LLY: Truck Quit, Unusual Symptoms

[BUCKHNTR]

Hey Guys,

My brother ROBSDMAX posted up for me previously to help me try and diagnose the problem, and I am still very confused and the truck has now finally quit on me. I'm totally stumped and I'm hoping someone can help me diagnose my issue.

Truck Background. 2005 LLY Duramax, 330,000KMS, HSP Intercooler Pipes, Stock Turbo, Stock Injectors, Head Studs, EFI by PPEI. If you need any other information please just ask.

February 2015 I did my head gaskets, engine out of truck, head studs and grade C gaskets, the usual repairs for a head gasket repair, as well as the Modded Water Pump and Loctite on my Oil Pump Nut. Balance Rates good, truck running awesome.

First problem was blowing an Injector Return Line off Cylinder #6. Reinstalled the line and the clip and never blew it off again. Checked my Balance rates, all good.

Drove another 2-3 months, then truck started developing an annoying vibration at idle in both Park and in Gear. Truck would shake enough to rattle my keys together and move water back and forth in my water bottle. Checked Balance rates, Cylinder 6 was +12, Cylinder 7 and 8 both -7.

Decided to replace the Injector in Cylinder 6 as I thought that was the cure. Ordered OEM Reman from GM dealer, and installed myself. Balance rates stayed the same and made no difference in Balance Rates. On the way home from my shop replacing the Injector, the return line blew off Injector #8. Reinstalled and has been fine since then.

Took my truck to my local GM Dealership, Service Manager is a good friend and looked after me as best he could. Did as many tests as he could and didn't find anything wrong beyond the obviously poor balance rates. Checked compression. Cylinders were +/- 80PSI, but were all above 350PSI. Seemed out of specification somewhat, but wasn't too worried. Left GM Dealer, hooked trailer up to tow my sled pulling truck up north.

Truck started idling funny at the lights with the trailer on. Slight Surge, and almost dying off. Pull in the driveway at the truck pull, truck shuts off dead. Checked the Primer Cap, lots of pressure in the Primer, lots of Rail Pressure on Edge. Sit for 30 Seconds, try starting the truck, started and ran another 45 seconds to get me into the fair and then quit again.

Balance Rates still the same, 4 Very Good, 3 @ +/- 5 or 6, and 1 @ + 10-12

Checked the codes on my CTS. 8 Glow Plug Codes and 1 U0105, which I have called and confirmed with my dealership was caused during the Compression Test they did and they forgot to clear the codes. Checked all wiring and all fuses, and Ice Picked all the Injector Connectors. No start.

Truck is now at home and refuses to start. Need to check my codes with my brother's V2 to see if there is any codes that the CTS isn't reading. My question for you guys is, what do you think is wrong and more importantly, will P0336 be read by the CTS?

I have read loads of threads, and have read the thread titled P0336 by Schwinn68, and am almost certain by the likeness of our symptoms that my Reluctor Wheel has come off. Seems deadly close to the symptoms I had. But don't want to tear my front cover off until I hear your opinions.

Thanks in advance guys

 

[JoshH]

Which cylinders are showing good balance rates, and which ones are showing bad? You can check if your reluctor wheel is loose by removing the crank position sensor and going through that hole to test it with a small screwdriver or a pick.

 

[BUCKHNTR]

Thanks for the reply. Injector 7 shows around 5-6, Injectors 8 and 3 Read -6.5 to around -7.0. Injector 6 which was replaced reads around 9-12. All remaining injectors are +/- 0.5 to 1.5

Will have to bring the truck down to the shop to remove the Crank Position Sensor and see how the reluctor wheel feels. Do you guys know if the Edge should read the P0336 or if only a Tech 2 or V2 will read these codes.

Also should add that I conducted the Injector Cleaning Process on the Injectors that is outlined on Duramax Forum, and the Balance Rates stayed essentially exactly the same.

 

[JoshH]

Do you know the compression test results for each cylinder? 80 psi is a big swing from high to low.

 

[BUCKHNTR]

Dealer did supply me with Compression Results. Just wanted to also say that my friend who does all my engine work and helps me out huge is a certified Detroit Diesel tech and is extremely knowledgable. He said not to be worried because the Dials on the Diesel Compression Testers often won't hold the results so the technicians just guess. Not sure what you guys think about that. Results were:

1- 340 PSI
2- 420 PSI
3- 340 PSI
4- 390 PSI
5- 350 PSI
6- 420 PSI
7- 360 PSI
8- 390 PSI

Those were the numbers supplied to me by the GM Dealership near me.

