Daily writing prompt
How has a failure, or apparent failure, set you up for later success?
It was somewhere in the early 2000’s I got my hands on a Sun Oscilloscope for the second time in my career but this time I was more grown up and had regrets about selling my first one without giving it a fair chance to become part of my everyday tools.
One of the first tests I learned was the relative compression test, if you don’t know, this a very fast way to identify loss of compression in a cylinder by reading how many amps the starter requires to turn each cylinder over. Used with a sync on a second channel it can pinpoint the exact cylinder or cylinders that are affected.
This, as good and easy as it sounds comes with a word of caution.
Firstly it does not tell you the actual compression it only tells you the stronger and weaker cylinders.
Second, a lot of factors can show incorrect readings. Such as a faulty starter motor.
But where it caught me out was with a condition called cylinder wash. This is where there is so much fuel flooding the cylinder that it washes the cylinder walls and thus it affects the compression in that cylinder.
In my case it was cylinder wash, coupled with an impatient customer who needed his car back ASAP. My problem started because I was not the first mechanic to look at this and it had been turned over so much that the cylinders were saturated with fuel.
I was keen to get this job done fast and to use my new found test with my scope.
I could see cylinder 4 was much lower than the others so I concentrated on that.
There is enough compression to start
This is where I wasted a lot of time. I needed to prove this loss of compression before I dismantled the top half of this engine.
I had spark, fuel pressure and some amount of compression on at least three cylinders. My head was into this low compression cylinder so much that I lost sight of where I was going with this diagnosis.
Eventually after walking away for a few hours I came back in a different state of mind and got to the bottom of this issue, which by the way was a failing fuel injector which was over fueling on that cylinder and a case of bad service history that the spark plugs had just given up.
I always remember this as one of my very near biggest mistakes, I was so close to taking the head of this engine it’s not even funny.
It was a lesson that taught me a lot about making assumptions and giving in to the pressure from a customer. Not quite a failure but it was so close, it creeps into my subconscious a lot.
