Big Truck Mechanics

[DCGallim]

Not sure if anyone here can help. I know Mike79 and Beef15 work on heavy stuff but don't know about anyone else.

Got a 05 Granite with the ASET engine (hey there's your problem). It's had a problem with cutting off and not restarting for the last year or so, very intermittent. It can cut off one day and not restart for a month then you hand prime the system and it fires right off and will run fine for 6 months. There's no rhyme or reason it does it, just when it feels like it I guess. To date I have changed the injectors, fuel pump, filters, check valve, bypassed the tank and filters to see if that's the problem, I've put a test light on the EUPs and they all blink as if they are firing off, I've sent the computer off to have it checked. So far everything I've done has fixed nothing. It will run on ether, it will turn over and act like it wants to start but never does. I've also noticed when this problem occurs it will blow oil past the seals on the oil filters. So experts I come to you, what is going on here? What do I need to do to figure out what's going on here? And finally how to I get this truck back on the road other than setting it on fire?

 

[Qball]

You mentioned oil blowing past the seals on the filters. That sounds like the crankcase is pressurizing for whatever reason. Have you looked at the turbocharger? I realize the turbocharger wouldn't prevent the engine from starting but it sounds like something is causing the crankcase to pressurize and depending on the design, the turbocharger can cause that.

 

[Mike79]

Oil sample results? Check blow by......you said you bypassed the fuel tank......guessing during one of her fits you used a remote tank for fuel? Look at your fuel lines I have seen plenty have a leak that would suck air if turned just right.

 

[DCGallim]

You mentioned oil blowing past the seals on the filters. That sounds like the crankcase is pressurizing for whatever reason. Have you looked at the turbocharger? I realize the turbocharger wouldn't prevent the engine from starting but it sounds like something is causing the crankcase to pressurize and depending on the design, the turbocharger can cause that.

I've put a new turbo on it not long ago. It had the problems before and since then.

 

[DCGallim]

Oil sample results? Check blow by......you said you bypassed the fuel tank......guessing during one of her fits you used a remote tank for fuel? Look at your fuel lines I have seen plenty have a leak that would suck air if turned just right.

Haven't tested the oil, compression test came back good and yes I sat up a remote tank and it still wouldn't run. It's getting fuel to the injectors. It's almost like the injectors aren't firing at the right time. Tomorrow I'm gonna volt test the starter to make sure it's not pulling so much it's making the computer act stupid. From there the only thing I can think of is bad o rings on the electronic pumps.

 

[Mike79]

Some engines have an rpm they must turn when turning over or the inj. will not fire......also take a look at the inj harness.....International had plenty of inj harness issues with the valve cover gasket harness.....might need someone who can monitor the ecm when it is acting up......

 

[DCGallim]

Some engines have an rpm they must turn when turning over or the inj. will not fire......also take a look at the inj harness.....International had plenty of inj harness issues with the valve cover gasket harness.....might need someone who can monitor the ecm when it is acting up......

The harness also came to mind. I'm just trying to eliminate things I can fix myself before it has to go to Mack. I tried to move the harness around hoping I'd knock a short loose but that did nothing. The only sensor on the fuel system on those ASET engines is a Fuel temp sensor so a sensor isn't the problem.

 

[Qball]

Daniel,

Bruce Essicks Truck Service is a good heavy truck shop in Thomasville if you don't want to take it to Mack.

 

[Jp8819]

Its not a faulty cam or crank sensor is it telling it wrong time to fire injectors?

 

[DCGallim]

Its not a faulty cam or crank sensor is it telling it wrong time to fire injectors?

It could be but it's not throwing any codes.

 

[muskrat]

Probably a missing ground strap..

 

[DCGallim]

Probably a missing ground strap..

Grounds do crazy things to diesels and I actually cleaned off all the grounds when it did this a few months ago just to be sure that wasn't making the computer go full retard.

 

[Mike79]

Its not a faulty cam or crank sensor is it telling it wrong time to fire injectors?

I'm not familiar with the engine but a faulty one/wiring could cause a no start.....lots of 6.0's towed in that I drove into the bay

 

[Mike79]

Also take a look at alt out put....to much is just as bad if not worse than to little.

 

[Mike79]

Another thing to check is ecm voltage.....I have seen plenty of resetable fuses go bad under a load is the best way to test them......

 

[Jp8819]

It could be but it's not throwing any codes.

Is that reading with a code reader or just based on check engine light? I know we have a 04 international that was having a problem and it would not show the light since problem would come and go but it still had a code stored to help narrow it down.

 

[Beef15]

Sucking air was the only thing that came to mind from your description. We've had some drawing air through the separator bowls lately, and one with a pinhole in a filter.

Not familiar with the ASET engines, only Mack line I mess with is the newer MPs, anywhere to check the fuel pressure after the lift pump?

If I didn't work for the shitty I'd rob the laptop and see if Tech Tool says anything useful. Intermittent tends to be electrical IME.

Low voltage can cause a lot of erroneous things, but usually if you can run them on ether for a minute and they don't pick up that's not it.

Blowing oil is an interesting symptom for a no start...

I'll read up some tomorrow and see if I can learn anything.

 

[DCGallim]

Is that reading with a code reader or just based on check engine light? I know we have a 04 international that was having a problem and it would not show the light since problem would come and go but it still had a code stored to help narrow it down.

Neither. No lightning bolt and nothing when I hook it up to the computer.

 

[Beef15]

Neither. No lightning bolt and nothing when I hook it up to the computer.

Well there's your problem, Mack's never run without the lightning bolt

 

[Qball]

Blowing oil is an interesting symptom for a no start..

Yeah. If oil is blowing out past the oil filter o-rings and it correlates with the shut down/no start condition, there's probably more going on than meets the eye.

 

[Scsmith42]

The computer may be shutting off the injectors due to excessive oil pressue, which could be caused by a sticking pressure relief valve in your oiling system. Install a mechanical oil pressure gauge and watch to see if there is a trend in the normal oil pressure versus the pressure exhibited when the problem occurs.

 

[Short Fuse]

I am not familier with that series engine but Scsmith42 is probably on to something. A lot of vehicals use oil pressure to control things like fuel and valve timming. Blowing oil past the seals is a definate red flag. Have you googled your simptoms for your exact make and model? Known issues will most likly be posted somewhere out there. I just got curios and gogled your issues it seems mack does have some servie bulletins pertaing to your issues. I would post them for you but me and this new tablet have not learned to dance yet. So just google 2005 granite aset oil blowing by filter seals and it should pop up for you.