P0341, P0477 and a loud banging

[JNutter]

I tried to start my truck just now and it cranked really slow, took a while and when it did fire it made a loud banging. I shut it down right away and started it again, it did the same thing. Waited 5 minutes, read codes, gave it one more quick try. Same thing.



It's +13 degrees F here, and the dealer used the 10W30 when they changed the oil at about 3000 miles, so I doubt that it is any type of a problem with cavitation in the oil pickup that others have seen in extreme cold. The truck has 4896 miles on it right now. I have started it at -10F with no problems, not plugged in. The truck wasn't plugged in today either.



I had a bad power steering hose leak a week ago, and a dealer fixed it under warranty. I kind of doubt it is related, but you never know, so I thought I'd mention it.



Anways, code 341 is camshaft position sensor performance/rationality and 477 is exhaust pressure relay low.



The truck is completley stock, with the exception of the dealer installed Jacobs exhaust brake. No chips. Not even gauges.



Does anybody have any ideas as to what is going on, or should I wait to hear from the dealer? They don't open until tomorrow morning, and they'll have to tow it because I'm not driving it when it's making that noise.

 

[fraserrj]

Did you check your exhaust brake if it was shut for some reeason it would be hard to turn over I don' know about the backfire.

 

[JNutter]

I'm not sure how I'd check to see if the exhaust brake was shut. The mechanism is buried under the vaccum diphram. Is there an easy way to tell? Could that have anything to do with the codes and the noise?



The noise wasn't a back fire. It didn't sound like any type of bottom end or valve train noise. It almost sounds like something with stripped gears or splines, but it's not as sharp as broken metal parts clashing. Maybe like stripped plastic gears...

 

[TCDiesel]

STARTS

How long did you leave it run after you started it.

 

[JNutter]

I shut it down right away, but I did start it again a few minutes later to see if it still made the noise. It started quickly, but made the noise. It's a bad noise. I'm not going to start it anymore.

 

[Vaughn MacKenzie]

Wow, I have no idea, I would have it towed to the dealer to be checked out. I agree, don't start it again. Sounds like something is binding up which is causing the drag on the starter. Maybe the high pressure injection pump is seized up and making the racket??



Vaughn

 

[JNutter]

You might be right about that binding. The HP pump sounds right. I can't think of what else could bang like that without locking up the engine. The two codes don't really go with that though.



I'm going to call in the morning and request the tow truck. It'll probably be a day or two before I get an answer from the dealer.

 

[DCTECH]

Is your crankshaft position sensor hitting crankshaft pulley? It is mounted below p/s pump. Also there is TSB 18-03-04 that applies to trucks built before 12-10-03 for erronous code PO341(camshaft position signal) , needs reflash on Cummins ECM to fix.

 

[JNutter]

The tow truck will be here shortly, but I had to get that one last thing to check in before he shows up



The CPS bracket is part of the aluminum front cover casting on my truck. The protrusion that the CPS sits in is about 3/4" thick and there's about 3/16" between the end of the CPS and the crank. If anything, it seems like the CPS is too far away. I know the CPS on a Jeep 4. 0 is mounted about . 020" off the crank. You use a thick paper dot to space the CPS out on a Jeep, and I could put a stack of those dots between the CPS and harmonic balancer on my truck. It seems funny that this one is so much further out, but Cummins knows what they are doing.



I should get a call from the dealer with a diagnosis some time tommorrow.



I appreciate you guys throwing out things to check. It pains me to let anyone else work on my stuff. I really wish I could figure it out myself, but I think this one is over my head.

 

[TCDiesel]

STARTS

What dealer came and pick it up.

 

[JNutter]

I bought it at Elk River Ford/Dodge/Jeep, so I called them. They had Collins Bros towing come down and get it.



Hopefully the dealer will be able to tell me what's wrong tomorrow.

 

[JNutter]

They took a quick look at it today. I guess the diagnosis only extended to starting the truck, hearing the noise and shutting it off. In the words of the service writer 'We think something let go in there... ' followed by a little bit of speculation on what it might be.



I'll skip the speculation for now.



They are going to push it into the shop tomorrow and start tearing it down. I'll post when I learn something.

