Bad Vibrations, Especially From Idle To Around 2500rpm

I Have This Problem With My 96 Gxe Altima. The Car Vibrates Alot, Even In Nuetral. It Vibrates So Bad That It Makes Its Way All The Way Into The Cabin (i Guess Thats Obivious) But Getting To The Point, The Car Has All New Motor Mounts As Well As The Transmission Mount, New Spark Plugs And Ignition Wires, Alternator, Battery, Igniton Rotor And Distributor Cap, The Car Runs With 10w 40 Oil, And Gas Mileage Is About 23mpg In The City. Does Anyone Know What Can Be Causing This. Oh, Yeah The Idle Is Approx 700 To 750

Does it vibrate when the car isn't moving? Does it vibrate when you are decellerating? How long has it been vibrating or when did the problem begin? Manual or auto trans? Has the transmission ever been removed? SAE 5W-30 viscosity oil is preferred for all ambient temperatures and benefits fuel mileage. Sparkplug wires out of sequence is a possibility. Clutch assembly can be out of balance and vibrate as can a torque converter.

first off, thanks alot for responding (justsaygo), I did some work to the car, including replaced the transmisson mount and replace the sway bar link, which had broken, replace 1 drive axle and air filter. Since this service things seem to be alot better. Currently I'm using 10w 40 oil in the car. Its so intresting that you mentioned that 5w 30 is the best to use, because I was just considering wether I used switch to mobil 1 5w 30. The question is, Will 5w 30 oil provide sufficeint lubrication on an engine with 134 thousand miles. Additionaly theres one other problem that has me worried, perhaps you can help. when I'm traveling on the freeway, around 60 mph or more, whenever I'm on anything but smooth pavement, the front right tire makes a thumping sound when it hits a bump. It almost make you think that you are rolling on a flat tire (thats how pronounced it is) however the tires are brand new (215/65r15). In addition to this, the body of the car jirates from left to right, bobs and just in general dosent feel plated down when at speed. Ive visually checked the suspention, and can't seem to find any obvious probs. PLEASE HELP. Thanks alot in advance, by the way, I have an automatic trans, and the transmission has not been removed to my knowledge, I just recently bought the car about 7, 000 miles ago.

If the vibration problem is much better, the axle must have been the problem. Was the vibration only with the car moving? You may have a damaged strut on the side that goes thud on the bumps. Any vibration would transfer more through a strut that is binding. The struts also have insulators designed to dampen vibrations that deteriorate and allow vibrations to transfer into the body. Engines have changed over the past 30 years and so has motor oil and lubrication requirements. One of the most significant changes is fuel injection which reduces fuel dilution of the motor oil. Fuel dilution gradually reduces viscosity during the oil change interval. Motor oil is formulated to get a little thicker during the oil change interval to compensate for average fuel dilution that thins the oil. The 5W-30 words are copied from the last page in my 97 owners manual. I trust the Nissan engineers and believe in the advantages of lower viscosity which include reduced engine wear. If your 96 is similar to my early 97 with 121,000 mi, the engine probably doesn't use or lose any oil. I have seen the inside of many fuel injected era engines with 200,000 mi and there isn't any wear that needs to be compensated. I like everything about Mobil I except the cost which is growing less significant as motor oil prices increase. Higher octane fuel isn't cleaner than regular. Fuel injectors don't need to be cleaned... ever, and changing oil every 3,000 mi benefits JiffyLube and their competitors far more than any benefit of extending engine life. Nissan doesn't say change motor oil and filter every 7,500 mi so that engines will wear out prematurely. Alignment is important. The wear on your old tires will tell a story. If the front wheels are toed in, and the body rolls slightly to one side as you drive or move the steering wheel, wieght is removed from one tire and transfered to the other. The car will steer or pull in the direction of the tire with the most weight which causes the body to roll a little more. Have you felt how the rear suspension also steers as the body rolls when turning a corner. There are times on the freeway that I feel the same very slight handling characteristics you describe. Maybe your car is a little more out of alignment? A binding strut will drasticly effect weight transfer. Wind turbulence seems to intensify the problem which seems not to be as noticable above 70 MPH.

Just want to say thanks for replying to my message so promptly, I'm going to look into those areas you mentioned, and I'll keep you posted, once again, thanks alot you've been a great help. till next chat

Hey, I Got Another Question For You. I Was Reading Some Of The Other Messages On This Forum. Particularly The Messages Dealing With Fuel Economy. A Couple People Stated That Their Cars Were Getting Very Poor Fuel Economy (somewhere In The 15 Mpg) Area. They Said That Their Mechanics Discovered That The Engine Was Dumping In Much More Fuel Than Needed (1 Person Said 4 Times As Much) Than Was Neccessary. However The Mechanic Was Also Was Able To Perform Some Kind Of Adjustment That Took Care Of The Problem. Do You Know Of Problem Like This, And If So What Could Cause Such A Thing. My Guess Is Possibly Bad O2 Sensors. This Concerns Me Because My Mpg Is Like 15 Mpg, Thats A Super Charged Enzo Ferrari Gas Mileage. By The Way I Recently Put 5w-30 Mobil 1 15,000 Mile Oil In The Car.