i am having an issue with the ol ram that has had me and several other professional mechanics scratching our heads for some time now... the fam and i took a trip to south carolina and on the way back i noticed a knocking noise coming from under the truck. i stopped to check it out but could not find anything obviously wrong. i continued to drive home apx 70 miles. the temp gauge never went up oil preesure was normal no loss in power shifted and drove normally except loud noise of corse. changed oil no metal shavings. the noise sounds like a nut or bolt bouncing around in the bell housing of tranny. stuck a stethascope on the engine block right in front of tranny and could not hear the noise, moved back to bell housing and could hear it plain as day.the farther back i went on the tranny the quieter the noise got. pulled the tranny out and found everything to appear normal. replaced flex plate and torque converter and still nothing has changed. at idle the noise comes and goes but gets louder whenu give it gas. if any one has any suggestions or thoughts they would be very much appreciated! thanks in advance guys
variable knocking/ tapping noise from tanny?
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Is this a regular, rhythmic knocking (that goes with engine speed), or a random knocking? You didn't see any contact / damage between the converter and transmission pump cover, or between converter bolts and back of block or trans dust cover? No cracks in the flexplate?
its more of a random knock. like i said it sounds sort of a like a bolt bouncing around but i saw no evidence of any contact. the flex plate did not have any scrapes or markings nor the torque converter. the front pump cover was clean as a whistle and the retaining clip was still in place. all torque converter bolts were in flexplate and tight. i had a mechanic that worked at a local dodge dealer for several years helping me and he thought the flexplate was cracked by the sound, but it and converter have been replaced and still same noise. the only thing i notice that may or may not be normal is the converter had play in it top to bottom and side to side apx 1/4 in both ways when it was on the shaft and spun back all the way. we also tried unbolting converter from flywheel and starting and still had noise but noticed that converter was still spinning. why, i do not know. checked 3 times to make sure converter was all the way back. like i said its stumped a few of us ( not tranny guys) and im leary of paying dealer 80$ an hour to try every thing i have already done so was hoping some one who knew more about trannys could give me some more ideas.
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The converter has a snout in the front that pilots into a bore in the crankshaft, so that is likely what was driving it (when you had the engine running with the converter pushed back).
Does the knock happen in all gears (Park, Neutral, Drive, Reverse) when at a stop?
Does the knock happen in all gears (Park, Neutral, Drive, Reverse) when at a stop?
makes perfect sense why it still spins. the knocking did decrese slightly when bolts were out of converter tho. yes does it at all times but the knocking speed slows down when in gear with brake applied and no throttle. noise does not change in any other way otherwise. had a guy tell me that the front pump bushing could be bad but to me ( an this is just my thinking ) if the bushing went out, and driving that far after the fact it wouldnt have held up or at least would have some shavings or some type of foreign matter in tranny fluid or pan ect... but then again i have been wrong before
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Well, it can't be the trans input shaft (or anything further back) since that's not turning at a stop in Drive. Has to be engine, converter, or trans pump. Since the converter has been replaced, I doubt that's the problem. A knocking noise would be unusual for the trans pump. Maybe a bad rod bearing or piston pin in the engine?
I'm no engine expert, but could you maybe disconnect the fuel injectors or spark plugs (one at a time) to try to find a bad cylinder? If the knock is due to the firing stroke (banging the piston against a loose pin or rod bearing) then maybe deactivating that cylinder would eliminate the noise (and thus, show where the problem is). Just a thought...
Do you have MDS? If so, does it still knock in MDS mode?
I'm no engine expert, but could you maybe disconnect the fuel injectors or spark plugs (one at a time) to try to find a bad cylinder? If the knock is due to the firing stroke (banging the piston against a loose pin or rod bearing) then maybe deactivating that cylinder would eliminate the noise (and thus, show where the problem is). Just a thought...
Do you have MDS? If so, does it still knock in MDS mode?
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Sorry to butt in...just following the thread...no MDS on a 2004. I don't believe that started until 2006.