 

[JNutter]

update 2-18-04

They looked at the truck today and found that the problem was with one of the rocker arm bridges. The service writer didn't seem to have too many details. The receipt that they gave me looked like they just had to tighten down the old bridge, but he told me that they had gotten a new bridge to replace one that had broken. I don't know if I'll ever find out exactly what they did.



Anyways, they put it back together, set the lash and and it was running perfectly and sounded great. I drove it home and noticed a valve train tick about 8 miles into the 10 mile trip. I popped the hood to confirm what I heard and called to say the truck was coming back. The tick was louder by the time I got it back there. I have to wonder if the cam or lifter was damaged when everything was banging around. One good nick on either could cause accelerated wear.



Another funny thing, they said they didn't find any codes, but I know that 341 and 477 were in the computer when the tow truck driver picked it up. I think they forgot to check before they disconnected the battery but didn't want to admit it.



And another funny thing... I wanted them to check on why the ex-brake wasn't coming on when it was really cold out and they told me it shouldn't. After some discussion I realized they didn't even know what it was or that it was a Mopar accessory or that they had installed it. I ended up faxing some of the documentation regarding the ex-brake to them, and then they believed me after reading it. They still couldn't find any problem with it. At least it's entered in the truck's history in case it ever comes back. I doubt that I'll see the problem happen again before next December or January now.



Time will tell as to how the valve train problem plays out.

 

[Prairie Dog]

Hmm, lets see... they have never seen an exhaust brake nor do they know what one is? So it's pretty clear a diesel certified tech didn't work on your truck.

 

[JNutter]

I don't know if anyone else is interested in these updates, but here's what happend today.



I got a call about mid day saying that they found the lash on cylinders 3 and 4 to be 'way out of spec' and that they had adjusted it. They also said they had figured the problem with the ex-brake. It was just the switch on the shifter.



I picked up the truck around 6:30 and it was working great. They said to come back next week when the replacement exhaust brake switch comes in.



I got a chance to ask a couple questions while I waited for their driver to bring the truck around. The service writer confirmed that no parts had actually broken through any of this. They had only put the rocker arm assembly back together on the first visit and they had only adjusted the rockers on the second visit. I asked if the mechanic was confident that nothing else was damaged and the service writer said it was all OK and that the mechanic was very experienced and had gone to Cummins school. He also said that extended idling can cause the valve train to come loose. I have a hard time buying that, but I let it go for now.



The truck seems to be fine now, but I didn't do any long test drives. I got about 25 miles on it. I'll try to drive it to work next week, if the weather is decent.



I've got 95,000 miles left on the engine warranty. I hope I don't need it again, but time will tell.

 

[gonzo2]

Judging by the number of views, lots of us are interested in your updates. Glad your rig is running well again.

 

[Vaughn MacKenzie]

Thanks for the update JNutter, wow that's a strange story/experience. You certainly did the right thing by not starting it anymore and getting it towed in!!! I am glad to hear they got you fixed up and you didn't have any significant trouble getting it fixed right (even though it took two trips).



It's good you have 95K left on your warranty incase anything happens with the rocker arm again or push rod(s). Hopefully there's not a defect with the threads that let it wobble slightly and work itself loose again.



Vaughn

 

[Rescue Ram]

JNutter wrote:

He also said that extended idling can cause the valve train to come loose.

Maybe he was refering to the bent push rods that can occur in ISB engines due to low EGT/ cylinder wash? If the valve train were to come loose at idle, imagine running the engine at high RPM's...



Please keep us posted



Brian Z. Oo.

 

[JNutter]

Thanks for the support guys.



I put almost 100 miles on it today. So far it seems OK. I don't hear anything that I wouldn't expect from an engine with mechanical lifters.



It's got me paranoid. I feel like a 6. 0 Powerstroke owner, waiting for the next problem. I've got the 800 number for roadside assitance in the cab now, and I'm going to get a cell phone.



I plan to drive it as much as possible between now and our family trip to Moab in May. Hopefully some miles will expose any remaining residual problems.



I'll post again if any more problems come up.

 

[rbattelle]

Good thread, JNutter! Once again, someone gets the moron treatment from a dealership... big surprise. (duhh... what's an exhaust brake? #ad
)



Have you considered taking it to a nearby Cummins service center and having them check the valvetrain? It would cost you, but might provide some peace of mind.