Stinky's Still Stubborn
 

The Buck$Zooka has been leaving a crater in my account and bruises on my shoulder - I should have gotten the floor model. Why the Magnum ammo? I am stepping up to get Stinky ready for pulling a 5th wheel toy hauler, so stuff that was previously dismissed is now part of the hunt. No... the steering wheel and the headlights are not preparation for towing a 5'er.

Vibrations and noises - that has been my focus for the last month. I took Stinky to a multitude of mechanics and tire guys, and everybody had a different answer. Well... they were all right (as in correct). Tires, driveline, front bearings, and differential all needed attention. With this being the lower part of Da Big Stink, I liken the fix to a brigade of Benjamins beating his butt into submission.


https://cimg1.ibsrv.net/gimg/www.for...88a0618246.png


OK... I did the final alignment of the carrier bearing yesterday, and now the truck is so smooth that I can feel one cylinder come and go. The truck makes an odd noise when the cylinder misbehaves. Mind you, this is not a "miss" per se... it's a partial miss - or one cylinder is not getting the same treatment as the other 7. This is gunna be a real bugger to isolate, given how intermittent it is. It ran great in the morning, but the afternoon drive had the issue for about 30 miles, then it was gone.

I'm listening to the engine and it sounds more like a sewing machine (from the cab) than a diesel. When the problem begins, there is an "off-beat" cackle that shows up, I see the passenger-side EGTs ride about 50 degrees cooler, and I have to move my foot ever-so-slightly deeper - to maintain speed. This happens at full engine temp, and I haven't cracked the whip or anything like that to run the risk of introducing air into any of the fluids.

Ideas?

I knew I could count on you.

I'm still working out which character I am in this video:

Are you asking the students at AE University to figure out what their professor might have missed?

I thought somebody may have run across this problem with their truck (and solved it), in the hope it abbreviates all the troubleshooting I'm facing. It amazes me that one single truck (named Stinky) can have just about every problem encountered by all of the members' trucks combined.

I'll say this though - Stinky is one fine-riding vehicle (for a Superduty of this era), save for the intermittent failure to keep a beat. He's like me when I try to dance.

All that money sunk into it and it still isn't done?

Sent from my Telegraph using IB AutoGroup

So you have a 7 cylinder diesel, still one more than a 5.9 Cummins......so you got that going for you.....

With all that aforementioned advice I expect you've gotten 'er done already. I sit here wondering if I would even notice that skip in beat and if my truck isn't already experiencing it. 50 degrees cooler on the right should narrow it down a little for you though. As for me I'm clueless so all I can do is lurk and learn.

Mark

Maybe you have a poppet screw a little loose and it don't allow the injector to open fully causing a lean misfire condition.

What kind of oil are you using? Trying to KISS some trucks behave differently with various brands...

I'm running Chevron synthetic right now, but I'm about due for a change... I have Mobile 1 on the shelf. I'm mulling over whether I pop the valve covers, then change - or just change.

With the intermittent cool reading on the right, I suspect #7 (last one I touched before this started happening) - but that's not to say it couldn't be a hot-firing injector on the driver's side.

I do wonder about the poppet screw on one stick - it's worth a look. There is also the distinct possibility it's not the injectors - it could be something with a lifter, pushrod, valve, or spring.

It's too bad AE doesn't have an option to cut the injectors out one at a time to help narrow things down a little.

It's not a shortcoming with AutoEnginuity. It's simply not a diagnostic routine that Ford incorporated into the PCM/IDM operating systems.

If I had a 7.3L with almost 300K miles and it was still running (oh wait, I have two of them), I'd be happy that it was STILL simply running....

How about using one of those hand held temperature things that shoots the red light beam to get the temps? You could shoot it at each cylinder maybe at the exhaust part to see if it is #7?????

I have one, but it has a low limit. Even with that, 50 degrees difference at cruise won't show much of a difference at idle - if I can catch the damn thing in the act... it's intermittent.

I haven't ruled out a tired IDM either. I'm not saying it's out, I'm saying it might be an idea to try it, then keep the old one as backup if this does nothing. If it works, I can send the old one in for repair. I'm thinking long game here - who knows what price and availability will be, years from now.