Looking for a Gm 6.0l gas expert

[Husky gas axe]

Hey everyone I have a 2003 chev 2500 HD. Been a great truck. It developed an intermittent starting issue. It always starts, but takes a few times. Code shows to replace cam sensor. I did that. Still the same. I also did the complete fuel system new. Starter is new. The truck always starts but it’s aggravating. Thanks for input.
6.0l gas, auto, 100 000 miles
Kyle

 

[1Alpha1]

I own a 2002 1500 HD. Bought it used @ 104K miles back in late 2005. It was spotless, inside and out. I now have 150K miles on it, and no issues at all. Same engine as yours.

Hope that someone will come along and be able to help you. I'm curious as to the problem.

 

[s sidewall]

Did you perform crank/camshaft correlation relearn after installing new cam sensor?

Steve

 

[s sidewall]

When you said codes says to replace cam sensor, that was after running diag chart, and what code is setting?

Steve

 

[s sidewall]

What part of the fuel system did you replace, pump assembly, pressure regular. Let me know so I can check it out at the shop at lunch tomorrow if I don't have a lot on my schedule.

Steve

 

[Husky gas axe]

Fuel pump,regulator and filter got replaced. The dealer did the sensor so I assume the did the correlation.

 

[s sidewall]

Did he diag it as being the sensor or just install and setup?

Steve

 

[Husky gas axe]

It was diagnosed at that. Installed and when he puts the scanner on, code still apears.

 

[s sidewall]

Sounds like he needed to have dug deeper. If you have the code, I'll put the service manual on my pc.
Is it P0341?
Steve

 

[Husky gas axe]

Sorry Steve I don’t remember right now. I am taking the truck to another gm tech in the next town over. I will keep you posted. He thinks possible bad wiring to the sensor? He also asked if the timing chain has ever been changed.

 

[s sidewall]

That's why I asked did he did deeper. Been seeing a lot of wiring damaged from mice at the dealership lately. Keep us posted.

Steve

 

[alleyyooper]

Some of those codes will remain after a fix for 20 to 40 cranks(attempt to start). Should have had the battery disconnect to clear the code after the sensor was replaced.


Al

 

[s sidewall]

GM scan tool should clear everything, both of mine do.
If code resets, it's a hard failure.
Steve

 

[alleyyooper]

Yes the scan tool will clear the code if you tell it to.

Al

 

[s sidewall]

All I use now is my laptop and GM MDI module. Now and then I'll pull out my Tech2.

Steve

 

[Greaser007]

Hey Sidewall,
What do think may be the culprit of why there is intermittent start-up issues ?
Does the 6.0 liter engine have an "Oil Pressure Sensor Switch" to go bad. My old '95 6.5 turbo diesel had these fail often. The oil-pressure-sensor switch shuts off fuel in the event of a roll-over accident. May this be a possible culprit ?

I have a 2007 Chevy 2500 4x4 Suburban with the 6.0 engine. I have only owned it for 1-1/2 years, and put 30k on it in that time. I use it to haul my flatbed trailer and 16-foot Stock trailer. ( it is the 'wife's' car ) What I am concerned about with this engine is that I truly believe I need to find someone who can richen-up the fuel-air ratio.
What I am feeling is a "lean-miss" on a hard long pull up a grade on the expressway. I have taken it to the best shops in my area and both the GMC dealer and GM dealer.
They all keep telling me "all-is-OK" with my engine, but they are not "Feeling-It", and I wish there was a setting on the ECU where when I set my transmission to Tow-Haul mode, that would also richen the mixture to a richer setting to squelch the lean "stumble" which is aggravating.

I drove a -95 GMC 2500 4x4 Suburban with 6.5 Turbo Diesel for 15-years and the electronic injection-pump controller (PMD - pump-driver-module) goes bad and causes stumbling and stalling and all kind of codes to be thrown, which in my opinion is "default" stuff which may not identify the "culprit."
After installing my 3-rd PMD, for 3-years following, my cruise control was intermittent, and I kept getting a check-engine light which I ignored, because I kept getting a Injection Pump code thrown. (there is nothing to rebuilding a pump except new Seals). So I take the rig to the shops, and they want $4k to replace the injection pump. B.S. to that. I finally found that the "Injection-pump" Code being thrown, was because of a Vacuum leak in the waste-gate circuit !
Why couldn't the mechanics have told me this ? ….. I am just the Consumer with the "deep-pocket"
The demise of the vehicle is that the freeze plugs began rusting trough at 280k miles, and the shop wanted $4.4k dollars to pull the engine and replace all the freeze plugs. Just before selling the vehicle, I discovered that I had a leaking vacuum line fitting supplying vacuum to the Turbo waste-gate controller. The fitting looked tight, but leaked. After correcting the vacuum leak, the engine ran like brand new, and in a 500-mile journey, the cruise control never missed a beat, and the check-engine light never came on. Simple little things ……. that an engine analyzer won't tell you. This is why a good Diagnostic Techie is hard to find, when you must go beyond the Codes.

