My '90 is sick, bad noises cometh from it

[Wwalden]

Hey folks,



It just started the other day, when I let off the throttle or put the transmission in neutral, at idle, there is a horrible noise that sounds like someone shaking a big rock in a big coffee can. It sounds like when a gasoline engine "diesels" but this is more of a metallic sound. It doesn't do it all the time, in fact on the way to work this morning it didn't do it at all, but then it will just start up, and its LOUD. It sounds like the engine is over with, just going to fly apart at any second. But then, it will sound normal again and not do it for a while.



Even when it does do it, when I bring the RPMs up, and during normal highway driving it's fine, and the power is fine, no loss there. This is really starting to scare me so I thought I'd post before I call around to get this in the shop.



She just passed 200,000 miles and this sort of kept me from being too excited about it.



Please help, I can try and email a sound file to those who would be interested.



Thanks very much



Wes

 

[paccool]

Wes,



you ned to get your profile filed out a little more. Is the truck an automatic or manual transmission? If auto, check the torque converter bolts. Could be a bad converter. The first thought that came to mind was the KDP struck again. Being intermitent, I'm not sure if that could be it or not.



Can you tell from what area in the engine the noise is coming from?

 

[Bluebird]

transmission noise?

My truck has made a similar noise for awhile now. Comes and goes, I usually hear it when the trucks shifts into third. All performance is normal, just a rattling type sound (medium to higher jingling pitch). Pulls fine, runs good, transmission fluid color=normal red/pink on white towel. Regular service, should I be concerned?

Patrick.

 

[jdurham]

Don't know if this helps, but mine did the same thing when I broke a flex plate. If yours is automatic, pull the inspection cover off of the front of the transmission and see if the flex plate is broken. When I pulled mine, parts of the flex plate fell out!:--)



Hope this helps...



Jim

 

[BushWakr - RIP]

It's quite possible you've broken the flex plate as the guys have mentioned.

If it is the KDP you'll very likely have at least SOME oil loss at the front of the engine, and if it's really done damage, you'll have big puddles ... ... until the oil is all gone... but you'd notice that pretty much right away.



Bob.

 

[paccool]

Hey Bush, do you think it could be the KDP? I was wondering if becqause it was intermittent that it probably isn't the pin. Then I thought that maybe the pin was trying to come out and when it hit the gear it was being pused back in. Can the pin come all the way out of the hole before it hits the gear?



Stan

 

[R.E. Miller]

Could be a bad injector causing a horrendous fuel knock. N-14's sound like they are just going to blow when the injector solenoid gets hung wide open.

Russell

 

[boatpuller]

Mine sounded just like that about 50 miles before the center ripped out of the flex plate, when the noise started I pulled the cover under the torque converter and could just barely see some cracks in the flexplate, no pieces fell out but within 50-60 miles it let go.

Good Luck,

Caleb

 

[Bob Beauchaine]

As far as the KDP goes check the front of the engine you should see oil leaking - as in heavy from the passangers side front of the engine. Look behind and below the fan mount. When they go it is usually there.



Stan - the dowel pin has to fall out completely before it hits anything. If it drops to the pass side it will probably crack the front case - minium. If it goes the other way it could grenade the engine.



It sounds like you have a cracked or broken flex plate. That would be my first guess. Good luck.



Bob

 

[paccool]

GOTTA GET MINE FIXED!!! Sure wouldn't want to rebuild the thing. Maybe after the trip to Piers cause I won't have time before.



Stan

 

[Wwalden]

Update

I'm sorry I didn't provide details, my profiles are never up to date. The truck does have the 3 speed automatic.



Thanks very much to all for the replies. I will be checking the flexplate tommorow, when I crawl under it and pull the inspection cover off. I was hoping it wasn't transmission related, but I suppose of anything the flexplate isn't too bad if caught early.



The noise sounds like it is coming from the rear of the engine, but it's too loud to pinpoint.



The update is, the trips to work and back since I first posted, which are about 25 miles each way, have been noise free. No knocking/rattling of any kind, out of the ordinary that is, which is quite loud!



