Mechanical Failure woes in the Rust belt

Brian Diagnostician Willoughby, Ohio Posted   Latest   Edited  
Case Study
Trained By Techs
Driveability
2011 Ford F-150 FX4 5.0L (F) 6-spd (6R80)
P0308 - Cylinder 8 Misfire Detected

Living in the Rust belt has it's Pro's and Con's. Most that live in the warmer climates tend to only see the cons but that's ok. I live in North East Ohio in the highest recorded snowfall city in Ohio and this is home for me. Born n Raised with no intentions of ever moving (again). 

Rust is always an issue here. I've learned to respect it. Rust breaks cars and broken cars brings us WORK. However, in this case, Rust plays a major role in a customers decision to invest in a costly repair. 

I had a 2011 Ford F-150 arrive at the shop with a misfire complaint. The misfire is very consistent but I wouldn't call it a "dead misfire". The engine had a slight shudder every engine cycle but it wasn't enough to cause the customer to have a complaint of it running poorly. His concern simply was "The check engine light is on but it runs great" However, I myself feel the shudder. Subtle, but it's there. 

After a code-scan revealing P0308 Cyl 8 Misfire I decided to listen to the "cranking cadence". A simple trick I like to do is push the throttle to the floor to initiate "Clear flood mode" and simply listen to the way the engine cranks. Sure enough I hear an irregular cadence from the engine. There is a slight hiccup in the rhythm. 

RELATIVE COMPRESSION TIME! One of my favorite tests that we at Trained by Techs have covered many times in many ways in our videos. I included an Ignition sync from #1 ign coil here 

Using the firing order … and a sync on #1 I was quickly able to prove that #8 Cylinder has been affected by some type of compression loss or reduced cranking effort

I decided to add a 3rd channel using a First Look Sensor to the intake Manifold which becomes a very powerful combo when diagnosing mechanical faults

You will see a pressure rise in the intake manifold when # 8 cylinder approaches TDC. This is potential evidence of compression leaking past the intake valve causing the volume of air in the cylinder to escape and enter the intake manifold during the #8 compression stroke. 

I decided to take it one step further to help solidify the diagnosis by going In cylinder using a WPS500x. 

The Deep vacuum pockets near bottom dead center is further proof of air volume loss resulting in a pocket differential of 9 PSI

This vehicle needed to have the heads removed and repaired however the customer opted out on the repair. 

His excuse was RUST. The focus of this article was not only my attempt to share what I thought to be an interesting case study but more so to vent frustration. Do any of you that are in the northern states deal with issues like this? When the vehicle is only 8 years old, low mileage, and require extensive mechanical repair, do you find repairs are getting declined due to the condition of the rest of the vehicle? He claimed the vehicle wouldn't last much longer due to mother nature doing her thing and decided to drive the vehicle until the engine blew up. 

I thoroughly enjoy mechanical diagnostics and have been to many classes including one of my favorites from Brandon Steckler on pressure analysis but continue to be in the situation where a mechanical fault results in testing only.

Special Thanks to Brandon Steckler for the training he provides for mechanical testing. He is, in my opinion, one of the best at it! If you haven't taken his pressure analysis class or ANY class he offers, SIGN UP! You will not be disappointed. 

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Chris Diagnostician
Commack, New York
Chris Default
 

Love it Brian!! Love the custom colors on the screen captures!

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Brian Diagnostician
Willoughby, Ohio
Brian Default
 

Special thanks to my Boo who referred me to a great piece of software called Jing to annotate screen captures very easily. ;)

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Thomas Diagnostician
Saint Petersburg, Florida
Thomas Default
 

Hi Brian, long time. Do we see the rounded pocket there, as the air leaks?

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Thomas Diagnostician
Saint Petersburg, Florida
Thomas Default
 

meaning, a suspected good capture may be helpful....

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Andrew Technician
De Motte, Indiana
Andrew Default
 

I dig it... I am going to have to find it for myself.

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Sheldon Diagnostician
Port Moody, British Columbia
Sheldon Default
   

I love it when someone uses data to prove their hypothesis. Awesome job! Can I ask what you charged for diag time in hours?

