Serpentine Belt Broke

Background : 2003 VW Golf TDI with 175,000 miles, last TB service completed at 125,000 miles.

While driving last week, lost power steering, A/C and the generator light came on. At first I thought it would be the alternator pulley coming off due to mileage and reports of this. When I opened the hood, I found the belt broken (I'll post picture as soon as my wife returns with the camera). This seems quiet odd to me for a belt to break on it's own. All idler rollers spin freely, as do the alternator pulley and the A/C pulley. The power steering pump is not as free spinning, but I don't know if this is to be expected.

Should I replace the accessory belt and go from there, or is there something else in the belt travel path that might have caused the belt to break (other than a damaged / defective belt).

VDubsoon said:

The power steering pump is not as free spinning, but I don't know if this is to be expected.

Click to expand...

I'll bump ya back up and tell you that what you describe here is normal, and to be expected.

You should find out when the serp belt was last replaced. It should be replaced with the timing belt.

If this was the original accessory belt, or maybe the second (i.e. it was not replaced at 125k), only then might I be willing to pass it off as normal wear and tear.

EDIT: Make sure the (plastic) idler is still there. It's down low, below the alt pulley.

This was the second serpentine belt and was put on at 125k with the timing belt (first timing belt was done at 50k by the dealer due to noise of timing belt tensioner).

I expected the power steering pulley to have some resistance as it is not clutched.

The plastic idler pulley is in place shown in the diagram from the Bentley manual.

Thanks

Do you still have the belt?

If you do inspect it to determine the failure mode.

look to see if it is an original VW belt. if not you know it was replaced sometime, when the car was probably out of warranty, in the past

does the belt have many long cracks aligned with the ribs of the belt?
cracks across the ribs are ok.

those long deep cracks are a sign of an aging belt

if the belt looks new inspect the parts of the tensioning system.

VDubsoon said:

... The power steering pump is not as free spinning, but I don't know if this is to be expected.

Click to expand...

There's your problem. All the items driven by the serp belt, except for the crankshaft, should spin freely by hand with minimal resistance. Even the middle portion of the AC compressor.

-Jason

With regards to the power steering pulley, it does turn and turns rather easily. It just will not keep spinning like the other pulleys.

Inspect the old belt.

Look for hills and ridges in the Vees and high wear that might indicate an air conditioning problem. A locked AC compressor. This will only be a problem when the AC is on.

turn on the key, and hit the AC button, then select a cabin fan speed, so that the AC button lights up.

Now try to turn your AC compressor. Pick a time when the ambient condtions are 50 degrees F or higher, if you can. It should not turn easily, but it should turn. Look for lots of rubber dust and fuzz near or under the AC pulley.

As mentioned, a tensioner problem is also likely.

Dan

How can you be certain that the dealer did indeed change the original serp. belt? Were you billed for a new belt, along with all the other items that are due to be changed?

Can't be sure the dealer changed the belt at 50K when they did the service, but a local Guru (Roger) did the 125k and I was there watching/learning the whole time.

Pictures of the old belt?

Finally back in town. Here are the pictures.

Because the serp belt is not an expensive item, just have it replaced. The belt is a component and susceptable to failure due to manufacturing process or usage. At least you were able to get 50k miles out of it, meaning a use of about 4-5 years. My tdi belt has 79k miles with horizontal cracks along the rib bases(where the ribs are "glued" to the inside belt surface). I am waiting for it to break. Power steering pump pully should turn as long as turning force is applied. You need not buy the belt from the dealer when you can buy some brands for about $13, $19, $25, etc (brand such as Durablast, etc). Ask Pep Boys to get you one for the price you desire. TIP: If you can replace the belt yourself, meaning free labor cost, why buy an expensive one.

OK, finally was home enough to get the new belt installed. Done this morning and car starts up. Alternator pulley is turning. I have done some more searching for what might have caused the belt to fail after only 50,000 mi. Upon starting the car with the new belt there is a ticking coming from the serpentine belt tensioner (when I press on the black rod fo the tensioner, the sound goes away). I don't have the terrible squeek heard in TurkeySSR clip on the 1st page of this post.

http://forums.tdiclub.com/showthread.php?t=146580

As the car is at 175,000, should I go ahead and replace the alternator or alternator pulley as this is a known issue and both are original on my car?

Dodoma said:

Because the serp belt is not an expensive item, just have it replaced. The belt is a component and susceptable to failure due to manufacturing process or usage. At least you were able to get 50k miles out of it, meaning a use of anout 4-5 years. My tdi belt has 79k miles with horizontal cracks along the rib bases(where the ribs are "glued" to the inside belt surface). I am waiting for it to break. Power steering pump pully should turn as long as turning force is applied. You need not buy the belt from the dealer when you can buy some brands for about $13, $19, $25, etc (brand such as Durablast, etc). Ask Pep Boys to get you one for the price you desire. TIP: If you can replace the belt yourself, meaning free labor cost, why buy an expensive one.

Click to expand...

Everything you say makes sense except: 50k miles = 4-5 years? I drive 35k in one year average. Anyone driving a TDI for about 10-12k miles a year is barely driving.

I just had a belt failure too. The belt was OK but fell off. I ended up replacing the plastic relay pulley that is right above the AC compressor and below the alternator pulley. TDIparts.com has that for $25. Easy fix with the right tool.

50k is not 4-5 years for me. I do about 30k annually as well, so a little more than 1.5 years.

I will take it to autozone for battery/alternator test. My next order from TDIparts will include a tensioner to have on hand (likely the relay pulley too as it is inexpensive). Thanks.