So I suppose after 3 Challengers and 65,000+ miles on the current 2012 392 Challenger SRT, it's about time to go through engine problems/diagnosis.
Background - daily driven vehicle, no major issues; initially starting with a clunky transmission issue, almost as if there was a warped portion in driveshaft. Then engine knocking occurred as if a bad tank of gas went through. Knocking is still persisting. Occasional clunking in the bottom by crankshaft, more noticeable when the car is facing downhill or up on ramps.
While MDS is on, it sounds like a musical instrument drum roll (video of sound below).
Symptoms -
- while idle, car leaning downhill, in gear - engine crankshaft, transmission, driveshaft wobbles excessively and occasionally, repetitively clunks; feels as if the crankshaft is loose or there is a part that is warped causing the crankshaft to wobble. Visually inspecting underneath the car, with the belly pan off, the crankshaft pulley/harmonic balancer has about a 1/2inch or less wobbly play with the engine on; the belt tensioner shakes intermittently when the crank occasionally clunks. With a hand on the oil pan, you can feel the interment clunks shaking the engine.
- while driving, in manual or auto mode, easy acceleration in any gear results in a rpm dependent metallic clacking sound coming from center to low center of the engine, possibly between engine and transmission. The noise in city driving is mostly occurring between 1500-2000rpm.
- while driving highway, spurts of moderate to light acceleration results in metallic clanking/knock. The issue is amplified when MDS (fuel saver) kicks on, again clanking/knock noise while cruising 45-55mph (it sounds like a drum roll). On hard acceleration, there is no audible noise, however, during transmission shifts, initially for 1-2seconds upon completion of the gear change, the metallic clanking/knock occurs and then subsides. Also, light ease in-out of the accelerator, the clank/knock occurs and can be heard persistently.
So far,
The car has been to the dealership with the following diagnosis:
- overall dealership diagnosis: "had 4 technicians look at it and could not find anything mechanically wrong, probably just some spark knock"
- possible spark/fuel knock
- had a fuel treatment run through, knock was a little less, however metallic clank/knock is still there in the above mentioned symptoms
- recommend running a few tanks of gas
- supposedly did a compression/misfire test
-no engine codes
-says the crank pulley is ok even with the slight wobble
So far,
-I've run 3 tanks of gas through along with a Lucas Fuel Treatment: pure 91 octane through, 93 octane with ethanol
-I did a datalog with the stock tune and on certain points of acceleration seeking 6-7 ST Knock both short and Long. I think this is partially amplified because of mechanical knock somewhere from within the oil pan / connection with transmission.
-When the engine is cold, there isn't much noise at all. Once the engine gets above 180 deg and to operating temperature around 200+ deg, the knock, shake and clatter are fairly persistent.
I'm still leaning towards a crankshaft issue/harmonic balancer, timing chain issue, flex plate, valve knock, dirty fuel injector, spark plug replacement, but wanted to get forum feedback first. (will check sparks and injectors his weekend)
I am thinking that the Dodge service techs know there is an issue internally with the drivetrain, however, are waiting until it gets worse before they start turning wrenches
Thanks for your help and responses.
An update from today.
-Spark plugs and fuel injectors seem all ok from visual inspection with no unusual noise that sounds like the noise from the drum roll video.
The noise:
-The noise only occurs while the car is in Drive or Reverse. When in park or neutral, there is no noise when revving the engine.
-The noise is RPM dependent; as in the noise is consistent with knocking/clacking faster or slower depending upon how fast the engine is revving
-The noise occurs on light to moderate load on the engine.
-Occurs with MDS on or off; more prominent when MDS is on
-Occurs when in manual or auto transmission modes
-With the emergency brake on and car in gear, I can replicate the noise with the car staying still.
My guess right now is that is seems like something loose between engine and transmission.
-Pulled the transmission inspection plate off to peak at the flex plate. Didn't see any cracks or wear.
Interesting part now is that the knock is very prominent on any acceleration and constant load. If you get in to the engine hard, the knock goes away. If you're foot is out of the accelerator pedal and the car is coasting, there is no knock.
None the less, I don't think this is spark knock as the dealership has diagnosed...
Looks like back to the dealership Monday...
