Rattle and vibration - not typical - at idle and around 1350 rpm

[davlun]

So moving the torque converter back and forth is ok?

I thought I messed things up maybe by getting things out of line moving the torque converter back and forth... thought I recalled reading online that if you put it in the wrong direction, it messes up the values and alignment and then when you start it up, things get jammed up.

 

[davlun]

I know this may seem like a simple question when you have done this stuff before or learned over time, but it is all new to me. I cant afford to rebuild engine if something goes wrong...

 

[LCAM-01XA]

So moving the torque converter back and forth is ok?

I thought I messed things up maybe by getting things out of line moving the torque converter back and forth... thought I recalled reading online that if you put it in the wrong direction, it messes up the values and alignment and then when you start it up, things get jammed up.

EVERYTHING inside the engine that is supposed to move is also tied together by gears, there's absolutely NOTHING that you can get out of alignment by turning the engine over by hand in EITHER direction. We just had to drop a new lift pump in our truck, that crank got turned back and forth like 1500 times till we had the cam stop in a good position. By the way I strongly dislike using the starter gear teeth on the flexplate or flywheel as a prying point to turn the engine over, 15/16" socket on the crank bolt with a short extension and a 1/2"-drive breaker bar make things much easier and faster - obviously turn the crank only clockwise then, or the bolt may back out on you (never had it happen, but it's possible) and you'll have to retighten it (no big deal).

So then the converter studs are tight - this is good news. Did you try moving the flexplate fore-aft to check if she's cracked around the crank bolts? I can't see the picture you posted of what you found under the dust cover, but IIRC most flexplate issues have been reported by people with the new-style flexplates that are just stamped steel with the starter ring gear welded to that. The old style is the C6 type with a massive flywheel with the starter teeth machined into it, the flexplate is behind/inside that - those seem to have little issues as the flywheel dampens the diesel's vibrations, IMHO switching to the newer style flexplate was not a good move on Ford's side... So which style do you have, flywheel or not?

Also regarding possible converter noise, yes if she's slipping the lockup clutch that would only be noticeable in 3rd and 4th, however if something else is coming apart inside there (like for example the bearings between the turbine and the stator) that would make noises like you wouldn't believe. Your delayed engagement of 1st or reverse, does it only happen after the truck has been sitting for a while? Or do you experience it all the time now? I'm thinking if it's just after a long rest the converter could be draining down back into the transmission case/pan... How long do you wait after you fire the engine up before you shift into gear? Takes a short while for the converter to fill back up if it's empty, if you just light her off and then go for launch then yeah she'll dilly-dally a bit before she gives you the selected gear.

 

[davlun]

Awesome to hear. I know a lot of what you hear out on the web is junk, but wanted to wait just in case...To all who provide so much info, thanks. Went and got some new bolts after my last post, the ones that were on there were rounded over, very tight and hard time getting them off. Couldnt find any bolts with the built in flange so picked up regular bolts and washers. Think I am messing up the pictures when I put them up... will try again.

For timing in starting and then it actually moving, it is much more noticeable after it has been sitting. It sat for the last week and when I went to take drive it yesterday, IIRC I started it up, put it in reverse, but just let it sit without gas until my test push on the pedal seemed like it was ready to go. After that, seemed better. My other ford with the same trans (it is bad, have to let it warm up before it works right, shop said pan was had metal in it, needed new one soon, that was a year ago) feels the same way to get going.

For the flex plate, I did try using my hands to move it forward and back, didnt see any movement. Am I supposed to use something for leverage to try that? It looks like the one you describe, stamped with rim, can see a weld in pic below. Here is the pic from earlier, and a couple I snapped of the flex plate.

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To clarify, the noise at idle is not loud compared to the engine, and mostly heard when crouching down/under by the front wheels. Sounds like a piece of metal tinkling/rattling. Not constant but getting more so as time goes by. If you give it any gas, the noise seems to go away or is masked by the engine noise.

For the sound when driving, it may be related, not sure as I dont know what is causing the first part. It is much more noticeable when driving really easy and then backing off the pedal some to let rpm come down into 1450-1350 range. As it passes through that range, you hear it, the range seems to be increasing. If you give is some pedal from start, dont hear it at all, but engine is also a lot louder... On gassers I have been pretty good at identifying where a sound is coming from, but while I love the sound of my engine, I am confounded by the loud sounds of the engine to track things down. I am trying to track these down as they were not there when I first drove the car, seems they should not be there now.


I am learning, baby steps...

 

[LCAM-01XA]

Yup, that's definitely the problem child alright! Honestly idk how to move them, when our truck was still an auto we had the older flywheel-style plate (still have it somewhere actually, who knows when it may be needed) and there was no moving that even if the plate was cracked (which it wasn't). But I'd imagine that if you couldn't rock it fore-aft and side-to-side by hand then it's probably okay, if you used a tool to pry on the flexplate it would live up to its name and flex a little bit just cause it isn't very rigid/stiff by design.

 

[davlun]

See my last post if you have a minute, edited it to have some more info on the sounds. Not sure where to look next. I waiting a long time and intend to have this truck even longer and need to keep up on maintenance and prevent small things from getting to be big. Maybe I need to take it on a road trip to a good shop that really knows the older idi diesels. My ears will get better at picking out sounds over time, even if I dont know how to fix it. Have a good ear, just no real mechanic skills... yet.

