Oldsmobile Achieva Shudders and Shakes

touchton

Hi,

My 1992 Olds Achieva begins shuddering over 45mph
and continues all the way up to about 70. Seems
worse when the torque converter clutch is locked
up. Doesn't really show up in the steering wheel,
just feels as if the whole car is moving or
"bucking" slightly. Anyone else experience this
and know what causes? Dealer drove it and said it
runs great.

Thanks

poisondartfrog

Don't know what your mileage is, but it may be a defective TCCS (torque converter clutch solenoid), which is a common problem on GM FWD trannys. Usually, the symptom is the TCCS doesn't un-lock the torque converter, and the engine dies when you come to a stop, since the engine is still loaded by the driveline. If you are so inclined, you can disconnect the TCCS connector, it's usually near the torque converter/bellhousing, and see if the car still shudders. You'll notice with the TCCS disconnected, the engine will be revving higher at a given speed over 45 mph, since the torque converter remains un-locked.

That's my first pass at your problem...

touchton

Thanks for the response.

The car has about 95,000 miles on it, and runs great except for the shudder. The TCC seems to lock and unlock just fine. If I get it to unlock at 45mph or so, the shudder seems to go away. I do have some other shakes that might be wheel balance or CV joints?

Definetly does seem like something is amiss when the TCC is locked. Doesn't quite seem like an engine miss.

Car has been doing this since about 70,000 miles. It has not gotten worse since then, just stayed the same. 3 dealers were unable to determine what is wrong.

Appreciate any help you may offer.


One other thing... how does one know when it is time to replace the CV joints/front axle assemblies??


Thanks,

Scott

poisondartfrog

Does the shudder appear at the same road speed if you shift down one gear (a little kinder on engine revs at 70 mph with 4-spd vs. the 3-spd tranny!) If it does, then you would look at problem areas from the transaxle output to the wheels.

On my '84 Skyhawk FWD, I just replaced a hub/bearing and the CV axle. I had a thumping noise that turned out to be the hub/bearing; When I had the front end on jackstands, I first checked for bearing play side-to-side and in-and-out, but there was none. I then put the tranny in neutral, and spun the wheel... I heard a faint noise from the hub, and felt little roughness from the CV joint. I re-checked the joints by turning the wheel full left and then full right, rotating the wheel each time. I determined one outboard CV joint was bad, and replaced the entire axle assembly for $100 (Pep Boys). The hardest part was popping out the lower ball joint, which lowers the lower control arm, and gives you the clearance to pull the axle out of the transaxle.

I noticed immediately with the new axle that the car turned easier, which makes sense. From what I'm told, 100K for a CV joint/axle is pretty good.

Another possibility is tranny fluid level and condition... when was the fluild/filter last changed?

Wheel balance would be another easy check...

Good luck!

touchton

I seem to have two different "shudders" going on.

One is definetly under load (drivetrain). If I downshift the car, the TCC unlocks and the engine revs and that shudder goes away. I think this is similar to your recommendation to downshift.

I think I do have something screwy with a tire. Been getting rebalanced every six months, and one has a ton of weight on it. The place where I bought the tires said the rim was bent. Everyone else who has balanced it felt the rim is OK. I'm not sure what to do with it... about ready for new tires anyway so I thought I'd try that first.

Is there a good way to check for a bent rim besides throwing it on the spin balancer and looking for a wobble?

The tranny was flushed and filter changed at aroung 65K miles. Shudder existed before and after this.


One new development that might be related? Last night in heavy rain I drove the car through some small puddles (it's the wifes's car.. I don't drive it too often) and noticed that the car REALLY pulls to the side that the puddle is on. These weren't big puddles either.


Thanks for all the input so far.

poisondartfrog

No matter if the tire is balance, the bent rim, the tire, and possibly the hub/bearing may be bad. The spin balance is good only up to a road speed of 50-60, if I recall.

A wheel may not start to hit a wobble frequency until 70 mph. Whatever caused the bent rim, pothole???, the tire damage may be internal, as in a shifted belt, which is very tough to diagnose, but certainly is the most probable cause of the shudder. In addition, the bearing balls and race in the hub/bearing assembly may have been flat-spotted from the impact that caused the bent rim.