Here is the crank pulley video. The wobble is probably 1/4in give or less (visible by the shadow). I think the wobble is not actually the crank pulley because when I had the drivebelt off, there was no play in it. Even then, he dealer service tech, after viewing the video, says this is normal.
Took the vehicle out down the block for more testing.
I think the service department is not noticing the issue because the engine has to be warmed up/operating temperature before it gets really noticeable.
I did escalate the issue up through Chrysler Customer Service and got a case number from SRT to do a follow up on the issue so that hopefully Monday won't be "we couldn't find anything wrong / everything is in mechanical working order / it's just spark knock".
Diagnosis Update 11/10/2014 -
So the results of the Service Department diagnosis is bad lifters and a new battery (battery not part of the issue, however, it was just its time to be changed). They had to let the car sit idle for about 15-20 minutes before taking it on a test drive to warm up. Initially during their test drive, they didn't hear it but once they got going, it was really loud. They brought it back in the shop and even one of the mechanics said, "there's your noise" to the other tech
Also got a Misfire Code on cylinder #3 eventually.
I brought the car back home, listened for myself with a mechanic stethoscope and it sounds like the noise is coming from around cylinder #5 on the driver's side.
For reference, when MDS (fuel saver mode) occurs, cylinders 1-4-6-7 (red in the photo) shut down and 2-3-5-8 (yellow in the photo) continue to fire.
Parts are inbound and we'll see what happens after the installation. My gut still tells me there is more to this than just the lifters though.
Was also researching a bit from another forum. Spun Rod or Bad Lifter
Also got a call from SRT Customer Service. They mentioned that, since parts are ordered, to let this dealership do the service work. If not satisfied, they would send me to an SRT performance dealership. They also reassured that this would be covered under the Powertrain Warranty.
Final Diagnosis/Resolution 12/3/2014 -
I picked up the car today with all the warranty repairs conducted. Below is a summary of the final tech sheet:
"Customer states clunk noise from engine. Noticed while under vehicle that the harmonic balancer and tensioner pulley has excessive amount of movement. Tear down and found lifter damage. Cam Lobe on NO #3 damaged. Replaced Camshaft and Lifters"
Parts changed out:
-Lifters
-Head gaskets
-Camshaft
-Engine oil filter
-Oil 5w-40
-Antifreeze
Background - daily driven vehicle, no major issues; initially starting with a clunky transmission issue, almost as if there was a warped portion in driveshaft. Then engine knocking occurred as if a bad tank of gas went through. Knocking is still persisting. Occasional clunking in the bottom by crankshaft, more noticeable when the car is facing downhill or up on ramps.
While MDS is on, it sounds like a musical instrument drum roll (video of sound below).
Symptoms -
- while idle, car leaning downhill, in gear - engine crankshaft, transmission, driveshaft wobbles excessively and occasionally, repetitively clunks; feels as if the crankshaft is loose or there is a part that is warped causing the crankshaft to wobble. Visually inspecting underneath the car, with the belly pan off, the crankshaft pulley/harmonic balancer has about a 1/2inch or less wobbly play with the engine on; the belt tensioner shakes intermittently when the crank occasionally clunks. With a hand on the oil pan, you can feel the interment clunks shaking the engine.
- while driving, in manual or auto mode, easy acceleration in any gear results in a rpm dependent metallic clacking sound coming from center to low center of the engine, possibly between engine and transmission. The noise in city driving is mostly occurring between 1500-2000rpm.
- while driving highway, spurts of moderate to light acceleration results in metallic clanking/knock. The issue is amplified when MDS (fuel saver) kicks on, again clanking/knock noise while cruising 45-55mph (it sounds like a drum roll). On hard acceleration, there is no audible noise, however, during transmission shifts, initially for 1-2seconds upon completion of the gear change, the metallic clanking/knock occurs and then subsides. Also, light ease in-out of the accelerator, the clank/knock occurs and can be heard persistently.
So far,
The car has been to the dealership with the following diagnosis:
- overall dealership diagnosis: "had 4 technicians look at it and could not find anything mechanically wrong, probably just some spark knock"
- possible spark/fuel knock
- had a fuel treatment run through, knock was a little less, however metallic clank/knock is still there in the above mentioned symptoms
- recommend running a few tanks of gas
- supposedly did a compression/misfire test
-no engine codes
-says the crank pulley is ok even with the slight wobble
So far,
-I've run 3 tanks of gas through along with a Lucas Fuel Treatment: pure 91 octane through, 93 octane with ethanol
-I did a datalog with the stock tune and on certain points of acceleration seeking 6-7 ST Knock both short and Long. I think this is partially amplified because of mechanical knock somewhere from within the oil pan / connection with transmission.
