gasser engines; besides the problems we are having with the timing chain bridge oil screen breaking and going into the spool and intake cam, we are now seeing the cam chains stretching at about 100,000 k on some. We have 3 in the shop this week with bent valves, etc. Mostly on Tiguans with poor (or actually even with the 15,000 k oil changes) maintenance. That and the balance shaft bearings seizing! Lots of work for us, but does not bode well for customers who are out of warranty

[the caveman]

"the only type that seems to be service free are gear driven types. " Were the GM engines with the plastic timing gears have a service interval? Saw a couple of destroyed motors with those stupid parts

[libbydiesel]

I'm not up on GM engines, but the 'plastic timing gears' I've seen were nylon coated, not completely made of plastic.  Still very stupid from a longevity standpoint but the quiet the valve train some and help sell the crap cars when 'the engine sounds so quiet'...

I have an actual 1979 Mk1 Bentley (not a reprint) and it says, I quote, "You do not need to replace the camshaft drive belt unless inspection shows it to be faulty."

[RabbitJockey]

the belts hold up much better than you'd think, i had a 1990 cabriolet 1.8l engine, 170k the belt must have been original, the tensioner actually locked up and the belt was so glazed over it just slipped over the tensioner as if it were supposed to be locked up, i didn't even notice until it started to squeak a little haha.

[745 turbogreasel]

I'm not up on GM engines, but the 'plastic timing gears' I've seen were nylon coated, not completely made of plastic.  Still very stupid from a longevity standpoint but the quiet the valve train some and help sell the crap cars when 'the engine sounds so quiet'...

I replaced a few of those on  GM and Mopar.  Never hurt anything but the $30 chain and gear.
Mostly on original unopened engines with 200K & 20 years on them.
Also, it was easy to  check  for  the chain getting loose anytime the distributor  cap was off, so it never happened to any of mine.

[clbanman]

Had a Jeep Cherokee Golden Eagle with the 360 that had the plastic teeth on the large timing gear.  Solid nylon, not just a coating over metal teeth.  Quiet right until the chain slipped over 2 teeth and it wouldn't start.  Didn't do any damage to the engine. 

[vanbcguy]

The AHU I bought for my swap had the worst t-belt I've ever seen.  The whole inside of the cover was filled with timing belt fuzz, the belt was about 1/8" narrower than it was supposed to be and there was so much rubber worn off the top you could see the teeth through the 'flat' side of the belt.  Had she not crashed the car it probably would have broken the belt in a few thousand km....

[libbydiesel]

A couple years back I was visiting a friend's shop when a fellow on a cross-country trip in an '82 diesel vanagon stopped in to buy some biodiesel from my friend.  I took a look at his engine and saw a bunch of kevlar dust.  This was his timing belt...



Total remaining width was 0.4".  His next planned stop was California.  There's no way he would have made it. 

[srgtlord]

  Holy moly! Injection pump out of alignment much?