Nissan Titan Forum banner
1 - 20 of 21 Posts

·
Registered
Joined
·
6,067 Posts
Discussion Starter · #1 ·
I have a 96 Olds Cutlass Ciera Sedan 3.1L V6 front wheel drive with 86k on the odometer. It's my daily driver. I've been noticing a strange noise/thumping sound lately though. It's definitely something in the front end. I'll try my best to describe the symptom.

It's a thump, thump, thump, thump, etc... quickly. faster you're moving the faster it thumps.

Doesn't occur during acceleration.

Does occur during braking, but can't be felt in the pedal. Pads were replaced about 10k ago. Master Cylinder is filled correctly with fluid.

Does occur when coasting at a speed less than 40 mph +/-

Does occur when the throttle is applied, but not accelerating, just maintaining a constant speed. Especially at slower speeds 15-25 mph. Only occurs at speeds less than 40 mph.

Haven't had a chance to wiggle the wheels or pull them off to look at things yet.

Thanks for whatever suggestions/thoughts/comments you have.
 

·
Registered
Joined
·
686 Posts
Check the CV's, motormounts, and torque mount.
 

·
Registered
Joined
·
184 Posts
Check the CV joints.
 

·
Super Moderator
Joined
·
162,263 Posts
Ditto the above. Most of the time when the CV joints are going out, you can feel it through the steering wheel when turning, and it's usually louder then too.
 

·
Registered
Joined
·
121 Posts
Loose lugnuts can allow the wheel to move and cause a thumping noise. The CV joints can also be a suspect, but that would make more of a clicking noise.
 

·
Registered
Joined
·
2,955 Posts
I say it's the struts.
I had a Chevy Lumina, and the struts 'clunked' all the time.
I took it to the dealer and they said it was normal to hear them, probably due to the design or quality.

I drove the car till it had over 127K miles, and the struts held up-never had them replaced. Tires wore normal, no early wear on suspension parts- I just got used to the noise.

BTW-With the 3.1, watch the plenum gasket. They're notorious for failure, allowing water to mix with oil. Otherwise, the engine should last.
 

·
Registered
Joined
·
6,373 Posts
First let me be the first to welcome you to CutlassTalk...

You might want to search thru the CutlassTalk suspension/steering forum.

You also need to get that fine Oldsmobile on a rack ASAP to check most of what the others are suggesting.
CV's, axle shafts, hub bearings, and finally the tires themselves...basicly everything up front that turns.
 

·
Premium Member
Joined
·
141,094 Posts
The tires aren't coming apart are they?
YOu know, like a bump or blister on the road surface?
 

·
Registered
Joined
·
6,067 Posts
Discussion Starter · #10 ·
Well, I look things over last night.

Tires appear to be wearing normally, no blisters or belts showing
Wheel bearings are fine, no slop at all. Wheels spin freely.
CV shafts appear to be fine as well. No slop in them at all. Boots are in tact.
Lug nuts are tight
Steering components are all tight and greased.

I found three motor/trans mounts, but how and the heck are you supposed to tell if that's bad? Jam a pry bar in there and try jacking the motor/trans around? They were all solid.

It's gonna cost me $50 ea for new struts, might be worth replacing them. If I bounce on the front fender the car sits there and goes up and down and up and down awhile before coming to a rest!!! I've thought that the struts have needed replacing for quite awhile, but never thought they'd make a sound like this.

A co-worker stated that it might be the torque converter, considering that it does it when I let off the gas??


Thanks for the help
 

·
Registered
Joined
·
2,955 Posts
I still say struts. You're describing the exact 'symptoms' my car displayed. I noticed the sound, and it bothered me till I figured it out. After that, not a worry in the world.

Try driving over a speed bump at low speeds (20mph), and see if you don't hear the clunk. Or drive along, with no one around, then hit the brakes kind of hard, and see if the nose doesn't dive, and upon return, you'll hear the clunk.
Either way, good luck!
 

·
Premium Member
Joined
·
92,554 Posts
Letting off the gas and hearing something doesn't always mean tranny or drivetrain. You're shifting the weight distribution of the vehicle when you accelerate, coast, or brake. So yes, it could very well be a suspension component.

