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Valve train noise with first DIY tune installed.

THEFERMANATOR

FRANKENBURBAN
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I was reading those articles in the cetane thread.
That one page was on glow plugs.
The writer said at 30*F that the GP cycle was about 8 seconds.
I have never timed mine but, it always seems like it is about ten or thirty minutes. But of course, that is My impatience timer ticking along. It actually does seem like more than 8 seconds.
There is also instructions for a GP bypass option using a three way switch, temperature sensor and a relay.
That seemed interesting. After I have had the engine of My truck running, shut it off to go into a store or, etc, when I get back to the truck, twist the key, I always wait for the WTS lamp to extinguish before going to start mode.
On several occasions, I have twisted to start position before the WTS goes out. It has always extended the crank time by a little, not much but enough that I think I am better off burning GPz than I am the starter. 🤷‍♂️😹😹👍
60G glow plugs run about 10-12 Seconds of glow time for an average cold start iirc. I know a 60g glow plug is just starting to get good and hot in about the same amount of time as it takes for a 9g glow plug to explode. So glow times changed considerably in newer trucks with the 60g glow plugs from the factory.
 

dbrannon79

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@THEFERMANATOR this would explain why I have had glow plug issues starting up in the mornings. I didn't think about it but if the 60G's are a little slower to heat up explains why 5 seconds the stock tune gives isn't quite enough and 8 seconds eliminates the stumble and load of smoke!
 

dbrannon79

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Well guys I haven't had a chance to dig into the noise the truck is making, but it seems it is getting worse in the last few days. just took a 15 mile trip out of town and back, noticing the rattle is now constant where it can be heard accelerating, coasting down hill and all. it almost sounds like a light rod tap or a piston slap! my plan this weekend is to return the IP timing back to stock spec so it will quiet down the engine a little, reinstall the stock tune chip and then start checking the injectors.

when at idle it seems random where it will have a single knock and then goes away for a second or two, then returns. when coasting down hill it seems louder than accelerating, but it stays constant and you can time it to a rhythm with the rpm of the engine. it's not super loud like a bad rod knock so I am still hopeful that it's just an injector.

using GMTD and disabling one injector at a time, the noise completely stops on the #2 cylinder, but listening to it almost sounds like it's around the #8 cylinder. disabling the injector only means that the detonation force is no longer forcing that piston down so it can still be a piston or bearing. I'm praying 🙏 for just the injector. I think I can get #2 and maybe #8 out without pulling the turbo, so this will be an adventure moving those two to the drivers side to see what happens.
 

DieselAmateur

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Sounds like you've already narrowed down the issue, but if not 100% on it being an injector/ rod/ valvetrain remove the serpentine belt and run the engine for ~20 seconds to see if it's anything in the accessory drive system. I had an awful noise that increased with RPM that I first thought was bad a/c compressor, only to find out after purchasing a new compressor that it was the vacuum pump gone bad.
 

dbrannon79

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#2 is right next to the vacuum pump! I hadn't thought about that.

just out of curiosity, can a injector pop tester replicate the noisy injector if its an injector that is knocking?

I have been looking at the AC Delco pro injectors on RA. thinking that if it turns out to be one. I may order those as replacements. the ones I have in the truck now came from the local auto parts. I can get warranty on them, but like everything else I have had to do jobs twice on almost everything I bought from there!
 

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I also forgot to mention that the engine light came back on again. Was on the freeway headed up hill at about 75. As soon as I started down the the incline and slightly let off the pedal the light came on. On the tune I had disabled code 78 since I tuned it to max boost out at 14 psi. Boost was up close to 10 when this happened. I’ll read the codes tomorrow afternoon but I’m betting that it’s the same code 36 I got before on the injection pump
 

dbrannon79

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Questions questions…. I was reading up on another form on diagnosing code 36. I am finding that code 35 is closely related. Also they are talking about the ESO engine shutoff solenoid and the voltage it sees possibly causing pulse width issues. This brings me to a question…

when I started this thread I had the laptop connected and was playing with the injector cutout when I found that I can turn off #2 and the knock vanished. While I was jacking around I did cycle the fuel shutoff solenoid with the engine idling. It did studded and stumble but did not shut down the engine. Could I have caused a problem by doing that or should the engine have shut off instead of just stumbling?
 

dbrannon79

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Part one on my plan successful, i think. lol after my trip home from work, while the engine was still hot, I checked the codes and re timed the IP back to factory spec. I had code 78 for the wastegate solenoid. thought I had disabled that code, not apparently not. I tested it with the laptop and it's bad. not responding to the pcm commands.

