Engine Miss

jdg2 · August 19, 2008

Anyone else with a vmax notice what appears to be a miss while slowly accelerating at cruising speeds? It seems to happen between 1500 and 2000 rpms while cruising in OD. Also seems to be worse when running the AC.

skp05 · August 20, 2008

Anyone else with a vmax notice what appears to be a miss while slowly accelerating at cruising speeds? It seems to happen between 1500 and 2000 rpms while cruising in OD. Also seems to be worse when running the AC.

Yep, I have it also. It's real bad when under a load. Pulling a trailer it's really bad.

The engine really surges at that RPM.

I would be curious if there was a service bull. on it. (I know, you can't share it with me, but maybe there is a "re-flash" for It out there)

svensk · August 20, 2008

Mine does that once in a while pretty badly, but it's not a vmax engine. Mine is probably due to an intake gasket leak.

99silverado1500 · August 21, 2008

Mine does that once in a while pretty badly, but it's not a vmax engine. Mine is probably due to an intake gasket leak.

Im pretty sure I have the same issue as well.

jdg2 · September 24, 2008

Anybody else have any info. on this issue? GM techs, engineers, parts people, tuners. It is the only real gripe I have about my truck right now . One of the mechanics at the dealership I bought at has a vmax with the same issue and he hasn't figured it out yet either.

Kanima · September 24, 2008

Mine too, but change to 93 OCT and see what happens. Mine cleared up, so after a while couple of tanks i went back to 87 and it came back. That is my best guess on it currently.

GMCrazy777 · September 24, 2008

i thought all 6.0 engines only ran high test fuel?

Kanima · September 25, 2008

Nope book doesn't say it requires 93 so go figure.

jdg2 · September 25, 2008

i thought all 6.0 engines only ran high test fuel?

I've run nothing but 87 octane in mine since I got it in June. I had Justin do my tune based on using 87. I know I would get a lot better performance from 91 or 93 but my VMAX runs ok on 87 (for now).

jdg2 · July 7, 2009

Anyone else with a vmax notice what appears to be a miss while slowly accelerating at cruising speeds or trying to maintain speed on a slight grade? It seems to happen between 1500 and 2000 rpms while cruising in OD. Also seems to be worse when running the AC.

Just thought I would bring this up again and see if anyone has anything to add from almost a year ago. My truck still has the same problem and I have not found a cure.

hockeypro1411 · July 8, 2009

I don't have the VMAX, but my 6.0 starts misfiring and flashing CEL's while on the highway at about 65 mph and a constant 2600 rpm's. The mechanic from the dealership said it was plugs n wires.

jdg2 · July 8, 2009

Anyone else with a vmax notice what appears to be a miss while slowly accelerating at cruising speeds or trying to maintain speed on a slight grade? It seems to happen between 1500 and 2000 rpms while cruising in OD. Also seems to be worse when running the AC.

Just thought I would bring this up again and see if anyone has anything to add from almost a year ago. My truck still has the same problem and I have not found a cure.

Well I'm glad nobody else has this problem, but It sucks that I'm the one that does have it. Tried the dealership once already for a fix, guess I'll try again.

Stevens03 · July 8, 2009

Stay on them... I would keep bringing it back till your satisfied. I makes me mad when dealers use the phrase "Normal condition" or "Cant reproduce the issue" Just means they didn't look close enough. Not all dealerships do that, but anyone that's had service done has heard one of those phrases. I'm just glad I don't have all these little issues with mine.

Only issue I've had in 30,000 miles was the rear-main seal and trans seal. But I heard that was pretty typical of the GMT-900's so I'm not worried about it.

skp05 · July 8, 2009

I still have it also. I haven't been to the dealer for anything yet. Although, I should take it in for the heated washer fluid stupid thingy.

Anyone else with a vmax notice what appears to be a miss while slowly accelerating at cruising speeds or trying to maintain speed on a slight grade? It seems to happen between 1500 and 2000 rpms while cruising in OD. Also seems to be worse when running the AC.

Just thought I would bring this up again and see if anyone has anything to add from almost a year ago. My truck still has the same problem and I have not found a cure.

Well I'm glad nobody else has this problem, but It sucks that I'm the one that does have it. Tried the dealership once already for a fix, guess I'll try again.

jdg2 · July 8, 2009

I still have it also. I haven't been to the dealer for anything yet. Although, I should take it in for the heated washer fluid stupid thingy.

Anyone else with a vmax notice what appears to be a miss while slowly accelerating at cruising speeds or trying to maintain speed on a slight grade? It seems to happen between 1500 and 2000 rpms while cruising in OD. Also seems to be worse when running the AC.

Just thought I would bring this up again and see if anyone has anything to add from almost a year ago. My truck still has the same problem and I have not found a cure.

Well I'm glad nobody else has this problem, but It sucks that I'm the one that does have it. Tried the dealership once already for a fix, guess I'll try again.

I have yet to go back to the dealer for any service either. That's a good thing. I may have to give in though just to get this looked at. I know one of the mechanics there and he has the same truck with same issue and has not figured anything out yet.