I did a motor swap on my 2005 Excursion 4wd v10 over the course of the last two weeks old motor came out new motor (reman from AER) went in everything is in and hooked up motor runs great! However I am having a rather rough pulsing vibration while driving. When idle in park or neutral it’s almost not noticeable when in gear with foot on the brake you can feel the truck with a sort of throbbing vibration. Let your foot off the brake and drive at “impulse” speed the truck almost lopes press on the gas and the vibration gradually gets worse the higher the speed, 45 and up it’s scary to drive.

i made sure that the torque converter lined up with the flywheel the exact same way it came apart however I couldn’t find a for sure way to tell if I installed the flywheel the same way it came off the old motor, there were no “keys” for it to fit into there were not markings to reference off of, and the bolt holes lined up anyway I put it on so I didn’t figure there was a specific way it was supposed to line up, my first thought was a “grounded out” motor or tranny mount so I loosened them all up popped the throttle several times shifted from reverse to drive drove off the cliff of a curb I have in my drive way and back up it several times even with the mounts loosened I could still feel the pulsing vibration, tightened everything back up and it’s still there,

I am thinking that I might have a bad/ I might have broke a motor mount but I would like to diagnose all options before I start throwing parts/more money at this truck. So I figured I’d tap into the wealth of knowledge here and see if anyone has any ideas or somewhere else I can look see if I can find my problem.

any ideas or advice would be a great help

 

I'm a bit confused by the combination of words... vibration-pulse-impulse-lope. Go with the best word to describe the issue.

Does the truck surge? or does the engine RPM's vary? Assuming the engine runs fine, you said it runs great, then the transmission would be my guess.

 

Did you add a quart of ATF to the torque converter before you installed it? Have you checked your transmission fluid level?

Put it in neutral and see if the vibration varies with engine speed. This will diagnose an imbalanced engine.

Put it in Park and increase engine speed to see if the vibration occurs or varies. This will diagnose a bad (or empty) torque converter. Note that your engine revs will be limited to the stall speed of the torque converter

My experience is that the bolts on the back of the crankshaft are almost never evenly spaced, deliberately so you can't install it "wrong". The TC-to-flexplate orientation is far more important than the flexplate-to-engine orientation, if they are a balanced pair. Usually these parts are balanced individually, so that you don't have to rebalance a flexplate when you install a new torque converter.

 

 

 

Where you at in TX, Rob?

 

Did you check the drive shaft, I had the double cardan joint and centering ball go bad, and it did very similar while moving. It was scary loud at higher speeds.

 

Nicmike, I was at fort hood I just looked at my profile it was way out of date I updated it I am now at Sill in OK

 

I replaced all the ujoints on both drive shafts and front axle about 10000 miles ago as well as ball joints, I don’t think the issue is there but I will def check when I get home from the holiday travels, I’m gonna start with the torque converter to fly wheel mating first and work my way back in the drive train until I find it, thanks for the suggestion

 

Soooooo update... just so everyone that has been following is aware I am smashing my head against the wall as I type this! So I pulled the trans, not completely out of it I left it on the jack and sorta scooted it back enough to mess with the flywheel and TC, as I suspected the flywheel was mounted correctly however I didn’t notice it before while I was doing the motor swap but there it was in all it’s glory two almost identical yellow paint marks on separate TC studs and flywheels holes , the mark I made when I disconnected it and another mark from someone else, the only way I knew for sure which mark was which different shades of yellow but not so different that it was obvious, and of course I installed them back together wrong just my luck (I’m still smashing my head on that wall) so I’m happy to report that the truck went back together the right way and almost all the vibrations are gone! It’s smooth again except for at speeds upwards of 50 plus mph and this time it feels like tires are out of balance but emediatly goes away when I release the gas and returns when I reapply the gas, so I’m gonna have the tires checked for balance (but I don’t think that’s the issue) I’m leaning towards bad u-joints, I spent one winter up at fort drum and the joints look rough, they felt smooth when I manipulated by hand but they look rough so might as well replace yet again see if that fixes it unless of course anyone here has any other ideas?!?

 

Good news then :-).

The other vibration sounds like drive shaft slip joint.

 

Last update on this issue!!!!! I have found the problem!!! I spent the day tinkering around checking everything I could think of as well as many of the suggestions I have received from y’all so I am happy to report (and slightly embarrassed to admit) the issue was a misfire. I have never experienced a misfire on a motor this large before so I didn’t recognize it right away what happened was several of the locking pins on the fuel injector connectors broke when I removed the wire harness from the old motor, I didn’t want to fork out the 45 bucks per for the replacement connector from ford and I didn’t want to “special order” a new harness from ford so I used a little hillbilly ingenuity and tried zipting the connectors tight to the injectors I thought all was well but as I found tinkering around today the rear right cylinder wasn’t fully seated, ya know the one tucked all the way in the back under the firewall and heater/ac plenum..... a slight push on that connector and BAM perfect running truck as well as massive embarrassment and anger and a whole plethora or other emotions I dare not mention for fear of getting in Trouble ha ha ha

 

Awesome find, you've got me slowing down trying to find my miss problem.