I also got the IP timing set to -0.53 by tweaking the IP just a hair towards to drivers side. no difference in the engine noise level.
re checked the knock sound by toggling each injector off and back on. still it only disappears when I turn off #2.

part two of my plan tomorrow when the engine is cold... swap #2 and #1 injector and see if the noise follows.

to be continued......
 

dbrannon79

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one other thing I did, and now just thinking... when I tested the wastegate solenoid with the laptop it did not respond. it just dawned on me that when I installed this tune, I used my OE 95 PCM. now that I am remembering, I had ran that 94 junkyard PCM for a bit and realized when I had issues with the wastegate solenoid before, it seemed to work on that PCM.

while I was testing it, I unplugged the connector. when I did, it released and the wastegate opened, connected it back and it sucked the actuator back up again. tomorrow I will check the other PCM and see, but for the tune I am using. it's based off the 1995 stock one. can the 94 PCM accept a prom from a 95? just curious on this because if my PCM is gone funky Ill be trying to use the junkyard one.
 

dbrannon79

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Part two done. swapped out #2 and #1 injector. yet now disabling any of the injectors only makes the engine run with a miss, no change in the noise. the knock is not as pronounced as it was. I think I am going to leave it alone for a while. It's too hard to desifer a diesel rattle from a lifter/knock/ rod at this point.

what is strange though, I think I just discovered that the original PCM in my truck has some funky issue. after warming up the engine I retested the wastegate solenoid by toggling it on and off in GMTD with the laptop. it did not respond. pulled out the 94 PCM I had gotten from the junkyard, pulled the prom and installed the tuned prom that was in my PCM, connected everything up. checked the TDC offset. had to do a re-learn to get it set. Then I cycled the wastegate solenoid again this time with the 94 PCM from the JY. it worked. no issues. I guess I have a failing PCM.
 

dbrannon79

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Is there anything I need to worry about running this 94 pcm vs my original 95 pcm? Here’s a photo of the numbers on each. The 95 has the BPAA prom code which I just plugged into the 94 pcm and hooked it up. 32D620CD-9E99-415A-AE8C-E138305A8232.jpeg375D327D-3AA7-4420-8333-BF49D42847A1.jpeg
 

dbrannon79

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Hey guys, Happy Thanksgiving everyone.

I wanted to post an update. over the past week since returning the TDCO back to within spec (-0.67) and changing the oil. I was 500 miles shy of my normal 3000K change. I added a quart of lucas oil stabilizer to the mobil delvac 15-40 I usually run. the only change I have noticed is with the lucas additive the oil pressure seems to stay more constant at 40 rather than dropping to 25 at a stop light or idle when warmed up.

the noise has not changed one bit. I talked to a friend at the shop I work at who drives a burb with a 6.5. he seems to think it has a collapsed lifter or a wrist pin. I did ask him if it was possible to change lifters without pulling the head since there is no access in the engine valley. he wasn't sure. would any of you all know that answer? I would be willing to attempt replacing the lifters on the passenger side if they can be done without pulling the head. would ether a collasped lifter or a bad wrist pin get worse quickly or remain the same until fixed? since I have been driving it week after week like this mostly short trips to and from work (6 miles one way)

I wish a couple of you guys were near by where I could have yall listen to it in person. it idles and drives fine, no hesitation or miss, no smoke except for the little bit on a cold startup. even the factory tune vs my DIY tune doesn't change anything other than the extra fuel and power with the DIY tune. (only added more fuel and boost.)

to better explain the noise I hear, on a cold start up the engine sounds normal with all cylinders clattering, then after the engine warms up most of the clatter quiets down except for what seems to be one cylinder on the turbo side of the engine. I would do a video with my phone from cold startup to fully warm but I know my phone wont do justice for listening to sounds like that.

driving this like it is hoping we actually get a refund durring tax season, I will be looking for a cheap running engine to get and fix up as a replacement in the coming months.
 

