SOLVED: Another misfire chasing threads (2008 express van)

[exp500]

Not exactly what I wanted to see, But usable. Your vacuum is low. How much of that is EGR I don't know (decel). At your most efficient cruise speed, engine vac should be 17-19. That shows rings or valve leakage (again EGR involved in number) . So what it points to from two short partial tests is small Vacuum leak somewhere or leaky EGR or sticky lifter/carboned valve (that 2 inch vac drop miss at idle). Recommend an oil change and a can of berrymans in gas for(#7) with read thru on vac gage diag especially a 60's chart that shows more tests.
Vac diagnosis is valuable in steady state runs usually, as hiccups show. Between your scanner recording live data and a glance at the vac guage occasionally or when you feel a change should generate a solution. Keep posting results and Good luck.

 

[Tonyv__]

Not exactly what I wanted to see, But usable. Your vacuum is low. How much of that is EGR I don't know (decel). At your most efficient cruise speed, engine vac should be 17-19. That shows rings or valve leakage (again EGR involved in number) . So what it points to from two short partial tests is small Vacuum leak somewhere or leaky EGR or sticky lifter/carboned valve (that 2 inch vac drop miss at idle). Recommend an oil change and a can of berrymans in gas for(#7) with read thru on vac gage diag especially a 60's chart that shows more tests.
Vac diagnosis is valuable in steady state runs usually, as hiccups show. Between your scanner recording live data and a glance at the vac guage occasionally or when you feel a change should generate a solution. Keep posting results and Good luck.

Yeah it seems anytime I am accelerating or at high rpm. The vacuum is extremely low. Someone else recommended I try a leak down test on that cylinder and since you’re saying possible valves or rings I’m more motivated to do the leak down test….
Tough for me to get a good video. I need a co pilot or 2 cameras to record RPMs and the vacuum at the same time. Or just narrate better. But I appreciate you looking at the videos and giving me some input

 

[exp500]

You don't need to video vac gage, just glance at it once in a while. Your scanner should record 10-15 minutes or more .
Again, read about vac diagnosis. Maybe even unplug EGR. ( I'd have to review cautions on that)

 

[Tonyv__]

You don't need to video vac gage, just glance at it once in a while. Your scanner should record 10-15 minutes or more .
Again, read about vac diagnosis. Maybe even unplug EGR. ( I'd have to review cautions on that)

I was searching Just out of curiosity and pricing. Apparently my truck doesn’t have an EGR valve. No matter where I look. Rockauto for example. I can find an EGR valve for a 96 express van. But when I put in 08 express 3500 with 6.0. EGR isn’t even an option in the exhaust section. No luck Amazon. No luck elsewhere. Is it called something else?

 

[OR VietVet]

No. GM did away with egr valves on some engines at one time and continued that way, as far as I know, but changes come and go.

I have no idea why what I found out at RA is what it is but:

2008=no egr valve or gasket
2007=egr gasket listed but no valve
2006=egr gasket listed but no valve
2005=egr gasket but no valve
2004=egr gasket but no valve
2003=egr valve and gasket listed

This is for the 3500 Express Van with 6.0 engine

 

[Tonyrodz]

No. GM did away with egr valves on some engines at one time and continued that way, as far as I know, but changes come and go.

I have no idea why what I found out at RA is what it is but:

2008=no egr valve or gasket
2007=egr gasket listed but no valve
2006=egr gasket listed but no valve
2005=egr gasket but no valve
2004=egr gasket but no valve
2003=egr valve and gasket listed

This is for the 3500 Express Van with 6.0 engine

I just checked RA for an egr for my Express 2500 with the 4.8. No dice, nothing shows, but like you said, they only show a gasket. Doesn't make sense to me. If there is a gasket there--where would it be, and could that be a source of a vacuum leak? I'm curious because I'm still having an issue too.

 

[OR VietVet]

Maybe the gasket is for a block off plate where the egr valve used to be.

Kind of like an oil cooler block off plate.

 

[Tonyrodz]

Maybe the gasket is for a block off plate where the egr valve used to be.

Kind of like an oil cooler block off plate.

Would the egr be on the intake?

 

[OR VietVet]

I read someplace where they were also mounted at back of throttle body but did not pay attention to application when I was looking. I woud just look high and low for where the gasket may fit.

Sorry, gotta go @Tonyrodz, time to drop a deuce. Will be back with clean hands

 

[Tonyrodz]

I read someplace where they were also mounted at back of throttle body but did not pay attention to application when I was looking. I woud just look high and low for where the gasket may fit.

Sorry, gotta go @Tonyrodz, time to drop a deuce. Will be back with clean hands

Take it light Ron