Broke Down South Bound Can't find the problem. 11 day's in.

[Enigmatic Nomadics]

1996 T444e 175hp partnered with AT545 on a 3600 Thomas vista chassis. 308k miles on everything.

Coming around a slow, flat curve, pulling a trailer on the interstate a clatter started from the engine/transmission area. I pulled over immediately to look things over and this is what I THINK I have ruled out so far:

Turbo- Removed the hoses and it is dry inside and doesn't have any play.

Removed the serpentine belt and found nothing loose. The fan clutch feels strong, all pulleys feel tight. The clatter remains with motor running and belt removed.

Injectors seem okay-Using a laser thermometer, all the cylinders seem to be registering the same temps while the motor is at idle.

I purchased a Scangauge D and ran through a diagnostics test and no codes are displayed.

So I find a youtube video that has a sound a lot like my problem and the video claims the flex plate is broken as the problem therefore I make the decision to separate the transmission from the motor and inspect the flex plate.

Here is that video:

https://www.youtube.com/watch?v=-Ee5G5P17xM

After removing the part and inspecting it, I learn that my skoolie does NOT have a flex plate but something far more robust. More of a flywheel. It must weigh in the neighborhood of 35lbs and is in very good condition.

I am now reinstalling the flywheel and ancillary parts associates with it and will start the motor without the transmission attaches to see if I learn anything meaningful but basically I'm stumped at this point.

No unusual smoke coming from the exhaust to report.

I appreciate any suggestions as to what should be ruled out next. I've been here 11 days now and everybody is being super cool but it's time to move on.

A shop rescue is cost prohibitive.

Also, I want to get this out to anyone reading this:

I have been all over the bus's undercarriage for more than a week now and seen everything from all angles and I'd like to pass on that I found 5 significant bare wire wear spots so far that I will be cleaning and coating with JB weld then covering with fresh loom. some are heavy gauge wires going to the starter and some are sensor wiring going into the transmission. I would expect all older bus's may display the same wear issues and would benefit from an inspection.


Thanks,


~Jamie

[magnakansas]

do you think noise was road speed dependent, or engine speed dependent.

answer with first impression.

engine speed dependent the looking at front part of the transmission forward

road speed dependent looking at rear of transmission back to axle, front wheels/brakes... things that go round and round

hope this gives an idea

william

[cadillackid]

did you start the engine with the transmission removed? did the sound stick with the engine or did it stop with the transmission off (and flywheel still attached).. its really hard for me to diagnose something I cant hear



did you start the engine with the serp belt removed? (EDIT just saw you did this)


clattering noises on a T444E often relate to an HPOP that is about to go on the skids.. and also injector noise if the Lift pressure ends up low... all those plungers bottom out.. you'll notice loss of power in that case..



again running the engine for short periods with parts removed(toroque converter backed off,, serp belt removed) is good way to isolate the issue..

[Enigmatic Nomadics]

Thanks William.


Definitely not road speed dependent but I can't say with 100% certainty the throttle has any affect. The noise seems sporadically unrelated to either.


I should mention that the motor seemed like it was missing when I would 'give it gas' a little while parked. I have to wonder if I've misdiagnosed a fuel injector problem but I would think taking the motor up to 125 degrees F would be enough to conduct the temperature check.

[Enigmatic Nomadics]

Thanks CK,


My next move is to reinstall the flywheel and battery's and try listening to the motor without the tranny bolted to it. I may get rained out today based on the weather so far.


I thought about draining the HPOP and replacing the oil but haven't done so. You sound like you know a lot more about these things than I do.


I'll report back once I hear the motor by it's self.

Also, as for the sound it is making. It's an awful lot like the sound in the video I attached to the original post.

Do you think I should drain/replace the oil in the HPOP?

[cadillackid]

the HPOP oil is the same oil as in the pan.. its in as reservoire but isnt a closed loop so no need to drain and refill it...



these engines also have hydraulic lifters.. in fact standard roller lifters very similar to what later model chevy engines used.. if your Lube oil pressure is low then lifters can go flat and rattle a lot.. id expect this to subside when the engine is cold.. so if the sound doesnt change with temperature we can likely rule out lifters..



a lot should be learned with running the engine trans removed.. be careful revving it up and down.. without the torque coverter weight it will rev up and down very quickly so I wouldnt try to redline it..



while you cant run it very long with the SERP belt off.. you can run it long enough to try and get a directional on your noise.. top, bottom, back, front.. sometimes a metal bar end rested against the engine and the other against your ear or near-ear area can net you some insight into where its coming from..


again running with the trans off is a good test.. do make sure you properly torque the flywheel bolts down.... id have to look up the torque spec but it involces blocking the crank from turning to tighten them properly.. those bolts WILL back out if not proper tight..



for the future.. the torque converter bolts / nuts require Loctite as they are in somewhat fragile bosses so the torque is somewhat "light"(25 ft lbs) on those and then they are loctited to not back off...



as for as what torque? seems to be discrepencies.. in my book (covers my 99.5) the flywheel bolts get torqued to 89 ft lbs... some people say on the earlier 444E it used smaller 3/8 bolts and only got torqued to 65... there may be a 94-96 444E service manual around here which would have your year for sure..