MrMarty51

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By dropping out one cylinder at a time, the bringing it back to life, if one cylinder gets louder or the noise changes but dont go away, most likely a piston or wristpin. If the noise goes away, a rod. If the noise does nothing, then most likely a valve train noise.
 

dbrannon79

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the noise does go away when I turn off #2 injector but it also misses and shakes badly until I turn it back on at idle. doing this at a higher rpm the noise only gets quieter turning off and on all injectors one at a time. I have swapped the #2 and #1 injector with no effect. but while standing over the passenger side of the engine, the sound doesn't seem to be in the front area, it seems to be towards the rear of the engine. I had my doubts on the injectors ever since I had put them in. if I could get my hands on at least 4 used ones that are still good, I would try swapping them out just to see if something changes. I had thoughts of asking Big T if he still has the old marine injectors he just pulled from his rig to try. maybe I could get them pop tested and try. just not wanting to put much $$ into this engine if it's a gonner

I have watched youtube videos on rebuilding them, they seem fairly simple to do.
 

Will L.

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The lifters can be done without removing heads. Remove:
Negative battery cables
lntake
Ip lines
Valve covers
Rocker arm shafts
Push rods - make sure to note which end is up
Lifter retainers
Lifters.
Go back in opposite order
Consider new rocker buttons when it goes back together.


There is a few things that can create that knock.

locate -is it worse under oil pan, lower block middle of block, valve cover.
Get actual stethoscope is best to find it.

If you identified which cylinder and swapped the injectors and it did not follow the injector- then don’t bother with new or used injectors- you already eliminated that.

having normal power but a knock means not ip or ip line most likely also.
Piston damged is possible- my chewed up piston from the glow plug breaking off had me thinking bad injector. But I had never seen that before so gonna say crazy rare.
rocker arm/ or
arm retainer pin.
Bent rod
Bad wrist pin
Bad main or rod bearing
Bad main web
Crankshaft

with 300,000 it is a crapshoot if not fixing it means death in short time or if opening it up would lead to one new part strains the next into breaking.

Oh yeah- can you remove cdr and hear it better through hole?
 

93detroit

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Mine Optimizer has always sounded pretty much like that. Oil pressure is good, oil usage is less than a quart to 5k miles (amazing with a cdr and a heavy foot). I believe it's a lifter- the longer I drive it and the warmer it gets, the noise goes away.
Engine has no more than 60k miles, as the military pulls them at 40k Max.
 

dbrannon79

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ok guys, I hope someone can tell me there is still hope here.... I haven't wanted to check fearing what I might find. this knocking has been driving me nuts, it hasn't seemed to get any worse unless my ears are deceiving me but has not gotten any better ether. I have been driving it every day back n fourth to work plus short trips into town.

today I decided to try looking and listening again, also pulled my OPS and connected a test gauge to verify my gauge is reading ok. connected a test gauge and I see 40 psi at idle until it warms up, then drops to 24 psi. using the high idle switch (1k rpm) the pressure is right back to 40. so that seems good, not perfect, but good.

I grabbed the longest screwdriver I have in my collection which turns out to be a 22" 1/4" nut driver. have no idea where I got it from. started probing the injectors I could get to and various places on the block.

as it turns out the most pronounced area I can hear and actually feel the thump in the handle is right at the farthest back upper bolt on the passenger side valve cover. I can also hear the knocking through the #8 injector too but I think it's worse on the valve cover bolt.

I did slide underneath and probe where I could and still get my ear on the handle. starter mount bolts, trans pan, exhaust manifold area near #5 and #7 glow plugs, lower area of the block where the turbo oil drain and behind the starter bracket. I can't get to the #5 or 7 injectors without tearing into things, but #2 and #1 sound smooth as I had swapped them before.

the noise sort of sounds like a small ball pien hammer tapping on the block in the area behind the turbo, but a friend of mine when he heard it said it sounded more like a "diesel" knock.

do y'all think there is any hope or is it best to cut my losses and drive it till she blows?
 

NVW

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I've just read this thread, I believe HD trucks used a different IP between 94 and 95. Some tried to use the 94 IP as it was a higher output IP. They don't mix.

Another thing I would try, it won't hurt anything, put an ounce of gas line antifreeze in the oil. It will unstick a lifter. I've done it before, something I learned 40 years ago from an old mechanic.
 
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