Last thursday I recieved a phonecall from a friend of mine returning home for spring break, telling me that as he was cruising at around 70mph the engine suddenly stopped running. It was somewhat on my way to work so I met him on the side of the freeway and started diagnosing why it suddenly stopped. I first popped the oil cap off and told him to crank it. Sure enough the cam was not turning.
I knew his timing belt had been replaced around 35K ago (about 10K before he bought it give or take) so I was curious as to why it decided to break.
We had the car towed to his home and I went over and pulled the front end of the motor off. What I saw was very interesting.
The top bolt of the timing belt tensioner had been replaced with a stud, and a really crappy nut had been used to tighten the top of the tensioner. Over time the bolt slowly backed off causing the tensioner to angle slightly, causing the belt to rub.
Here is what the belt looked like when it snapped.
The belt itself was in great condition, and showed accurate wear considering its age, however the belt is about 40% of the width that it should been. We also found a black powder which was what was left of the rest of the belt. As the car was driving, the belt was slowly being shaved away until it suddenly snapped.
Overall damage was 4 bent valves, and one broken intake rocker. The head survived pretty well, and is rebuildable if need be, however we are replacing it with a used head off my spare M20.
Here are the rest of the pictures.
So let this be a lesson to everybody, Even if the belt has been replaced by the previous owner, it MAY be worth the time to inspect the work that had been done.
I knew his timing belt had been replaced around 35K ago (about 10K before he bought it give or take) so I was curious as to why it decided to break.
We had the car towed to his home and I went over and pulled the front end of the motor off. What I saw was very interesting.
The top bolt of the timing belt tensioner had been replaced with a stud, and a really crappy nut had been used to tighten the top of the tensioner. Over time the bolt slowly backed off causing the tensioner to angle slightly, causing the belt to rub.
Here is what the belt looked like when it snapped.
The belt itself was in great condition, and showed accurate wear considering its age, however the belt is about 40% of the width that it should been. We also found a black powder which was what was left of the rest of the belt. As the car was driving, the belt was slowly being shaved away until it suddenly snapped.
Overall damage was 4 bent valves, and one broken intake rocker. The head survived pretty well, and is rebuildable if need be, however we are replacing it with a used head off my spare M20.
Here are the rest of the pictures.
So let this be a lesson to everybody, Even if the belt has been replaced by the previous owner, it MAY be worth the time to inspect the work that had been done.
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