I don't understand how it could be making that much noise if it's just a crack in the flexplate. If it's broken, could it "hang" back up correctly and operate quietly? I'll find out tommorow.



One interesting thing, concerning the idea about the stuck injector. If it is fuel related, then could it be a bad batch of fuel would cause such a sound? I did get the last tank from a station I don't usually stop in, near my work. I let the tank run down and put a fresh batch of a different brand fuel in it the same day I posted, which has sort of coincided with the noise ceasing.



Thanks very much again,



Wes

 

[jdurham]

don't understand how it could be making that much noise if it's just a crack in the

I don't know either, but that is exactly what my 90 did when i lost my flexplate. See if the torque convertor can be slid back away from the flexplate, they break near the center. Also, make sure you buy the new flex plate from Cummins, not dodge. I got burned when I did minebecause the dealer was MUCH higher priced than Cummins.



The following is what happened when I ordered mine, along with part numbers and prices...



Dealer said $295, told them I wanted Chrysler employee discount, they told me $221. Ordered it. It came in in a Cummins box, with a Cummins part number. Called Cummins, price was $94. 22



Anyway, here are the part numbers so you guys don't have to take the same beating I took...



FLEX PLATE 1995 Cummins



Chrysler Part # 5015709 Price $295. 00

Cummins Part #3946161 Price $ 94. 22



Hope this helps...



Jim

 

[jdurham]

Oh I forgot, the 95 fits our trucks but is supposedly a little stronger...

 

[Paychk]

Link to the 95 data:



https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=77138

 

["Mad Max"]

Agree it could be flexplate

Wes, the flexplate could make that kind of noise. The crank, plate, converter, etc all shift forward and backwards, just a little, based on how much end play there is inbetween the crank journals and the bearings. But even that litle bit can cause the flexplate to flex and eventually 'rip', and ultimately fail.

When you mentioned that it comes and goes when you shift into neutral and back into gear sounds like it COULD be the flexplate. Fortunately it's a relatively simple fix, at least for a 2x4. 4x4 just has heavier stuff attached.

I wouldn't think a flexplate could fail either, but if it does it'll make all kinds of racket, and with the power going through it and the tolerances between a crack it'd sound like a flywheel coming apart inside a bellhousing.

If it was engine and making that much sound, I would think you'd have either cracked a rod or piston or blown a KDP or something permanent. I think that's the key, that it is intermitent.

Keep us posted, and good luck!

Just my thoughts. -

- Sam

 

[Bluebird]

Anyone change a flexplate?

Anyone change a flexplate? Do you know what pages in the Chrysler Manual give details? What advice or precautions are in order? I guess the transmission has to come out... Thanks for any input, Patrick

 

[RDusch]

It is possible to change if you remove rear drive shaft and linkage and slide trans back, about 4" gives you enough room to work, just make sure the torque converter stays with the trans .



Rick

 

[boatpuller]

Rick,

Do you think there is enough room to pull the rear seal holder out by moving the transmission back 4" like you suggest for the flexplate?

My rear seals leaking and it would be cool not to have to pull the transmission and transfer case completely out.



Thanks,

Caleb

 

[RDusch]

Once i had the flex plate out i had plenty of room to work up on the rear of the engine, i took a die grinder and cleaned up where the plate had dug into the block, i'm no sure how the seals come out but it would be worth a shot ... ... ..... Rick

 

[Wwalden]

UPDATE: FIXED!

Thanks very much again for all the replies. You guys who said it was the flexplate were exactly right. In fact, I just recently noticed in the new TDR that arrived in the mail there was a section in the 1st Gen that addressed this very problem.



Anyway, I bought the '95 flexplate from Cummins Parts counter and then took the truck to a local transmission shop to have it replaced. $290 plus $120 for the flexplate. The old flexplate was completely ripped in two, in a perfect circle, right outside the bolt pattern. It had "jammed" itself inside the seperated outer ring and thats why it had stopped for a while. It could have been a disaster, so I thank you for your help.



Now a proper 200,000 mile celebration can begin, and I look forward to 300k! (well, 250k will be quite a milestone to be fair).



Wes



'90 D250