mentalattica
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- Oct 22, 2012
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Hi everyone I'm a new member here and have some questions about an issue that has been bugging me for months.
I have a completely stock 2007 GMC Yukon SLT 5.3 2WD with 58k mi.
It's hard to describe but my truck shakes/vibrates when I put it into reverse, it's at it's worst before the engine reaches operating temp. I can feel it in the steering wheel and brake pedal. It's not a violent shaking, but it is noticeable. If I put it in neutral, it's as smooth as butter. In park I can feel a little stumble/shudder every few seconds but it's really pronounced in reverse. There are no drivability issues, no power loss. It feels like a misfire if I had to describe it simply, but I don't think it's missing. No codes either.
It's been happening for months now and it drives me crazy.
So far this is what I've done:
*Plugs & Wires (oem)
*I've been through a couple cans of techron and sea foam
*Pulled the throttle body off and cleaned it real well (the back of the plate was covered in oil, is that even normal???)
*Oil Change, I've always used Mobil1 syn
*Trans fluid change
*Swapped back to stock intake (had Spectre short ram)
*Cleaned MAF
*Checked for vac leaks, can't find any.
*Took it to dealer and they couldn't reproduce (it didn't sit long enough in my opinion to cool back off)
**Just checked trans fluid, it was a little low, just below the first hot hole in the dipstick. I added 1/2 quart and it's at the first hole now.
The most recent repair was a new brake booster and master cylinder, but it was happening before that.
Tried to clean IAC and EGR but I can't find them, do 2007+ 5.3s have them?
I'm at a loss now. The only other thing I can think of is mounts but it really doesn't feel like a bad mount. There's not much play in the engine at all, no clunking at all either. I think it's engine related because after it reaches normal operating temps it's hardly noticeable.
If it is a mount, would being it being in reverse indicate that it's the driver's side mount? Any other ideas anyone?
I have a completely stock 2007 GMC Yukon SLT 5.3 2WD with 58k mi.
It's hard to describe but my truck shakes/vibrates when I put it into reverse, it's at it's worst before the engine reaches operating temp. I can feel it in the steering wheel and brake pedal. It's not a violent shaking, but it is noticeable. If I put it in neutral, it's as smooth as butter. In park I can feel a little stumble/shudder every few seconds but it's really pronounced in reverse. There are no drivability issues, no power loss. It feels like a misfire if I had to describe it simply, but I don't think it's missing. No codes either.
It's been happening for months now and it drives me crazy.
So far this is what I've done:
*Plugs & Wires (oem)
*I've been through a couple cans of techron and sea foam
*Pulled the throttle body off and cleaned it real well (the back of the plate was covered in oil, is that even normal???)
*Oil Change, I've always used Mobil1 syn
*Trans fluid change
*Swapped back to stock intake (had Spectre short ram)
*Cleaned MAF
*Checked for vac leaks, can't find any.
*Took it to dealer and they couldn't reproduce (it didn't sit long enough in my opinion to cool back off)
**Just checked trans fluid, it was a little low, just below the first hot hole in the dipstick. I added 1/2 quart and it's at the first hole now.
The most recent repair was a new brake booster and master cylinder, but it was happening before that.
Tried to clean IAC and EGR but I can't find them, do 2007+ 5.3s have them?
I'm at a loss now. The only other thing I can think of is mounts but it really doesn't feel like a bad mount. There's not much play in the engine at all, no clunking at all either. I think it's engine related because after it reaches normal operating temps it's hardly noticeable.
If it is a mount, would being it being in reverse indicate that it's the driver's side mount? Any other ideas anyone?