[BamaBus]

Originally Posted by cadillackid

as for as what torque? seems to be discrepencies.. in my book (covers my 99.5) the flywheel bolts get torqued to 89 ft lbs... some people say on the earlier 444E it used smaller 3/8 bolts and only got torqued to 65... there may be a 94-96 444E service manual around here which would have your year for sure..

EGES 120-1 for years 1994-1997 has the same 89 ft lbs.

[Enigmatic Nomadics]

Originally Posted by cadillackid

the HPOP oil is the same oil as in the pan.. its in as reservoire but isnt a closed loop so no need to drain and refill it...

I hear ya CK. I was going by this video b/c although replacing the oil may not solve the problem, It may fall under preventative. I'm still learning.

https://www.youtube.com/watch?v=u4Je9tsbXFY

That said, WOW you've given me a lot to still look into and I appreciate your taking the time. I just stopped for a sandwich and need to get back at it but thanks to you and everyone else chiming in. I'm trying to line up the flywheel to the motor as one man and that thing must weigh 50lbs. lol
I'm almost there though.

[Enigmatic Nomadics]

Got the flywheel back on and torqued to 90lbs. Took all day with a bottle jack and two ratchet straps dropped down from the dog house. Used the blue lock-tight b/c that's what I had.


Tomorrow I'll reconnect the starter batteries and fire it up for the first time in several days. I'm hoping tomorrow will be a big day of discovery.

[Enigmatic Nomadics]

Started the motor (Added a LI-BIM 225amp 15min on-20 min off coach battery charger while I was in the battery compartment)


and the clatter was immediate and remains constant. That's good news considering the transmission replacement cost but I still can't find the noise location.


Suggestions on the next course of action pls.

[magnakansas]

I am reminded about this ..... if a lifter has broken and is grinding away on the camshaft.... an engine oil drain should show lots of metal bits....

also .. cut open the engine oil filter and look for metal in the filter pleats

william

[Enigmatic Nomadics]

Would I not see evidence of that at the tail pipe when the motor is running, William? Just wondering and when I finally get this sorted, I'll definitely report back.

[Booyah45828]

Well, for starters your bus will have both flywheel and flexplate.

But, you seemed to have inspected that and determined it to be fine. You also ruled out the trans with your testing, pretty much leaving the engine alone as the culprit of the noise. A lot of failure points in one of those, some more probable then others. What's improbable is for one of us to diagnose what you're hearing without us being there, and it's nearly impossible for us to diagnose it without a video of the problem.

A lot of suggestions have been made as to your problem. A lot of them you won't figure out until you tear into it. Truthfully, you've eliminated a lot of the cheap solutions, and I get that you want to spend as little as possible here, but sometimes it's cheaper to let a pro fix it then an amateur to continually guess.

In all honesty, once you're at the point where it's internal engine damage, the odds of you fixing it are slim. I'm not certain where you're exactly at, but I've got a feeling an engine rebuild isn't likely in the cards.

[magnakansas]

Nope . I don’t think you can diagnose from tail pipe. Other people can . I think from what you have said and the tools at your disposal, I think the best way to see if you are grinding up the inside of your engine is to drain to a clean oil pan. Think like you are prospecting for those gold flakes. I have a hunch you have broken the insides of your engine.

If your engine oil is clean, then you can pour it back into the engine to keep cost low.

Cut open the filter….. there are many you tube videos on how to do this, but if you get junk when you drain the engine oil then you already know there is junk
William

[Enigmatic Nomadics]

I filmed the motor noise on video:
https://youtu.be/ds4GNqtNP4U
https://youtu.be/6ATJSNSRMR8

[sportyrick]

my vote is harmonic balancer! Or the crank broke in half!

[Jolly Roger bus 223]

can you drop the belt or belts and wiggle things around?
could be an idler pulley.
best case scenario.
also a piece of hose stuck down and around the area and to your ear like a stethoscope could help pin point an area.

[Enigmatic Nomadics]

I went into town and purchased a stethoscope and everything for an oil change so I can listen to the motor and inspect the oil and filter filament.


While warming up the motor for the oil change I tried the stethoscope for the first time and found a very notable noise consistent with the problem noise and it was most apparent from the valve cover on the drivers side.

[magnakansas]

How difficult is valve cover removal?

William

[Enigmatic Nomadics]

I don't know yet William, but I'll report back. I'll also do a video of the oil inside the filter element and drain pan.



BTW, I still have the tranny out and the torque converter hasn't been reinstalled and I'm finding more bare wire wear spots that will have to be coated with JB Weld and given a fresh layer of loom. I plan to suspend these wires, hosed and cables way better than factory by the time that part is buttoned up.