My advice? New rim and new tires. Get a name brand tire too. The cheap tires are not molded with as tight a tolerance as speed-rated tire, as in a H-rated tire, for example, so more balance weights are needed and the chance for imbalance at higher speed goes up. If it's a steel rim, you can get one pretty cheap at TireRack http://www.tirerack.com. Probably $35.00 or so. If it's an alloy rim, look either at a junk yard, or http://www.aaarims.com typically has overstock sale rims for GM FWD vehicles. Once the rim and tire are replaced, drive it at 70. If the shudder is still there, I'd check the hub/bearing.

In regards to the puddle, the tires must be low on thread-depth... even a small anount of water can make a worn tire hydroplane, where it temporarily loses contact with the road, which is the pull you felt.

Glad to help.

poisondartfrog

Outside chance a warped brake rotor could also cause a problem. See Topic #1236.

touchton

I did have good? tires on the car (BfGoodrich Comp t/a). But one tire seemed to always need balancing.

I will be putting new tires on the car this week, so I'll let you know what happens. The tire place said they can check the rim while it is on the spin balancer. Do you think this is an OK way to check it? I figured you would need a dial indicator to see if the runout is in spec. They seemed to imply you can visually watch it.

The car has new rotors (the original ones warped within the first 40K miles).

It has one new front wheel bearing. I was thinking of replacing the other, the shocks, both axle assemblies and the rear bearings. Figured I should start with the tires and rim first.

Thanks again for you help

touchton

Still planning on putting new tires on this week, but I noticed something new this morning. When driving at about 5 to 10mph, the steering wheel rocks back and forth about 1 inch. As you speed up, the rate of the rocking increases. Over about 25mph you can't detect it. Do you think this is related to the "shudder" issues??

Also... I was leaning towards Firestone Supreme SI tires. Any feedback as to this choice? Price seems right, $70 mounted. I plan on driving the car only part of the year to give my truck a break until the snow season arrives.

touchton

Due to the recent flak over Firestone, and their past history I decided to put Dunlops on the vehicle instead.

poisondartfrog

Happen to a co-worker's '99 300M... rotors were warped, and with 30K on the replacement rotors, it is entirely possible it is happening again. It's a good idea to always buy new rotors, especially on these GM FWDs... machined rotors are thinner and more prone to warp since there is less metal (mass) to shed the heat from braking.

Also, if it is warped rotors, make sure the rear brakes are functioning and adjusted properly, as poor rear brakes force the fronts to do all the work.

So I'd start with the new tires, get an unbent rim, and check the rotors.

touchton

I think you might be right about the rotors. Been noticing a shimmy while braking and recently the backs needed some serious adjusting.


Thanks again for your input.

poisondartfrog

Any updates?

touchton

Taking the car for service tomorrow. New tires, having the rims checked, etc. I tried loading the car in drive with the brake applied and noticed a shudder. Going to ask the service department to check it out.

After this is done, I'm going to check into the rotors.

I'll let you know whats found.

tjmeyers

Does your car shudder while driving on the same road and at the same exact spot of that road? If so, I would contact your local highway department and have them repave that section of the road. (heh! heh! heh! nothing like a little road humor to help cheer up car problems)

lala8

hi---i was just surfing the net and came across this conversation. I have a '94 acheiva and guess what!!! Mine is shaking too. It has about 112,000 miles and has been doing it a long time and now it stalls every once in a while. I've had the thing hooked up to a diagnostic computer they can't find anything. I have also changed the tires, brakes are fine, replaced axles/cv joints, ball bearings are good, several people have driven my car and wouldn't you know it---it ran fine for them. First the shuddering appeared at 60 mph, then 70 mph. As time went by it began shuddering at 50 mph and now 40. I love my car, but am about at my wits end with it! I am reluctant to take it on trips--this is my only car so I have no option. The last trip I took was only a few hours drive and by the time I got to my sister's house--my final destination--it was not wanting to shift into gear at all. what is this TCC that y'all were talking about and where is it located? PLEASE HELP ME!!!!!!! Oh yeah---all of the fluids are topped off--I check them regularly. What 's the possiblity of a bad tranny? I have done everything I could possible think of to do---except change the transmission. Some one please respond!!!!!!

