2001 lesabre - shake when accelerating

[BumpinBuick]

alright fellas, need to pick your brains.

2001 lesabre, around 107k miles.

Car has a "shake" or "shimmy" when accelerating, and it gets worse when there's more people or gear in the car.

I notice it the most between 10 and 40 mph. There is some goofy stuff that happens at highway speeds but i suspect that those shakes and shimmies have more to do with poorly balanced tires and a worn out suspension than anything else.

Anyways, i'm looking for some insight here. No codes, and the only sensor I know of that's bad is the oil pressure sensor (it always reads 130 psi on the gauge cluster).

I've had the proper 100k service done including trans flush, coolant flush, fuel filter, injectors cleaned, etc. I'm halfway done with plugs and wires (still need another nice weekend to do the back 3).

Any thoughts?

 

[HotZ28]

I think if you used quality wires & plugs on the front & back, that the problem should be eliminated. Secondary ignition misfire can cause all kinds of shudder, shakes & shimmies. Weight/Load does make a difference.

 

[BumpinBuick]

I think if you used quality wires & plugs on the front & back, that the problem should be eliminated. Secondary ignition misfire can cause all kinks of shudder, shakes & shimmies. Weight/Load does make a difference.

thanks. i used some fancy bosch spark plugs and bosch wires.

apparently it's noteable that both of my half-shafts are aftermarket. i've been doing some googling and it seems like lots of people have these sorts of issues with crappy aftermarket cv joints.

 

[HotZ28]

China built CV joints may be a possibility, but not likely within 10-K miles. In addition "Bosch" wires & platinum plugs are not recommended for the DIS ignition. (Too much resistance)

 

[BumpinBuick]

China built CV joints may be a possibility, but not likely within 10-K miles. In addition "Bosch" wires & platinum plugs are not recommended for the DIS ignition. (Too much resistance)

ouch! did not know that. Any idea how I will know that they're not functioning properly?

i'd say both of my china CV joints have closer to 20k on them but i'm hoping the plugs and wires/02 sensor (i'll be removing it for the plugs/wires anyways so why not replace) will fix the issue.

 

[Milehighassassin]

Start with taking off your wheels and tires and cleaning the inside. Through winter they buildup crud taking the balance out of spec.

If that doesn't correct it have them balanced at a good tire shop.

This has nothing to do with the motor. It might have a separate problem but the shimmy is from the tires and or suspension.

 

[BumpinBuick]

Start with taking off your wheels and tires and cleaning the inside. Through winter they buildup crud taking the balance out of spec.

If that doesn't correct it have them balanced at a good tire shop.

This has nothing to do with the motor. It might have a separate problem but the shimmy is from the tires and or suspension.

the main reason that I don't believe this is a tire balance problem is that at low speeds, like 10-40 mph where I feel this the most, the problem completely disappears when I take my foot off the gas.

I'm fairly certain i do have a tire balance problem, but believe me i've been to several "professional" tire shops recently to have balancing done only to leave with what feels like a worse balance than I started with. (This within the last 1500 miles or so on the car). I think eventually i'll just shell out for a balance on one of those fancy balancing machines.

 

[polarzak]

Wheel balance problems are normally evident above 50 mph. I had a similar (although hard to tell over the "Internet) situation in our 2000, so for what it is worth, it turned out to be a miss from one coil. I have also read on several sites that if you have the 3.8 in that vehicle, you should never use anything but AC Delco plugs in it. Can't remember why. Anyway, just throwing this out.
Good luck.

 

[BumpinBuick]

bumping this up because I fixed the problem. It was indeed the driver's side half-shaft.

Moral of the story is, use oem replacement half shafts 😱

 

[BumpinBuick]

and......back up since the problem isn't completely gone.

With just me in the car, it's pretty well tamed, but add another 250 lbs of people and gear, and it's still there. I've decided to do other half-shaft, since it is also aftermarket. If that doesn't help i'm thinking motor mounts (front center is already new), and failing that front control arms/ball joints. Failing that, i'll either drop kick the car into a lake or take it to a mechanic.

 

[CasuallyAwesome]

Not to point out the obvious, and I'm sure you've always made sure of this, but are you sure you aren't just hydroplaning(spinning the wheels)? FF+ 230 lb-ft can get the best of you.
Because that sure sounds alot like it.
Cheers!

 

[BumpinBuick]

Not to point out the obvious, and I'm sure you've always made sure of this, but are you sure you aren't just hydroplaning(spinning the wheels)? FF+ 230 lb-ft can get the best of you.
Because that sure sounds alot like it.
Cheers!

that would be something!!

nah, I'm fairly certain the wheels aren't spinning. Definitely something for me to look at though.