Autonerdz forums

Since i have had my pico I have become proficient in diagnosing engines that are out of time by using cam and crank patterns. Pico 101 if you will.
Well, this week a customer came in with a 2011 Silverado that was running bad and had a cam/crank correlation code. First of all, i have never seen that dtc in an ls engine and we see hundreds of them at our shop. Anyway, after about 15 min I had my scope hooked up to the cam and crank sensors, recorded a pattern, found a known good one, and determined the engine timing was retarded by 13 degrees.

We had put the reman engine in for the customer and it was still under warranty by the national engine/transmission company.  So I told my service mgr I wanted to pull the timing cover to verify my diagnosis and find out what happened to the timing chain components.

After several days of back and forth with the company telling us to do this test, that test, everything except pulling the timing cover, I asked my service mgr why they won't believe my diagnosis and let me pull the cover and he said... "They don't believe in all that computer bull crap, they want us to do REAL tests!".  Really???  The truth is I know my svc mgr doesn't believe in it either, but why wouldn't a huge company that rebuilds engines and transmissions?

Even after I have proven in case after case that LSD is accurate and quick...they still doubt it.  Does anyone else run into this or is it just in my small town?

Anyway, the end of the story is the company finally gave us permission to pull the cover and guess what I found...a broken timing chain guide and a floppy chain!!! Imagine that!

https://www.youtube.com/watch?v=xFElnOuzWKw

and the lefties are burning books and rewriting history.

Tom is the last guardian in the automotive world of reason.

Thank you Tom

Saw an excellent comment on iATN from Tim Wheeler.

http://members.iatn.net/forums/read/msg.aspx?f=forum8&m=206302&fv=0&ar=0

For those that can't access, he was responding to someone there that is a literal fountain of disinformation.  This person was stating how the scope is a very efficient way to waste a great deal of time.

Tim's response was that this happens when a tech tries to learn the scope on a broken car.

Nailed it.

I recently had to re-certify my ASE tests, and to my surprise a few scope questions popped up dealing with cam crank correlation. Good for ASE and their question writers.

Now I just hope I got it correct 

I am of the opinion that people believe what they understand. Make your findings relatable to "real tests". You can bring others over to the other side, or treat them like they are ignorant. People don't like being treated like they are ignorant. Everyone of us is ignorant to a certain point, and we probably learned from leaders that had an understanding of that.

Bill Hamilton wrote on Nov 16^th, 2019 at 7:30pm:


Excellent response!

Ronald Reagan said it best. It is not that they don't know something, it is just that what they know is WRONG.

SEANY MAC.  Excellent thought on the algebra question. One teacher if you showed your work would give you 95% if you added a simple addition error, or whatever?, then proceed with it from there. Then if your process was right and you make another error, it is now 90%, and so on.

Meaning why throw the baby out with the bath as you just made a human error, should not flunk the class from it. Now if you refuse to show the math the final answer if (100% wrong) if not the right number.

Good stuff, StitchB