Crank/No Start Analysis - Ford 4.0L Timing Chain Failure
This vehicle was brought to me from another shop that brings us stuff from time to time that they are working on and not getting the vehicle repaired successfully. This shop is 60 or so miles away from me and tows these problem vehicles to me, sometimes we repair them, sometimes they come get them without us repairing them, from there, I don't know if they repair or it gets declined.
This Explorer with a 4.0L (K) engine, with 136,653 miles on it firing order 142536 was brought to us with the crank/no start concern and a list of things that had already been replaced in an attempt to repair it. They replaced the spark plugs, throttle body, maf sensor, and checked out some wiring, they reportedly kept getting a code for the throttle body after all this and were now thinking they needed a wiring issue or computer repair or replacement, but wanted me to verify.
When the car arrived, I warmed up my gas analyzer, because I wanted to get a reading out the tailpipe to make sure I had plenty of fuel for the vehicle to be able to start. This is a picture of my gas readings cranking out of the tailpipe The readings show that I have plenty enough fuel for this car to start. While cranking I noticed the common timing chain rattle for this engine and that the rythm was not correct.
I now want to go in-cylinder and get a cranking compression waveform on two cylinders, one on each bank, two transducers simultaneously (different revision transducers) with an ignition sync for each.
After looking at those two, cylinders 1 (green trace), and cylinder 4 (yellow trace), I wanted to compare two more, Cylinder 2 (Green trace), and cylinder 5 (yellow trace). I see that on bank one, cylinders 1&2, that there is a lack of valve movement in both.
Just for grins a giggles, I stuck my inspection camera in the oil fill tube and recorded a couple of cam lobes while the engine was being cranked. There isn't any sound but you can see oil pumping when I was cranking the engine. Then I put all of the spark plugs back in and ran a relative compression test per a request from a friend. Thanks for taking time to read this and hopefully it helps someone in the future.
Thanks Rusty, very cool. I've never used a 5 gas but I was surprise to see that the HC displayed OL.
It has been my quick easy go to for fuel availability for many years now, personally I want to see a minimum of 6,000 ppm HC
Nice rusty .. this what makes u great . You actually gather a lot of data
Thanks sir! Though I am quite sure I don't meet the level you express...some day I will get there. Sometimes I get time to gather and sometimes not, depends on the day, I like to help by showing my ways for getting to the root cause. Seems to work for me.