 

[Frankin_truck]

Do you have access to s scanner? What do you get for a rpm signal? I know with the my snap on scanner I can Graph the signal you might be able to see a break in the pattern or none at all (would explain your no start)

 

[BUCKHNTR]

All I have access to is a V2 but I believe that should let me scan for the problems. If I were to crank the truck over, I'm basically just watching for the RPM to show up, and if it doesn't then the Crank Sensor isn't reading correctly then? Hopefully that should be an obvious sign of the issue. I guess I could start logging with the V2 and crank it over and watch for RPM signal in the log.

 

[RobsDmax]

Do you have access to s scanner? What do you get for a rpm signal? I know with the my snap on scanner I can Graph the signal you might be able to see a break in the pattern or none at all (would explain your no start)

He has access to my V2 lol.

Thanks Dusty might be calling you....

 

[Frankin_truck]

No problem, you know how to get s hold of me lol:hug:

 

[Burn Down]

Balance rates can be great and you still can have bad injectors. You need to perform a return rate test as well. If your blowing the return lines off, your injectors have some serious issues... Also do as Josh mentioned earlier, pop the crank sensor out and see if the reluctor will spin with a screwdriver.

My compression tester is a Kent Moore Dealer model... My gauge holds just fine Your Compression numbers are not the cause of the no start or the funky balance rates.

What is the rail pressure cranking?

 

[BUCKHNTR]

Update for the thread. Read codes last night, no new DTCs tripped except my usual P1404 EGR Code. Started to worry the Reluctor Wheel wasn't the issue. Regardless, pulled the inner fender and CKP sensor and can wiggle the Reluctor Wheel back and forth around 3/4" to an inch. :woott: Never in my life have I been happy to find a problem, but have been hunting down this issue for a few months!

This week, I am gonna pull front clip and radiator with my buddy and install a new Crank Seal and fix the loose Reluctor Wheel. What is everyone's thoughts on read LocTite on the threads of the Reluctor Bolts? And should I remove, LocTite and reinstall the Cam Reluctor Bolts while I have the cover off as well?

And Burn Down, I am unsure what model Compression Tester they used. I am also still unsure of the Return Line mystery. Can the old Return Line C-Clips wear out and need replaced? I neglected to change those little clips when I did my Head Gaskets and am wondering if I should be swapping all of them?

Also, since the Reluctor Wheel is hopefully the reason behind my very poor Balance Rates, could bad Balance Rates be causing the Injectors to return excess fuel?

 

[BUCKHNTR]

Also, does anyone have handy the Part # for the Crankshaft Reluctor Bolts? I have been looking for the Part # but it would appear every Parts Breakdown I find does not list the number for those bolts.:hug:

 

[JoshH]

I'm pretty sure there isn't a part number for those bolts. Unless something has changed, GM considers the gear and reluctor wheel as an assembly. The reluctor wheel is not a serviceable part separate from the gear.

 

[BUCKHNTR]

I'm pretty sure there isn't a part number for those bolts. Unless something has changed, GM considers the gear and reluctor wheel as an assembly. The reluctor wheel is not a serviceable part separate from the gear.

Thanks for the reply Josh. So, assuming there is still one bolt in the assembly holding them together which I believe there is, I simply need to remove that bolt and find (2) more of those bolts that will match.

What's everyone's thoughts for Grade of Bolt to purchase and the LocTite on the threads? Starting into this tonight so trying to gather some information before getting in there.

Thanks Guys :thumb:

 

[Harbin_22]

I don't think the bolts in them are anything special. Little chrome bolts with 5mm Allen heads iirc. If your relutcor is messed up, I have a spare LB7/LLY wheel and gear laying here. Not sure on LB7/LLY, but LBZ/LMM had guide hikes that went through the gear and reluctor wheel to align it properly. I used two punches that fit tight in the holes to make sure it was straight. I used blue loctite on mine and haven't had trouble with them.

 

[BUCKHNTR]

I don't think the bolts in them are anything special. Little chrome bolts with 5mm Allen heads iirc. If your relutcor is messed up, I have a spare LB7/LLY wheel and gear laying here. Not sure on LB7/LLY, but LBZ/LMM had guide hikes that went through the gear and reluctor wheel to align it properly. I used two punches that fit tight in the holes to make sure it was straight. I used blue loctite on mine and haven't had trouble with them.

Thanks for the reply. Once I get er' ripped open, we will pull one of the bolts and find one that matches up good. I don't think the reluctor is damaged, but if it is I thankfully managed to buy a complete LLY earlier and have been stealing parts from it throughout the year.