If it doesn't stabilize almost immediately, and bounces, then it does sound like time for new struts. If you have a shop do this, check under there while it's apart, and chum up to the mechanic while he's doing it and ask if he sees anything else that needs attention. Most of them are more than willing to educate someone who knows more than nothing about cars. They don't care much for total car idjits, but people who ask intelligent questions are typically welcome.
 

·
Premium Member
Joined
·
141,094 Posts
Those 3.1's do have a tendency to need motor mounts.
 

·
Registered
Joined
·
6,067 Posts
Discussion Starter · #14 ·
If I decide to replace the struts, I'll be doing that myself BB. Might be tomorrow's project.

A motor mount would probably be a beeotch for me to replace here in the apartment parking lot though. If I were back home, not a problem, but I'm not taking my car on a 500mi round trip just to replace a MM. How can I check the motor mounts to see if that's it. I don't like paying the mechanics to do any more than is necessary, including diagnosing the problem.
 

·
Premium Member
Joined
·
141,094 Posts
If you have a a lift to put the car on, it really helps on those.
Have a helper start the car, put it in gear, hold the brake, and romp the motor. Safely observe to see if the motor is torqueing over.
 

·
Registered
Joined
·
6,067 Posts
Discussion Starter · #16 ·
LOL, lift, bwaahhaaahaaaaaaa. I feel fortunate to have a level, paved surface to work on, as opposed to working in a bumpy gravel driveway like I'd grown used too!!!
 

·
Registered
Joined
·
6,067 Posts
Discussion Starter · #17 ·
Ok, so I've noticed that it only does it when traveling straight. With hand on the steering wheel, positioned at 12:00, a turn to either 11 or 1 will make the problem go away.

Any more thoughts given this new info?


My gut is telling me that it's not the struts.
 

·
Premium Member
Joined
·
92,554 Posts
Steering rack. That's got to be your next item. Especially since you've checked the CV joints and it's not them. Check the fluid. Many times the power steering hose will get a slow leak, and it only happens when you are driving, so you rarely leave a puddle. See if the fluid is low and if so, you may need to look at the steering pump or rack. Just my .02.....
 

·
Registered
Joined
·
257 Posts
i just finished changing the flexplate on my friends 99 Buick century. before i changed it there was a constant "knocking" sound. he brought it to the dealer i worked at the time and i had a used car tech look at it with a stethoscope probe and he said that is was rod knock, and that the engine might last 5 miles or 50,000 miles... one day he was coming hone from school, he stopped to get gas, left, went about a half mile and he said the car seems as though its in neutral... i was like wtf??? go there to pick him up and the flexplate broke where it bolts to the crank... after changing the flexplate it doesnt knock anymore. he has a 99 grand prix gtp and the buick is his winter beater. he is a member on a grand prix forum and when he did a search for flexplate, there are issues with the flexplates cracking and making a knocking sound. wouldent hurt to take off the inspection cover to the check the flexplate. the knock did go away with a little gas like 1,100 rps give or take, the buick dosent have a tach. and its sounded like someone was beating the sh*t out of a metal garbage can when he shut his car off before i fixed it.

i'm not saying this is your problem 100% but it wouldn't hurt to check your flexplate to see if it cracked.
 

·
Registered
Joined
·
6,067 Posts
Discussion Starter · #20 ·
Well, I just thought I'd post this update, as I'm certain that all of you have been losing much sleep over this!!!

The problem has been fixed. A wheel on the front was bent. I guess I've been doing too much rock-crawling!! I have no idea how it got bent, I noticed that the lip on the inside of the wheel was "dinged" a little bit, but I never would have guessed that it would have caused the problem that I was having. The mechanic (yes, I got frustrated and took it to a garage)explained to me that the rim was bent, which in turn caused the tire to get "pulled" "out of line" basically, which basically made it out of round. The sound that I was hearing- thump thump thump- was the caliper/bads banging around because of the wheel wobbling.

There was also a bad tire on the back as well, which had a bulge in it. I guess this is the price I pay for buying el cheapo tires. So when it was all said and done, I've got a new wheel, and two new tires. I had them put the new tires on the front for wintertime. There wen't a cool $175 that was in the "DR Coilovers Fund"....disappointing, to say the least.
 
1 - 20 of 21 Posts
Top