Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 1999 Oldsmobile Alero owners, lightly cleaned up (personal details are redacted by NHTSA).
While driving driver noticed smoke coming under the hood. Pulled vehicle over and checked. Noticed coolant was leaking on the intake manifold. Took vehicle to dealership. Mechanic had not determine the cause of the leakage.
1999 Oldsmobile Alero (out of warranty) began to have problems with transmission "slipping" occasionally during the summer. I was told no problem could be found. While driving home last evening, the service engine soon light came on as well as the "trac off" light and it was very hard to get the car to go more than 30 MPH on a 50 MPH highway very nearly causing an accident. By the grace of god, that did not happen, but now I am told that the transmission May "possibly be bad" or it "could be several other things." in either case, it would seem to me that someone should have found the error before. Additionally, the car has less than 65,000 miles on it and though it was sluggish from the time I bought it and would occasionally lurch forward when pulling away from a stop, it was not until the summer that it became a frequent as opposed to a rare occurrence. …
At 50K miles, low coolant light would flicker on and off so per the manual dexcool/water mixture was added. This alleviated the problem only temporarily however. Light continued to come on, and later at 61K, oil leak was noticed on the side of the intake manifold. An appointment was made to bring the car to the dealership the same week, during which the security dummy light came on (for no apparent reason). Also during this week, the "change oil" dummy light came on 100 miles before the oil change was due (at 2900 miles). The car was brought to the dealership to fix per its appointment, and not only was coolant leaking into the engine, but the upper and lower intake manifold gaskets required replacement. In addition, on its way to the dealership, the engine started to misfire causing the "check engine" light to flash for several moments before turning to a steadily lit dummy light. …
I have had an 99' Oldsmobile Alero for 7 years. It has had almost every problem listed on this website. It has had an over heating problem every year since I got it and I have spent thousands in repairs for the cooling system, fuel pump, poor interior manufacturer, ac/heater blower motor settings failure, fuel gauge failure, transmission leakage, poor springs/struts, gear slipping, hard starting, water leaking in from rain under glove compartment, off alignment (set three times in year), poor gas mileage, overheating or running above normal temperature and sudden overheating without notice of gauge lights or sounds. Has had front right caliper failure locking brake pads down against rotor causing burnout of pads,rotor warping, caliper cylinder damage. Has had power steering pump leakage. …
My car's coolant light came on the first time about 2 weeks ago. At that time I replaced the coolant that was missing, only to have the light come on again 2 days later. I again replaced the coolant. I could not find any visible leaks under the car. I was driving to the mechanic when my check engine light came on, and the check coolant light came on. The cars tempature gauge was topped out. I had to pull over to the side of a major freeway and call for help. After 2 hours of waiting for a tow truck. The mechanic tells me that the upper and lower intake manifold gaskets need replaced. Also, the coolant had leaked into my engine and mixed with the oil causing the engine to miss. I had to have the gaskets replaced with a new version. And also have the engine flushed, an oil change and a coolant flush as well as a coolant change. All of this costing well over $700. …
Tl* the contact owns a 1999 Oldsmobile Alero. The contact stated that the vehicle was driving roughly and there was a sudden increase in engine rpms. The contact had to apply force to the brake pedal on numerous occasions. The vehicle was taken to an independent mechanic who replaced the fuel pump, but the failure recurred. The vehicle was further inspected by the repair shop and the mechanic indicated that the timing chain was worn. The vehicle was not repaired. Also, the contact indicated that the console cover was not closing properly. The vehicle was included in NHTSA campaign number: 00V140000 (structure) and NHTSA campaign number:14V400000 (electrical system); however, the parts were not available. The manufacturer and the local dealer were not able to specify when the parts would become available. The manufacturer was notified of the failures several times. …
Locked up ignition switch cruise control fell apart gear shift shifter not secure and slides up the shift.. Both oxygen sensors failed all four windows electric motors, and racks have been replaced front end vibration when stopped or parked on incline dash board leather cover came loose and rolled up like a used rug original fuel filter have to be pried out of line and then pieces left had to be removed with needle nose pliers. Fuel gauge as never worked. Now its running about 4 miles and then quits, sets for 30 minutes and drive another 4 miles then quits. Code reader says engine running lean, (problem is 4 to 5 sensors including the injectors could be causing this, no way to tell with replacing them until it runs. The expense of this could be 1000 to 3000 dollars. Electric door locks failed , replace switch, only works part of the time.
Noticed my son's 1999 olds Alero was using excessive antifreeze, took to shop & had to have defective intake gasket replaced as antifreeze was being sucked into the engine. Repair shop reports that they are repairing same problem on 3 GM cars per week in this town of 25,000 people. Cost $ 650 to repair; GM should recall this vehicle & similar models and replace these defective gaskets, we were lucky that we did not ruin the engine on this car. We had to get the car repaired immediately as my son did not have any other vehicle to drive to work while the Alero was being repaired and really could not afford this expensive repair on this car. Repair shop advised that GM is not recalling this part or paying for the repairs even though they are aware of the problem and that it is the fault of a defective gasket and not the car owners fault.
Engine: 3.4l v6. The manifold gasket and water pump failed at approximately 40,000 miles. The dealer picked up the cost of the parts under their "goodwill" policy, but out of pocket cost to me was still over $800. The manifold gasket on my 2002 Buick rendezvous, VIN [redacted] also failed and had to be replaced at 18,000 miles. This was done under warranty at no cost to me. This was also the 3.4l v6 engine. It is obvious this is a problem GM has known about for quite some time and have not taken corrective action in a timely manner. An extension of the warranty on this engine is certainly called for. I have advised many friends to avoid purchasing a GM car with either the 3.1l or 3.4l engine.
Dt: 1999 Oldsmobile Alero. The contact stated the hub bearings on both sides of the front end went out. There was a noise coming from the front end, the contact took the vehicle to a garage. The mechanic told her of the problem, and said if she drove it much longer there would have been an accident. The head gaskets also blew out the engine. The vehicle was leaking antifreeze into the air system. The vehicle is currently at the garage being fixed for the head gaskets. Also, fuel pump went out while driving on the road. The vehicle was towed to the garage. Then, they replaced the fuel pump. The contact stated , in addition, there have been electrical problems. The computer system had to be reset a couple of times. This has happened within the past 12 months.
Engine complaints in other Alero years
Frequently asked questions
How common are engine problems on the 1999 Oldsmobile Alero?
NHTSA has 85 complaints about the engine & cooling of the 1999 Oldsmobile Alero, 18% of the model year's 462 complaints. The component named most often is cooling system (16 mentions).
Is there a recall for 1999 Oldsmobile Alero engine problems?
No. NHTSA lists no engine & cooling recall for the 1999 Oldsmobile Alero, though it has 3 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 1999 Oldsmobile Alero engine problems start?
Half of the complaints with a recorded mileage happened before about 63,000 miles, and 4% before 25,000 miles.
Is it dangerous?
Owners linked 0 crashes, 3 fires and 0 injuries to engine & cooling problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.