Need help somethings wrong

[992door]

I need help!!!! I dont know if i have asked this before in here but. When driving down the road if i give it medium to heavy throttle when it gets to around 55-60 it just starts shaking violently (sp?) so much that i have to get of the throttle and it feels like it has lost alot of power. BUT when i let off the throttle i can not feel it doing it anymore. SO i let it slow down until about 50 or so and it i get back on the throttle REALLY light it will go past 55-60 without doing it. I thought it might be missing but i has not thrown any codes of any sort. It has been doing this for a little over a year but before it would only do it at like 70 and i would never go 70 so i would forget about it. HELP!! it is getting anoying

 

[COTahoeLS]

Wheel balancing?

 

[992door]

dont know why i put this in this section. it is fine

 

[MikeTheApeman]

Jeebus, I was having flashbacks to Jeeps Unlimited, cause that's sounds a heck of a lot like Death Wobble!

 

[992door]

if it was that wouldn't i feel it in the steering wheel

 

[MikeTheApeman]

not all the time, some guys claimed their wheel was fine.

 

[992door]

i feel it in the seat more than anything

 

[NoChrome]

Have you checked your egr valve? A buddy had an explorer that did the same thing, egr was nasty. Good luck.

 

[992door]

no i havent but i will

 

[992door]

anyone else have any input????

 

[NoChrome]

The only other thing I could think of wold be a pcv valve... good luck.

 

[dec322]

I would start at wheel balancing. Mine had the same type of problem at around 45-55. If I was slowly gaining speed it would vibrate around this area. If I had my pedal down hard it would blow through that range without any problems. I had an alignment done and had the wheels balanced (time for new tires) and it was fine.


To confirm that it could be wheels I will talk about my 89 cutlass calais. One time I drove it through a mud path....well, I drove it through the path over and over again until the whole car was covered in mud. On the way home I got it up to around 45 mph and it vibrated so bad that I feared taking it over that speed. Ended up being mud in the wheels that caused it to be out of balance.

Point of the story is that the more out of balance it is the worse the vibration. I didn't feel it in the steering at all.

 

[hyde]

Check u joint on drive shaft and or check the rear bolts on the drive shaft....I wouldnt think it was motor related cause it doesnt do it at all speeds. U joints and loose bolts do the exact discription of what you are talking about.

 

[DarkTahoe00]

Check u joint on drive shaft and or check the rear bolts on the drive shaft....I wouldnt think it was motor related cause it doesnt do it at all speeds. U joints and loose bolts do the exact discription of what you are talking about.

I agree check the U Joints I had one that was bad that caused a very similar vibration at certain speeds!