Thanks for the reply. DuramaxDiesels was recommended by my brother and seems to have a lot more guys who actually wrench there trucks then keyboard-kowboys who want "600HP and to Roll Coal" lol

Thanks for all the help guys:thumb::hug:

 

[Burn Down]

Update for the thread. Read codes last night, no new DTCs tripped except my usual P1404 EGR Code. Started to worry the Reluctor Wheel wasn't the issue. Regardless, pulled the inner fender and CKP sensor and can wiggle the Reluctor Wheel back and forth around 3/4" to an inch. :woott: Never in my life have I been happy to find a problem, but have been hunting down this issue for a few months!

This week, I am gonna pull front clip and radiator with my buddy and install a new Crank Seal and fix the loose Reluctor Wheel. What is everyone's thoughts on read LocTite on the threads of the Reluctor Bolts? And should I remove, LocTite and reinstall the Cam Reluctor Bolts while I have the cover off as well?

And Burn Down, I am unsure what model Compression Tester they used. I am also still unsure of the Return Line mystery. Can the old Return Line C-Clips wear out and need replaced? I neglected to change those little clips when I did my Head Gaskets and am wondering if I should be swapping all of them?

Also, since the Reluctor Wheel is hopefully the reason behind my very poor Balance Rates, could bad Balance Rates be causing the Injectors to return excess fuel?

If the clip wasn't installed properly then yes the line can pop off. They normally don't wear out though unless someone got a little brody with it and tweaked it.

Reluctor wheel most definitely could cause funky balance rates, as for the high return rates (if it even has high return rates?). No, the reluctor wouldn't cause that, internal issues with the injector cause high return rates.

 

[BUCKHNTR]

If the clip wasn't installed properly then yes the line can pop off. They normally don't wear out though unless someone got a little brody with it and tweaked it.

Reluctor wheel most definitely could cause funky balance rates, as for the high return rates (if it even has high return rates?). No, the reluctor wouldn't cause that, internal issues with the injector cause high return rates.

When the dealership had my truck, they did conduct a Return Rate Test and said they were all normal? I am unsure of how well they conducted the test but they said they are fine. Might have to run my own test of the return rates once I finish the Reluctor Wheel.

Anyone have a good walk-through thread on how to do a return test?

 

[Burn Down]

When the dealership had my truck, they did conduct a Return Rate Test and said they were all normal? I am unsure of how well they conducted the test but they said they are fine. Might have to run my own test of the return rates once I finish the Reluctor Wheel.

Anyone have a good walk-through thread on how to do a return test?

The easiest way to do a quick ck of the health of your fuel system is to crank the rail pressure up at idle. Max it out, if desired and actual aren't within a couple hundred psi of each other then the fuel system isn't working at full capacity. Rail relief, weak cp3, 1 or more injectors with high return rates, external fuel leaks, plugged fuel filters, etc etc.

The test kit looks like thishttp://www.ebay.com/itm/KENT-MOORE-TOOL-J-45873-30-FUEL-INJECTOR-RETURN-HOSES-FLOW-TEST-ADAPTERS-/111737406913?hash=item1a041185c1&item=111737406913&vxp=mtrYou could build your own but you would need the brass adapters that replace the factory fuel return lines.

If the dealer checked them I would say they are probably ok.

 

[BUCKHNTR]

The easiest way to do a quick ck of the health of your fuel system is to crank the rail pressure up at idle. Max it out, if desired and actual aren't within a couple hundred psi of each other then the fuel system isn't working at full capacity. Rail relief, weak cp3, 1 or more injectors with high return rates, external fuel leaks, plugged fuel filters, etc etc.

The test kit looks like thishttp://www.ebay.com/itm/KENT-MOORE-TOOL-J-45873-30-FUEL-INJECTOR-RETURN-HOSES-FLOW-TEST-ADAPTERS-/111737406913?hash=item1a041185c1&item=111737406913&vxp=mtrYou could build your own but you would need the brass adapters that replace the factory fuel return lines.

If the dealer checked them I would say they are probably ok.

Alright Burn Down, I'll definitely get my brother to set up the V2 and check those rates. We had watched Actual FRP and Desired while driving but it would definitely make a difference for Return Flow at idle the most. Again though, my dealer is usually very good so I am hoping there tests were done well.

Will get this repair done and then go from there. Was hoping to sneak the front cover out without removing the T-Stat Crossover Pipe but that just isn't gonna cut it!

More disassembly tonight and reassembly Friday!