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Brian Diagnostician
Willoughby, Ohio
Brian Default
 

This vehicle was billed at 149.95 (our typical charge for most diagnostic work) We will charge additional if multiple systems are affected or it if the complexity is greater

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Martin Diagnostician
Burleson, Texas
Martin Default
 

I'm so glad I live in a rust free state. People here will invest their money into an 8 year old vehicle all the time. 3-4 thousand is way cheaper than a brand new truck. Usually the rest of the car is in great shape. Heat is what breaks them down here in Texas. Lots of AC work. Thanks for the write up! Good stuff!

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Randall Owner/Technician
Kalkaska, Michigan
Randall Default
 

Brian My sister lives in central Wyoming. When I am there, I am amazed at the vehicles from the 80's running around with sun bleached paint and rock solid bodies. I live in the snow belt of northwestern Michigan and we seldom see the sun more than a few days a month from Nov. thru March. Salt and sand are on the menu virtually everyday through those months. What you describing, I call the

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Jaxon Technical Support Specialist
Stafford Heights, Australia
Jaxon Default
 

Brian, I hear your frustration. Thank you for a very clearly written and informative case study.

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Geoff Diagnostician
Lahaina, Hawaii
Geoff Default
   

"broken cars brings us WORK" - Nice! Broken cars bring us people with no money to pay for work :-( Rust is never an issue here. Everyone being broke is. Eight years would be on the "new" side around here. But the result is the same, they don't fix it, so you have my sympathy/empathy my friend.

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Joel Diagnostician
Soquel, California
Joel Default
 

was that incylinder pressure transducer wave form taken at idle ? is because of the intake valve opening call my attention.

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Brian Diagnostician
Willoughby, Ohio
Brian Default
 

All captures were taken while cranking

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Joel Diagnostician
Soquel, California
Joel Default
 

thank you

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Brian Owner
Parma, Ohio
Brian Default
 

Excellent Brian, Being in the NE Ohio rust belt as well , and mobile in the past 8 years I have seen many situations that the vehicle is traded in or the dice are rolled and they drive till it fails E check or just stops. It can be frustrating to spend a hour or more diagnosing and not get to see the vehicle repaired, along with the customer getting a new (or used) vehicle that the dealer

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Chris Diagnostician
Commack, New York
Chris Default
 

Tell me more about Flash Back Express...

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Thomas Owner/Technician
Constableville, New York
Thomas Default
 

My shop is located in upstate NY due east of lake Ontario in the tug hill region where you see the "major lake effect snow storms" many times measured in feet. So with that being said we deal with a major amount of rust from the salt and sand on the roads. I have mixed responses from customers when it comes to repairing a rusted vehicle. Many here simply can not afford a new one so they opt to

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Brian Owner
Parma, Ohio
Brian Default
 

Its pretty simple just open the program and hit record and it grabs what ever is displayed on your monitor, I have had mixed results with the audio recording, most likely my lap top mic. I use the free version.

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Ray Diagnostician
North York, Ontario
Ray Default
 

This is an issue to watch out for when the WPS500 in a cylinder cranking compression is low and the wave form looks like a leaking exhaust valve. This vehicle is an 06 Ford Escape 3.0 cranking no start. In the first capture, CH B is a FLS on the dipstick tube and the high pressure pulse in the crankcase lines up under the low compression cylinder in the CH C relative compression amps. Which

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Joel Diagnostician
Soquel, California
Joel Default
 

what was the real problem to replace the pcm , flloding cylinder with too wide injection pulse??

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Ray Diagnostician
North York, Ontario
Ray Default
 

Maximum cold cranking injector on time is usually 20ms. Some cylinders were fuel washed because some injectors were spraying too much fuel because of a bad PCM

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Joel Diagnostician
Soquel, California
Joel Default
 

thanks for Sharing

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Dmitriy Analyst
Toronto, Ontario
Dmitriy Default
 

Incredible story, Ray! It deserves a prominent spot on the front page, in my opinion.

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Ray Diagnostician
North York, Ontario
Ray Default
 

Thank you Dmitriy!

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Scott Manager
Claremont, California
Scott Default
 

I agree and hope to see this posted as a new case study Ray!

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Andrew Technician
De Motte, Indiana
Andrew Default
 

I have lived and worked in the NW Indiana/South Chicago Land area my entire career. I have bought many good vehicles from customers because of "rust". Fixed them, flipped them, or drove them myself for years. (wife gets the new cars I get the beaters and the Harley) . But, I have worked with some of the best service writers I could have ever asked for. At one shop, they could calm a customer

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