Injector replacement didn't solve my issue, thoughts?

[Tanker93]

(01-25-2017 )Magard Wrote:  I'm glad you stayed with injectors instead of going crazy and pulling the head. Sometimes it's hard to stay with the simple things first. Listening to all of this I was wondering if a crank or cam sensor could give you fits like this. Just wondering for educational purposes. Glad it's seems to be fixed.

I just read this entire thing for the first time wondering if it was going to be a cam/crank sensor as ive had a faulty crank sensor create a slight miss when engine was under load! Pretty sure it wouldve thrown a code though..

[Hammerhead]

It sounds like a miss, but it now has 6 reman injectors and runs smooth as can be.
But the knock is still there. I've limped it home, and since it only does it above 1450 under load, I am putting it on the dyno this morning to see if I can narrow down where source is coming from.
Both snailexpress & DRISX came for test rides with me while I was chasing it thinking it was injectors and fuel related. They both agree this appears to be mechanical in nature.
Base timing (cams) has been confirmed to be correct.
Is there a way to "test" the crank position sensor, or must it be replaced to confirm?
I am under the impression that there are two crank position sensors, so if one fails the secondary can take over, but it will throw a code. When test driving we had Insite connected and these sensors had no issues noted in the data monitor.

[Rawze]

(01-31-2017 )Hammerhead Wrote:  It sounds like a miss, but it now has 6 reman injectors and runs smooth as can be.
But the knock is still there. I've limped it home, and since it only does it above 1450 under load, I am putting it on the dyno this morning to see if I can narrow down where source is coming from.
Both snailexpress & DRISX came for test rides with me while I was chasing it thinking it was injectors and fuel related. They both agree this appears to be mechanical in nature.
Base timing (cams) has been confirmed to be correct.
Is there a way to "test" the crank position sensor, or must it be replaced to confirm?
I am under the impression that there are two crank position sensors, so if one fails the secondary can take over, but it will throw a code. When test driving we had Insite connected and these sensors had no issues noted in the data monitor.

You might want to also ensure the tone wheel is not loose on the crank too. I mentioned it in my re-build series.

[Hammerhead]

Well, this ghost has finally been caught.
If I hadn't put my truck on the dyno, I would have continuously changed parts in an attempt to solve this issue. In fact, I was about to remove the problem part and put it back on unknowingly!
As soon as the dyno operator put about 300hp of resistance at 1550rpm the knock appeared. The shop foreman and I instantly turned to the front of the motor where the sounds was originating from. Gotcha, Crankshaft Damper!
I just replaced the damper in July, so I wouldn't have even thought of it?
My front crank seal just recently started to leak, and it was one of the things I was going to change while I was chasing this issue. Yup, that means I would have pulled the problem part off, not known it, and put it back on! It made no noise, and doesn't leak when we pulled it off. Changed it out, fired up the truck, we never even took it off the dyno, and started putting the power to it...nice, smooth, steady power, and no more knocking sound.
I've listened to Camstyn's clip in this http://rawze.com/forums/showthread.php?tid=1408 thread he started, and I'm fairly confident that his sound is the exact same as mine. He did his damper a couple months before I did mine, so he's comin by the shop tomorrow and we're gonna put my old OEM one on his to confirm it (it was changed in July, but didn't make noise it was replaced because it was at 600k).

[Rawze]

(01-31-2017 )Hammerhead Wrote:  Well, this ghost has finally been caught.
If I hadn't put my truck on the dyno, I would have continuously changed parts in an attempt to solve this issue. In fact, I was about to remove the problem part and put it back on unknowingly!
As soon as the dyno operator put about 300hp of resistance at 1550rpm the knock appeared. The shop foreman and I instantly turned to the front of the motor where the sounds was originating from. Gotcha, Crankshaft Damper!
I just replaced the damper in July, so I wouldn't have even thought of it?
My front crank seal just recently started to leak, and it was one of the things I was going to change while I was chasing this issue. Yup, that means I would have pulled the problem part off, not known it, and put it back on! It made no noise, and doesn't leak when we pulled it off. Changed it out, fired up the truck, we never even took it off the dyno, and started putting the power to it...nice, smooth, steady power, and no more knocking sound.
I've listened to Camstyn's clip in this http://rawze.com/forums/showthread.php?tid=1408 thread he started, and I'm fairly confident that his sound is the exact same as mine. He did his damper a couple months before I did mine, so he's comin by the shop tomorrow and we're gonna put my old OEM one on his to confirm it (it was changed in July, but didn't make noise it was replaced because it was at 600k).

