Tahoe bog around 45

[rcorbin]

I have a 2007 Tahoe with the 5.3 with 175k miles, I have noticed that the truck has been very sluggish around 45 if i try to accelerate its slow and it vibrates, until out of nowhere when i hit about 55 it just stops and everything is normal, i can also feel as i’m accelerating the engines rpm is slowly dropping down and then goes back up, almost like it’s misfiring, my truck isn’t throwing a code though, I have replaced the fuel pump, spark plugs, maf sensor and done a air filter recently, also checked the throttle body and it seemed clean. Also would like to add my transmission shifts normal and I am getting normal temperatures. Any suggestions on what it could be would help tremendously thank you.

 

[j91z28d1]

man that could be so many things.

do you have a scanner?

 

[rcorbin]

I do have a scanner but its a cheap one and doesnt show anything.

 

[swathdiver]

Is AFM still active? Sounds like your VLOM solenoids are getting lazy and what you are feeling is the truck slowly going in and out of V4 mode.

 

[j91z28d1]

Is AFM still active? Sounds like your VLOM solenoids are getting lazy and what you are feeling is the truck slowly going in and out of V4 mode.

very well could be and if so, afm probably isn't long for this world.

if the dash shows the v4/v8 could you watch that and see if they correlate?

 

[B-train]

Agreed with @swathdiver and @j91z28d1 on the AFM stuff. Have your tried driving it the same way in Manual mode? Forget top gear and just see how it runs when AFM isn't supposed to be active?

Just on the off chance, have you tried some good injector cleaner, or run any trans fluid or MMO in the oil the last 500 miles to see if it cleans anything up. Had good luck with both over the years for weird lifter/injector issues FWIW

 

[Ford 96 chevy 07]

I have a 2007 Tahoe with the 5.3 with 175k miles, I have noticed that the truck has been very sluggish around 45 if i try to accelerate its slow and it vibrates, until out of nowhere when i hit about 55 it just stops and everything is normal, i can also feel as i’m accelerating the engines rpm is slowly dropping down and then goes back up, almost like it’s misfiring, my truck isn’t throwing a code though, I have replaced the fuel pump, spark plugs, maf sensor and done a air filter recently, also checked the throttle body and it seemed clean. Also would like to add my transmission shifts normal and I am getting normal temperatures. Any suggestions on what it could be would help tremendously thank you.

Were you getting low oil pressure? Ours has no codes and is bogging down. The oil pressure has been saying low a few times and we add oil but this time it seems worse.