robgm94

I have had my 94 acheiva for a while and I've experienced this shimmy as well. In the shop I've had quite a few similar complaints. check the lower control arm bushing. We were checking balljoints on a few of these and the bushing poped right out!!! This could be the reason for the shimmy. Stalling and missing is a common problem on these vehicles caused by arcing at thie coil. You can not replace this spark plug boots. you have to buy the whole new overhead modual/coil. About the tcc, you probably screwed yourself on that one. You can top off fluids all you want, but that doesn't flush the system. I'm guessing its too late to change the fluid in the pan and torque converter and filter which should be done every 30,000 miles. Wear from 112,000 miles on the same fluid can cause miss aligned gears or even lock a tcc.If your trans. hasn't already gone you should change the fluid. It may not solve your problem, but it will prolong the life of a dying tranny.

touchton

Well, its solved.
To start... tires had shifting belts... new Dunlops fixed all of the shudders not associated with engine load.

As for the miss under load, new EXPENSIVE spark plug wires totally fixed the problem. New CHEAP wires did not. Moral of the story... buy factory original wires... I wish I did.

jschmitz1

alcan

Yep, a few dozen of them.

jschmitz1

Where is the solenoid located? It is my understanding that the solenoid is located under the valve body cover. True?

alcan

What year is your Achieva? They have as many as 4 solenoids and a force motor. BTW, why are you changing the TCC solenoid?

jschmitz1

My Achieva is a 91 model, and it was diagnosed by the local dealership as having a bad torque converter control solenoid. It exhibits all the common symptoms, stalling at stop lights, starting in neutral but dying when placed in drive, etc. After researching it, I'm fairly certain this is the problem. Your recommendation?

brianhartepi

I have a 94 Achieva with 70k miles that generally runs great, but at highway speeds, the car tends to stutter and vibrate itermittently. I don't think it's the tires or suspension. When I put on cruise control, the problem gets worse. At lower speeds it seems to be fine, but on the highway, about once or twice a minute, I get 3-5 seconds of stuttering or misfire type vibration. Any ideas?

linet113

the first thing that happened was i was driving down the street it started to shake a little so i pulled into a parking lot and it stalled out. i started it again, it would start but when i put it in to gear it would stall out. so when i didnt put in gear the engine would shake really bad. but now it won't start. so im getting a new starter for it. ive checked the fuel system they said it was fine.resently ive put in a new battery and i tried to start it again and a little smoke came out of the engine. please help me figure out what is wrong please! thank you roxane.

assman97

Hello everyone. I'm not a mechanic, but I am very mechanically inclined, do all my automotive work myself, and am very good with computers as well (ie. car computer systems). So here goes:

Shakes/Shudders --> Most engine caused shakes will occur as soon as the overdrive torque converter kicks in at a speed of about 45 mph (80 km/h). This does not mean that they do not occur at other speeds in other gears, but due to the nature of an automatic transmission, the fluid absorbs most engine power irregularities. When the converter kicks in, the auto tranny is "bypassed" and the car becomes like a manual if you will. Therefore, you will feel any shudders from the engine. As for the cause, most people mistake it for the torque converter solonoid or something to that effect. In fact, it is usually the electronic ignition system. Check the ignition control module, electronic distributor, wires, plugs, and all associated sensors as well. A diagnostic check will help. And check for a miss under a load as well.

Stalling--> Most stalling (especially as soon as the car is put in gear is caused by faulty sensors (oxygen sensor, mass airflow, idle/air control sensor, etc.) or control units such as the ICM (ignition control module) or the ECM (engine control module). Also, mechanical failures such as the EGR valve siezing are common as well. Have these checked and also have the fuel rail pressure monitored after the engine is shutdown as well to check for faulty injectors.

Let me know how you do with your problems. Good luck!

glkman

I have a 96 Acheiva sc 2door coup. I have a three year son whoes car seat sits in the back. I set the car seat in the center of the rear seat. The problem I have is getting the car seat to stay snug. I have tried to adjust the seat belt many times, but I cant seem to get it to stay snug. Does any body know if AM has any information out on instaling child car seats? Thank you for any information?

assman97

Be sure to use a tether strap anchor to fasten the child seat to the rear shelf using a dealer supplied kit. This will ensure that the seat does not move during a collision.