The odometer had 295k on it when I sold it. In the 15-years of ownership I faithfully ran Marvel Mystery oil in with the fuel to assist in lubing the injection-pump, and to also keep the Optical-Sensor clean inside the injection-pump. I never had a valve-cover off of that engine nor did I ever change injectors, or glow-plugs or injection-pump.
The engine oil consumption never changed in those 15-years either, and consumed 1-quart of oil in 400-miles. A Great work truck !

I have to laugh at myself when guys tell me how wonderful their fuel mileage is with their Super-Duty diesels. It is a proven fact that is takes "X" amount of fuel to build "X" amount of Horsepower. You just cannot get 19-miles per gallon driving a 7k lb pickup pulling a 9k lb trailer up into the 6k elevation from sea-level. hahaha

 

[s sidewall]

If the oil sender goes out, only low oil pressure light will come on, will still run. If fuel pump won't deliver the correct fuel pressure, will cause had starts, if fuel pressure regulator stick open some, it will bleed off fuel pressure. On the tow/haul, all I can tell you is to use 3rd gear. To richen up fuel, aftermarket programmer. Some times you do have to think outside the box, especially when GM gives the wrong information in the service manual and you replace a good part that tests show is bad, cause they list the wrong voltage reading. Been there two weeks ago on a Magna Ride suspension system. Tests showed control module was bad. Replaced and programmed it and still same issue. So I ran jumpers from one side of the car to the other. My test showed be a bad shock, replaced it and fixed the problem. Sent GM a reply about the voltage being listed wrong, waiting on their reply.

Steve

 

[Greaser007]

Steve, thanks for the tip on the Oil Pressure Sensor.
I have a thought for Gas Axe: have you rechecked the plug in the crank sensor wire ? I forgot to completely seat the plug one time, and I chased the 'no-spark' problem until I got to item #13 on the troubleshooting list, and the connection had lost continuity.
Does the 6.0 liter have a fuel shut-off solenoid that could be a culprit for Husky gas axe, if the wire circuit had a intermittent break ?

Sometimes I wonder how long troubleshooting before I have a "hard-failure" ! hahahaha ….. good thing they have sedatives like fishing or the wife's cooking.

Where someone mentioned the mice and wiring, I moved into a home that had sat vacant for a few years with 'doors' open. The first night stay, a rat chewed through 2-fuel hoses and 3-coolant hoses in my '02 Subaru ! It totally disabled my car for 3-weeks because the molded coolant hoses were Dealer-only parts which takes time. After the first repair, that booger took out 3-more coolant hoses.
That rodent didn't like having intruders in his space. I have never had any problems since trapping that rat. pesky rodents.

 

[s sidewall]

Forgot to mention, on the newer model, around 2014 and up, with Displacement on Demand, they put a filter under the sender. I've seen those clog up and sender would lose oil pressure causing oil light to come on and pressure to drop to 10 psi or less. Should set a code for intermittent crankshaft position. Rats and mice love wires. I make good money fixing those but can be I nightmare. Especially when you're chasing a dtc. Guy last week chased a code for an hour til he came got me. I looked at the wiring diagrams for his concern. Told him where I would go and check and make sure a connector was good. As soon as he pulled the fuse box cover I saw rat droppings. I told him to pull fuse box and check for wire damage. Didn't chew up but 4 harnesses and two connectors.

Steve

 

[Greaser007]

Yes the scan tool will clear the code if you tell it to.

Al

What component do you think may likely be the culprit of a continuity problem (intermittent at start-up) ?
I watched a YouTube video where the guy did the "pull-test" on the wires going into the plug to the throttle positioning sensor He said he sometimes finds where someone prior had pulled the wire loose from the clip, but the insulation was holding everything in position. He warmed up the wires with blow-dryer and then pulled carefully on each wire individually to see if the wire pulled away from the pin clip and with the insulation stretching on one, it indicated a fractured connection.
Do these efi ignitions have any kind of an "exciter" to go intermittent ? Honda civics had issues with exciters.

Len