Engine knock with poor compression

[the_twig_187]

I have a 2011 F-350 6.7L with 85,000 km and I have the feeling I' m going to replace the engine...

 

codes for a misfire on cylinder 7, IDS compression test indicated a 10% loss on cylinder 7 with all other cylinders at 0%

 

there is a noticeable knock as well when running the engine

 

anybody have any experience with related issues?

[Bruce Amacker]

What are the hours and idle hours?  Do you have any maintenance history? 

 

In all of the 6.7 classes I've done, only one cust has any engine failures, and it's from a gross neglect/lack of maintenance (by hours).

 

[the_twig_187]

build date is -Feb 2010

km is -83,675

engine hours is -2494

idol hours -886

 

they  service the truck at a "lickey lube" service shop (cheapest price I guess) and we are having them bring in all the service records for the truck

[Bruce Amacker]

Avg MPH- 20.8, not great, but certainly not terrible.  58 miles per idle hour, about the same thing. Ford and IH use 33 avg MPH is what they like to see, I like 100-200 miles per idle hour as a good number.

 

Probably 70-80% of the trucks I teach on have number similar to yours, only a few times I've seen avg MPH above 30.  If maintenance is good it's probably a fluke. I wonder if the oil is rated CJ-4? Sometimes the cheap stuff in the tanks is not......

 

[Matt Saunoras]

Build date falls well within the run of exhaust valve failures

[the_twig_187]

that's exactly what I was thinking....exhaust valve meet mr piston lol

[lmorris]

If its running I would lean to a bearing failure. Just finished one with #7 wrist pin bushing pounded out. No other damage. Due to lack of parts I installed a long block.

[mchan68]

It appears I have my very first 6.7 base engine issue that has landed on my doorstep. I was going to try and move it, when all of a sudden, all I heard was BANG!!! Along with some metal parts scattered on the ground in our parking lot. Now the engine is completely locked up. Anyone have any detailed cab lift instructions on one of these, they'd care to share?

[tonybullitt]

It appears I have my very first 6.7 base engine issue that has landed on my doorstep. I was going to try and move it, when all of a sudden, all I heard was BANG!!! Along with some metal parts scattered on the ground in our parking lot. Now the engine is completely locked up. Anyone have any detailed cab lift instructions on one of these, they'd care to share?

There is a very nice one on here under the tech resources. I have used it several times myself.

[tonybullitt]

http://www.forddoctorsdts.com/download-2.php?f=2011SuperDutyCabRemoval.pdf

[cbriggs]

At least there is ample room to unbolt the converter from the flexplate once the engine and converter are pulled. I have done lots of these for bearing failures, only one was locked completely.

[Alex Bruene]

I've had a few with major bottom end failures.  Normally, you can rotate the engine in both directions to get the convertor unbolted. Normally.

[the_twig_187]

so I have a confirmed cause and repair for the engine knock with poor compression. the customer replaced the number 7 injector hold down as he claimed "it was broken" he also claimed that he torqued the hold down bolt to the ford specifications. I removed the cab and prepared to pull the head to investigate the engines internals (as we thought it would be warranty at this point) when I was removing the injectors as part of the head removal process I found the #7 injector hold down bolt was finger tight. The injector was carbon fouled and destroyed by the flame front passing up the injector bore. This was the cause of the poor compression, misfire and engine knock (blow by). I gave the customer 3 options as this concern was no longer going the warranty route. they chose the route of replace the injector and re-seal the others, re-assemble and hope for the best. That's what I did and when starting and running the vehicle is very smooth. compression is back, the misfire is gone and the engine is very quiet (no more knock)...for now

 

so this is a complete repair and my first cab off repair....I lost my virginity

[tonybullitt]

The dumbest part is had the customer brought to you with broken hold down he could have gotten that warratied and saved the hassle and $. I ran the 9c334 base # with 85,000 km and it said is covered. Chris check out tsb 14-0233

 

 

TSB 14-0233 6.7L DIESEL - VEHICLES BUILT ON OR BEFORE 2/12/2012 - RUNS ROUGH/MISFIRE - BROKEN INJECTOR HOLD DOWN CLAMP - BUILT ON OR BEFORE 2/12/2012

[the_twig_187]

Yah I know... It's a landscaping company and they replaced an alternator on another truck only to bring it to me when the battery's wouldn't change. Found a brake in the genmon wire from the alternator to the pcm. Overlayed the wire and fixed it... Cost them an alternator for nothing... Same with this truck they decided to "fix" the hold down themselves and "poof" warranty turns into retail

[8WA Sman]

Like this one http://www.forddoctorsdts.com/topic/5429-whats-in-your-bay-part-v/page-14?do=findComment&comment=54496

[forddieseldoctor]

You guys tie your super cab's down when you lift them? The only ones I ever think of tying is the regular cabs. And that's just a 1" strap on each side that goes from a hole in the underside under the hoist arm and then up to the seat frame on each side.

[the_twig_187]

our shop foreman is super anal about things like tying down a cab that is 8 feet off the ground. Which is a good things because its always better to be safe than explaining why a cab fell. we have straps that are mounted to an arm bracket which slides and pinch bolts onto the hoist arm (made specifically for cab offs). then we throw another strap on overtop of that hoist mounted hold down strap. then when the cab is in the air and on the highest set of locks. We use old body bolts through the eyelet of the strap to mount a third strap to the frame of the truck on the ground so that the nose of the truck doesn't get any ideas... like I said its way overkill but it ensures we never have to explain to the dealer principal "so first the cab started falling over....and then it fell over!"

[Alex Bruene]

I used to only use 3 hoist arms to lift regular cabs on that hoist.