-When the engine is cold, there isn't much noise at all. Once the engine gets above 180 deg and to operating temperature around 200+ deg, the knock, shake and clatter are fairly persistent.
I'm still leaning towards a crankshaft issue/harmonic balancer, timing chain issue, flex plate, valve knock, dirty fuel injector, spark plug replacement, but wanted to get forum feedback first. (will check sparks and injectors his weekend)
I am thinking that the Dodge service techs know there is an issue internally with the drivetrain, however, are waiting until it gets worse before they start turning wrenches
Thanks for your help and responses.
An update from today.
-Spark plugs and fuel injectors seem all ok from visual inspection with no unusual noise that sounds like the noise from the drum roll video.
The noise:
-The noise only occurs while the car is in Drive or Reverse. When in park or neutral, there is no noise when revving the engine.
-The noise is RPM dependent; as in the noise is consistent with knocking/clacking faster or slower depending upon how fast the engine is revving
-The noise occurs on light to moderate load on the engine.
-Occurs with MDS on or off; more prominent when MDS is on
-Occurs when in manual or auto transmission modes
-With the emergency brake on and car in gear, I can replicate the noise with the car staying still.
My guess right now is that is seems like something loose between engine and transmission.
-Pulled the transmission inspection plate off to peak at the flex plate. Didn't see any cracks or wear.
Interesting part now is that the knock is very prominent on any acceleration and constant load. If you get in to the engine hard, the knock goes away. If you're foot is out of the accelerator pedal and the car is coasting, there is no knock.
None the less, I don't think this is spark knock as the dealership has diagnosed...
Looks like back to the dealership Monday...
Here is the crank pulley video. The wobble is probably 1/4in give or less (visible by the shadow). I think the wobble is not actually the crank pulley because when I had the drivebelt off, there was no play in it. Even then, he dealer service tech, after viewing the video, says this is normal.
Took the vehicle out down the block for more testing.
I think the service department is not noticing the issue because the engine has to be warmed up/operating temperature before it gets really noticeable.
I did escalate the issue up through Chrysler Customer Service and got a case number from SRT to do a follow up on the issue so that hopefully Monday won't be "we couldn't find anything wrong / everything is in mechanical working order / it's just spark knock".
Diagnosis Update 11/10/2014 -
So the results of the Service Department diagnosis is bad lifters and a new battery (battery not part of the issue, however, it was just its time to be changed). They had to let the car sit idle for about 15-20 minutes before taking it on a test drive to warm up. Initially during their test drive, they didn't hear it but once they got going, it was really loud. They brought it back in the shop and even one of the mechanics said, "there's your noise" to the other tech
Also got a Misfire Code on cylinder #3 eventually.
I brought the car back home, listened for myself with a mechanic stethoscope and it sounds like the noise is coming from around cylinder #5 on the driver's side.
For reference, when MDS (fuel saver mode) occurs, cylinders 1-4-6-7 (red in the photo) shut down and 2-3-5-8 (yellow in the photo) continue to fire.
Parts are inbound and we'll see what happens after the installation. My gut still tells me there is more to this than just the lifters though.
Was also researching a bit from another forum. Spun Rod or Bad Lifter
Also got a call from SRT Customer Service. They mentioned that, since parts are ordered, to let this dealership do the service work. If not satisfied, they would send me to an SRT performance dealership. They also reassured that this would be covered under the Powertrain Warranty.
Final Diagnosis/Resolution 12/3/2014 -
I picked up the car today with all the warranty repairs conducted. Below is a summary of the final tech sheet:
"Customer states clunk noise from engine. Noticed while under vehicle that the harmonic balancer and tensioner pulley has excessive amount of movement. Tear down and found lifter damage. Cam Lobe on NO #3 damaged. Replaced Camshaft and Lifters"
Parts changed out:
-Lifters
-Head gaskets
-Camshaft
-Engine oil filter
-Oil 5w-40
-Antifreeze