Was the one that caused the trouble an OEM? or an after-market brand?

I haven't thought about it, but an unbalanced crank shaft damper could possibly also cause excess vibration to the crank tone wheel. That can in turn throw off the crank position sensor, making it run rougher and amplify the problem at certain rpms.

[Hammerhead]

(02-01-2017 )Rawze Wrote:  Was the one that caused the trouble an OEM? or an after-market brand?

I haven't thought about it, but an unbalanced crank shaft damper could possibly also cause excess vibration to the crank tone wheel. That can in turn throw off the crank position sensor, making it run rougher and amplify the problem at certain rpms.

Both Camstyn & I have Vibratech dampers. Since we changed ours at essentially the same time in Alberta, we are wondering if possibly Vibratech had a bad batch, or because there is no date code on them, that perhaps we ended up with old stock.
This is purely speculation, but I do know of several guys that have Vibratech dampers on for several years with no issues. The shop I did the dyno run at said they diagnose a damper failure with the dyno about once a year, with about an equal split OEM/AM and failures with this brand in Camstyn & I's short time frame rare.
I called my Vegas host and told him the results, and he agreed, he also ruled damper out because he saw that it was new. He said he's glad I limped it home and did the dyno run, because no Vegas shops have a dyno anymore and we would have ended up pulling the oil pan, front gear cover, compressor, and god knows what trying to chase it.

[Camstyn]

A little late but I've got an update.. Hammerhead was nice enough to let me use his OEM damper for troubleshooting. We were having the same stmptoms and had a hunch we both got bad dampeners. I put my truck on the dyno for a better evaluation and sure enough like his, the noise was coming from the front. Pulled the Vibratech damper off, put the OEM one on and the problem instantly went away.

Returned the dampener to the supplier and they have sent it back to PukeDits for warranty. They won't warranty it without testing it so it'll probably take a while, we'll see if they try to deny it. They swear up and down that they have never had one come back before, what are the odds that two of us here got the only two bad ones in existence?

[Rawze]

(02-27-2017 )Camstyn Wrote:  ..
They swear up and down that they have never had one come back before,
...

BIG RED FLAG IF YOU ASK ME. ESP. now you say you got em from that big-name rip-off puke dlete company!!!

[Hammerhead]

(02-27-2017 )Rawze Wrote:  BIG RED FLAG IF YOU ASK ME. ESP. now you say you got em from that big-name rip-off puke dlete company!!!

Well that's kind of a roundabout of where they came from. Both Camstyn and I bought Vibratech dampers from Artic Truck Parts. ATP is a puke-dits dealer, so that is where they source the dampers from. They can't buy the Vibratech direct as Dave's Diesel Repair in Edmonton has the exclusive Vibratech (and the other stuff under the same umbrella) company dealership...and of course ATP won't buy from DDR, so they go to their vomit source and get them that way.

***my understanding is: The vomit company is just a reseller and has nothing to do with Vibratech's manufacturing, they are just a large customer of Vibratech. Wouldn't be the first or last time I was wrong though.

When I put my truck on DDR's dyno to diagnose and we found the problem, Dave wanted to know how the hell ATP was getting these dampers because of his exclusivity. He told me that he's only had one or two fail during the one year warranty, but he's had about 5 or 6 fail in total over his years as their dealer. He told me that their failure rate is basically the same as OEM Cat, so he thinks there a pretty good product.
If it fails again, the hell with the warranty, I'll buy OEM Cummins. Which will be too bad, because Vibratech's markings for A, B, C, IP, & TDC are so much easier to find than the OEM one. Cummins stamps theirs too lightly IMHO, where Vibratech machines the lines and letters in. Stevie Wonder could read it!