step on the accelerator causes car to shake

[quadcells]

Hi All,
My 2000 Buick has issues. I just replaced the front struts, coil springs, sway-bar links, front right hub assembly, spark plugs and wires.
It seems to run great, but when I step on the gas the car shakes. Going down a big hill fast and the car is smooth, only stepping on the gas causes this car to shake. What could it be? I had the tires balanced and aligned.
/quadcells

 

[quadcells]

Hi again,
I was thinking it might be one of the motor munts.
I will try to check them when I get home.
Has anyone have any experience with motor mounts? Would they cause the car to shudder under hard acceleration?
Thanks
/quadcells

 

[Enslow]

Check your plugs and wires. This is an often overlooked item. I've even heard of new plugs/wires failing, especially non-OEM brand stuff.

My Lesabre did exactly the same, but was really smooth at idle and normal acceleration. If plugs and wires check out, then it may be one of the solenoids in the transmission. My next step would be a transmission oil/filter change.

 

[quadcells]

I will check the wires, funny you said that. I replaced the plugs and wires because the plug wire for #6 cylinder was broken and since replace it, I still have the shuddering.

 

[quadcells]

Hi Enslow,
You said that your Lesabre did the same thing. Was it your plugs or wires? Just woundering.

 

[quadcells]

Hi,
I just checked and my front motor mount is bad. Step on the gas in drive with the brake on and the engine looks like it will flip over. I am still going to check the wires.

 

[Enslow]

Yup, you'd better get onto that motor mount. When I did my wires (bought the car used from a Buick dealer), one wire was so badly rusted it broke off leaving the clip end on the plug. I don't know how the car ran so well when not under load (idling).

 

[StuMpy77]

Is the car actually misfiring? Given you only get the shake when accelerating (I assume it goes away as soon as you let off the gas), combined with the fact you replaced a wheel bearing/hub assembly leads me to believe you have a bad or worn CV axle. Fits the classic symptoms plus it's not uncommon when changing hub assemblies to slightly change geometry of the axle and have an axle go out shortly after. The slightly altered angle/distance to the new aftermarket hub causes the roller's in the tri-pot assembly in the axle to ride in a different location than it did before.

I am fairly certain you have a bad axle, could be either one(Passenger or driverside) but I'd inspect the one you did the hub assembly on first. This is of course assuming you have proper torque on the axle retaining nut and the 3 bolts that attach the hub assembly to the spindle. "They" say to replace the nut with a new one each time but I've never had a problem reusing axle nuts, though it should be mentioned it's not the approved way to do it, make your own informed decision. If one or the other started coming loose you may experience issues like this but I very much doubt it would go away when you let off the accelerator. I also doubt it has anything to do with the transmission itself assuming decent fluid quality and level. Check for play in the transaxle output bearings while your inspecting the axles, if it didn't do it before you did the work on it this shouldn't be an issue unless you have worse luck than I do lol. Hope this helps, best of luck!

 

[quadcells]

Hi StuMpy77,
It was doing this before I replaced the hub on the passenger’s side. But this is the third one in about 50,000 miles. I do replace the axle nut every time and I use a torque wrench (118lb). I m still waiting for the engine light to come back on, I had reset it after I replaced the plugs and wires (#6 cylinder wire was broken and I had a code that was for miss fire on cylinder 6). The front motor mount looks bad and when I had it in gear with the brake on and press the accelerator the engine seemed to move a lot. This is where I am now. Tonight I will check the wires again.
BTW: I checked the resistance of all the injectors and they all have the same readings and I also check the coils and the all have the same resistance and all producing a good spark.
Thanks again for everyone’s help so far.
One question about the cv axle, how do I inspect it? what am I looking for?
Thanks again.
/quadcells

 

[1380Ken]

What brand of hubs are you using. Three hubs in 50000 miles is not normal.

 

[quadcells]

First two where Timken, the lastest I just put in is Moog.

 

[quadcells]

Hi All,
Sunday morning I replaced the motor mount. The original was torn 3/4 around the bottom of the mount. Have not had it out on the road yet. I will be replaceing the LCA and CV axles this coming weekend.
I will get back to you all afterwards to let you know how it went.
BTW: Anything I need to know about removing the cv axles?
/quadcells

 

[quadcells]

Hi,
CV axle was the problem! After removing the driver's side cv axle I took it apart and saw that just about all grease was gone and rust all over the internal parts. So shaking gone (i did replce both cv axles). replced left & right LCA's, the front bushings of each arm were gone. When appling the brakes the car would make this noise that sounded like something was moving around, the LCA's fixed that. Still had the P0171 code coming up... that was a bad MAF sensor, replaced and engine runs great now.🙂
All that is left is to have the AC recharged, I replaced the AC compressor and dryer. Now it rides so nice!
/quadcells

 

[dsingleton]

my 2002 buick lesabre is doing the same thing i replaced the motor mont that was not the problem so im taking it back in in a few days

 

[timbo]

My 2000 had the same problem, cv axles fixed it

 

[G-545526]

I am dealing with similar problem 03 Buick century .. shakes and rattles when backing up and pulling out once past 35 it quits untill I come to a stop. Idles fine untill putinto gear then shaking starts again. Have replaced all selenoids in trans. Egr valve purge valve idle air control valve fuel injection pressure valve. Many upgrades and nothing has worked. Feels like it's missfiring or something like that. It's skippy and jumpy only at acceleration up to 30-35mph. After that runs and shifts fine. No shifting problems at all. Not transmission related I'm sure of it

 

[G-671447]

Just bought a 2012 buick enclave. I'm noticing at light acceleration there is a shudder. I will let off gas then push again and it will smooth out. It does it at different speeds. Any ideas of what this could be? I just purchased Saturday.

 

[Homer Jay]

Loose nut behind the wheel.

 

[Shawn Southard]

Hi All,
My 2000 Buick has issues. I just replaced the front struts, coil springs, sway-bar links, front right hub assembly, spark plugs and wires.
It seems to run great, but when I step on the gas the car shakes. Going down a big hill fast and the car is smooth, only stepping on the gas causes this car to shake. What could it be? I had the tires balanced and aligned.
/quadcells

I have a 2008 Buick Enclave cxl, I had a bunch of front end work done because my car shaked when I accelerated. Come to find out it was the torque converter between my transmission and engine.

 

[Jeff60_m]

Hello,
I believe I am having the same issue. Control arm bushings were bad and was having an ABS issue with front left wheel. Changed control
arms, wheel bearings, quick struts, sway links, outer tie rods. Same shutter under acceleration. Thought it seemed to be drivers side and changed that CV. Still have a whine and shutter. I have the other axle and will put it in. wheel alignment when all are completed is on tap. Although the wheel seems to be straight and no pulling. Also will check motor and tranny mounts and recheck inner ties. seems loose on wet roads/ heavy rain.
No codes for spark issues. Still dealing with rear air ride issues. pain in the ***.