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No need to apologize! Thanks for the info! Not being an engine guy, I'm not intimately familiar with MDS details.....
i could definatly try that. at this point im not ruling anything out on theory alone. the only reason i did not think it was in the engine was driving 70 miles at apx 50 - 60 mph with a bad rod or bearing anywhere in the engine that it would have failed to maintain proper temp and oil pressure and most of all proper function or without at least giving me some type of evidence in the oil. but said it before and il say it again i have been wrong before. i will definatly give it a try before i send it off to the dealer and let them rack their brains for 80$ an hour. if it was only still under warranty..... haha oh well. thanks transengineer for all your thoughts and help i will post updates on how it goes... that is, considering i can still afford to keep the internet service on lol
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MDS = Multi-Displacement System, where the engine cuts back to operate on only 4 cylinders during cruise conditions (to conserve fuel).
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Check your exhaust manifold bolts. They are notorious for breaking and tapping just like you described. Due to the mani location, it would be easy to mistake it for a noise under the truck. It sounds like you've inspected everything trans wise already so check those bolts.
I sure hope brik12210 updates us soon. I have a 2005 Ram 2500 4x4 Quad that seems to be doing the same thing. I pulled the tc cover and inspected my tc bolts. Everything looked good. The noise did seem louder when I ran it with the cover off. I could also feel the knocking on the trans pan. I figured that was he source so I took my truck to trans shop. The are insisting it's not the transmission but the engine. They apparently unbolted the flywheel from the torque converter and pushed back the torque converter and since the noise was still present they are saying its not the transmission. It did not make sense to me since they obviously were still spinning the transmission, like brik12210 noted above, trans will still spin on shaft.
Where should I look for this exhaust leak or broken bolts? I checked manf to exhaust pipe connections, they look good. But access to manifold bolts seems tight. Should I focus on back end of manifolds or all around. Heat shield seems to block most of my view. Am I looking for a leak or a missing bolt?
What makes this difficult is that there is no cels for knock sensor nor exhaust leak. Also truck seems to continue running fine except for the loud nonstop knocking. Knocking incereases with rpms.
Thanks in advance for everyone's input.
Where should I look for this exhaust leak or broken bolts? I checked manf to exhaust pipe connections, they look good. But access to manifold bolts seems tight. Should I focus on back end of manifolds or all around. Heat shield seems to block most of my view. Am I looking for a leak or a missing bolt?
What makes this difficult is that there is no cels for knock sensor nor exhaust leak. Also truck seems to continue running fine except for the loud nonstop knocking. Knocking incereases with rpms.
Thanks in advance for everyone's input.
I would like to clarify that the knocking I have is constant but increases with rpms and does it in every gear but does quite down some while stopped at a light. This knocking is loud and more like a banging. Much louder than any diesel truck knocking. Almost like a bolt hitting moving metal at every rev. I too narrowed it down to the tc and bell housing. But, could be coming from anywhere near this area. I will check exhaust manifolds but from what I have search sounds like exhaust manifold bolts breaking is common but is not necessarily associated with this constant knocking. Also, I don't have the traditional exhaust leak noise or roar.
Also, I was able to drive it home some 65 miles going 60 mph and everything worked fine, no hesitation, no smoking, no shifting issues, no cel, no overheating, and no oil pressure issues.
How can I rule out rod or bearing? Should the disconnecting wire connectors at each plug/cylinder work?
Any suggestions or input?
Also, I was able to drive it home some 65 miles going 60 mph and everything worked fine, no hesitation, no smoking, no shifting issues, no cel, no overheating, and no oil pressure issues.
How can I rule out rod or bearing? Should the disconnecting wire connectors at each plug/cylinder work?
Any suggestions or input?
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Multiple Displacement System. It will shut down fuel to four of the cylinders during no or light engine load such as highway driving to get better fuel mileage.
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I have a 2011 Ram 1500 that went to the dealership for camd and Lifters came back to be with a broken bellhousing so had to buy a transmission, when it came back to me it had tgis same exact knocking noice and a metal to metal scratching sound that cannot be located. New transmission I had to buy, also replaced the flex plate/flywheel. However, I have pulled all coil packs individual and no change in knocking noise, My truck will nit go back to the dealership, after damage to the outside of the truck, damage to the inside of my truck and also having to buy a new transmission due to them replacing a brand new starter on the truck that was not authorized by me or the warranty company. Now my 2011 Ram is sitting in the driveway wasting away. Does anyone know how to figure out where this knocking noise is coming from without the transmission being hooked up? It would be nice to know if it was in my engine. I also fid locate one main bolt the dealership had broken. Please help
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