Pump Belt Failure: Causes and Solutions

Hello.

After my car suddenly stopped working yesterday and wouldn't start, it was towed to the repair shop. I was able to fix it that evening - my wife's description of the problem was quite plausible - it simply wouldn't start. I suspected a broken serpentine belt, a faulty pulley, or a sheared bolt - things like that can happen sometimes.

What I saw next surprised me a lot – the belt literally disintegrated. It's not an original part, but it's also not cheap junk. Unfortunately, I can't remember the manufacturer, but the belt hadn't been installed for more than 50,000 km.
"If someone had shown me that and asked me, I would have thought it was contaminated with oil and that the oil had ruined it. But it never was, because I installed it myself. And I've already driven many kilometers with a timing belt. Many people drive the ESP belt twice as long and replace it every 120,000 km along with the timing belt."

Strange thing - thankfully, the main belt is okay and looks quite good. The roller and tensioner were also tight and everything seems to be fine.

See photos in the attachment.

Does anyone have an explanation for this?

Best regards,

Hello,

Quote:

Does anyone among you have an explanation for this?

It's possible that the belt was obstructed. These situations are always very frustrating when you purchase items that have been stored for years, painstakingly install them, only for them to fail shortly after.

Best regards, Rainer.

Yes, I had already suspected that. Especially when it comes to oil or brake fluid, one should ask more specific questions. That would be an explanation, yes. But – how long would a belt have to be stored in its packaging to age like that?

Does the belt show any signs of foreign objects - which are not visible in the photos - or was it overtightened?

We would also have liked to know the manufacturer.

Yes, unfortunately, I can't identify the manufacturer. Or rather, I can't anymore. It might be Hutchinson - I've been using their products for a few years.
"There's usually a manufacturing date on it as well, but it's all illegible. And, as I said, I've never really paid much attention to that before."
Okay, usually I keep a timing belt kit at home for about 1-2 years, so I can quickly grab it if needed (like yesterday).
However, I mean, if it's stored in the dark box in the basement, it won't age as drastically as it would in the engine, right?

No foreign bodies were detected.

Best regards,

roorback wrote:

Yes, I had already thought that. Especially with oil or brake fluid, one should ask more specifically about that... that would be an explanation, yes. But - how long does a belt have to be stored in its box to age like that...?

So, I once threw away a timing belt for a 1.6 D engine (54 hp naturally aspirated diesel) that, even after 20 years, looked quite new at first glance...

Okay, it's a big difference whether he has to wait 20 years or just 2 years at home for the installation.

But one thing I've learned is that I will always pay attention to the date in the future, even if it's difficult to decipher for many people.

It's questionable whether you can return a belt if it's a few years old. Where's the line? It's like with tires – I once encountered a situation where they wanted to sell me tires that were 3 years old, which I refused.

Quote:

Where is the line?

It is difficult to make a definitive statement about that. I consider half a year to be acceptable.
First and foremost, it depends on the quality of the materials.
Two weeks ago, I replaced the timing belt on a 1.9 TDI PD engine. The car had only 45,000 km on the odometer, but it was 10 years old. The timing belt still looked like new.
At Ford, it is sometimes stated that the timing belt needs replacement after 150,000 km or 10 years.

Hutchinson is an OEM manufacturer. Nevertheless, I would opt for well-known brands, such as Conti or Dayco. I honestly feel a bit uncomfortable with Hutchinson. This is due to experiences I had in the distant past.

Is everything sealed properly at the pump?
hg
Herbert.

Hi!

No, I don't think the belt is to blame.
I've seen belts like that that have lasted for maybe 15 years or more.
in older LT models, for example.

It will likely have a mechanical cause.
Pump stuck, seized?
Foreign objects?

Hm, I don't recognize that manufacturer .
"Wie Autoservice Schreibt" might be a weaker rhyme. Perhaps there are foreign objects present, as the pump belt in these 5-cylinder engines runs quite freely and is not well protected.

I don't think it's due to aging. I only had one instance with a Renault diesel where a Conti belt, which was about 4 years old and had 70,000 km on it, failed ("toothed" belt missing teeth), and the cause was unclear. The valves and hydraulic lifters were flat .

From friends who own a 1st generation Golf 1.6D vacation car in southern Spain, this car has only about 65,000km after 32 years, and the timing belt has never been changed. It runs perfectly .

Hello.

As far as I can tell, the "hardware" is okay. Specifically, the pulley and pump seem to be fine. I did replace the pump once because the old one was leaking, but the leak was towards the bottom, near the fuel injector (at the back) - the belt wasn't affected.
After the layer of material that was attached to the gum completely detached, I believe the adhesive bond has failed.

It's hard to say if there's a foreign object, but I definitely installed the belt guard.

The tensioner was no longer engaged - at first, I thought the screw might be loose. So, the top part was completely raised. But looking back, I'm sure that's because the belt has become longer. I assume the tension was correct, especially since I always check these things regularly!

Okay, this belt definitely wasn't a Hutchinson belt. Although I have the same supplier, they used different materials about 4 years ago. Because I have/had so many cars, it's very difficult to trace which delivery the belt came from. However, I will try to figure it out – I usually make very detailed notes about these things.

If the problem is caused by the pump or the camshaft wheel, it will happen again.

Best regards,

Quote:

After the layer detached completely from the rubber with its teeth, I believe that the adhesion had failed.

This, in turn, would suggest the influence of diesel or oil.
hg
Herbert.

Yes, Herbert - that's exactly what I mean. Maybe I've overlooked something.
As I said, diesel fuel doesn't normally make its way that far from the pump - the leak was coming from the injector control valve (cover on the back) and was dripping downwards - the valve cover and the SIR (solenoid intake rocker) are fine.

Okay, some things just have to be accepted as they are – there's nothing you can do about it. Even though I'm a very detail-oriented person and I document everything, and even make time for it, I didn't happen to write down the manufacturer or date of the strap in my activity journal...

Basically, I can only keep going and maybe check more frequently.

Thank you.
Best regards,

I just remembered: Is the fuel injection pump really properly secured? Background: We had a T4 Transporter that had more than 800,000 km on it, and on that vehicle, the ESP belt would repeatedly tear after about 10-30,000 km. The reason was a LOOSE ESP on the engine, where a bracket had broken off. You wouldn't notice anything unless you look very closely.
Replaced with a motor from another owner, and it's been quiet ever since.

I will check that, thanks for the tip!