 

[LCAM-01XA]

Yeah, your idle sound sure sounds like our stupid vacuum pump clip rattling. I know you said you couldn't find such a clip on your pump, maybe you don't have one, but we certainly do - well, did, not anymore, had the vac pump off for the fuel pump job and remembered to yank the stupid clip off. Forgot to take a pic of where it lives, but I think the commander in chief took ne of it after she forcefully removed it, I'll see about posting it tomorrow for you.

Another possibility is you have a piece of lift pump actuator lever (or maybe even the whole lever) laying somewhere in your pan leaning on the oil pickup screen - ain't no checking for that tho, only way to find it would be dropping the pan. Suppose you could try sticking a strong magnet to the oil pan to see if it will catch whatever may or may not be inside the oil pan and thus make the noise goes away...

Harbor Freight has mechanic's stethoscopes for cheap and they do work decent enough, may wanna grab one of those and see if you can locate the source of your idle noise yourself?

Driving sound, see that's the problem with these engines, they are stupid-loud to begin with, even worse if the sound insulation around them has been removed. Could be something in your transfer case too, it's not necessarily transmission-related - being a '91 truck you should have the Borg-Warner model # 1356 t-case that's well known for its self-destructive tendency of spinning the oil pump after wearing thru its keeper at higher mileage - unfortunately the only way to check for that is by taking the case out and apart, it's not a hard job but it's not for the faint of heart either... Again a stethoscope would make your task of identifying it as a possible problem much easier.

 

[OLDBULL8]

To all who provide so much info, thanks. Went and got some new bolts after my last post, the ones that were on there were rounded over, very tight and hard time getting them off. Couldnt find any bolts with the built in flange so picked up regular bolts and washers. Think I am messing up the pictures when I put them up... will try again.

You might just have created a problem. By the way, those are nuts, not bolts. Any Ford dealer or trans shop has the correct NUTS, They are an actually a one time use nut. You made a mistake by removing the original nuts. You where told to just check for tight. If you notice the original nuts are kind of rounded on one side and are a SPECIAL nut called an "interference nut" where one or two threads are like crushed. I advise you get the correct nuts and install them.There is little difference between a 14mm and a 13mm socket, a 14mm socket will be kind of loose on the correct nuts, a 13mm socket is a tight fit on the correct nut. If you can't find the correct nuts, at least romove the ones you got and then use some BLUE LOCTITE on the BOLT threads, just a drop will do. Lesson learned.

 

[OLDBULL8]

AND YEAH, there are a bunch of IDIOTS that like to post a lot of MISINFORMATION on YOUTUBE.

 

[LCAM-01XA]

I think he had a problem with the bolts for the dust cover and that is what he replaced, not the converter nuts?

 

[OLDBULL8]

Looks to me like nuts and washers in his last pic. He should confirm that they are or not. If there not new, then he can disregard my post about them.

 

[LCAM-01XA]

Nope, you're looking at your typical flanged all-steel locknuts there, no washers - see how it's tapered on the end that is away from the "washer"?

 

[davlun]

Sorry for the delay in getting back to you. Two very long work days, but say the notes and wanted to get back to both of you. I bought new bolts for the inspection cover, not the flex plate. They were so tight and rounded off that I had to get a tool to back them out.

I think you already answered my question as to complexity, but in my head, I was looking at those 4 bolts in the flex plate and was wondering how conceivable it would be to undo them all and then turn the engine on. With the trans disengaged seemed like it would be easy to figure out if it was making noise, or the engine... and only those 4 bolts holding things together. That seemed like so little but it must be the way things work and how they are put together.

To continue on, I am going to order a stethoscope from amazon, they seem to have a good selection of cheap ones and a couple have a lot of good reviews.

Will try and convey more information once I have it, perhaps I can record the audio from the stethoscope... going to hit the sack now. Thanks.

 

[LCAM-01XA]

I think you already answered my question as to complexity, but in my head, I was looking at those 4 bolts in the flex plate and was wondering how conceivable it would be to undo them all and then turn the engine on. With the trans disengaged seemed like it would be easy to figure out if it was making noise, or the engine... and only those 4 bolts holding things together. That seemed like so little but it must be the way things work and how they are put together.

Don't even think of touching those four nuts for the converter and then staring the engine! For one thing the studs are welded to the converter, this is not a GM product with nuts welded the converter and bolts going in from the front - Ford in their infinite wisdom did just the opposite and used studs coming in from the back and nuts on the front, this makes it somewhat annoying to install engines and transmission as the converter will not slide back enough for said studs to clear the flexplate and thus the flexplate holes need to be aligned with the converter studs upon mating engine and transmission or else bad things happen. So what that means to you is that even if you undo the four nuts and push the converter back as far as it will go the studs will still stick thru the flexplate some, thus firing up the engine will still turn the converter. Only now the converter will be free to bang around, and possibly not have its nose supported by the crank pilot hole - good way to wallow out the flexplate holes and possibly shear the converter studs at the very least, maybe even wipe out the transmission pump in the process.

 

[davlun]

Hello all, just wanted to post an update on this which was the original thread on this. So been plugging away at fixing various things. So the other day I was looking at the windshield chrome trim, have been having a bit of water come in car when it rains and wanted to try and find out from where. In the process found the water vent cover (really don't know what it is called, cowling maybe?) was loose and could easily be vibrating. So I stuffed some kleenex in it and went for a drive, rattle is greatly reduced. Got a bigger piece and some improvement, but something else seems to be loose somewhere below this top piece. Here is the video:
https://www.youtube.com/watch?v=xzu349YpBeo where you can see it, on drivers side.

Thoughts on how to proceed to address issue?