'98 Chevy Malibu develops 4 problems overnight

[flyiniowan]

I'll try to be as detailed as possible with this. I'm completely perplexed as to what could have happened to cause this problem. I have a '98 Chevrolet Malibu, 4 cylinder model, 2.4L engine, with antilock brakes (ABS) and an automatic transmission. The car is in Iowa, where it is currently very cold, snowy, and icy on the ground - I don't know if this makes a difference, but it might.

Anyway, I took the car for a drive this morning - 10 minutes to and from the grocery store, without trouble. I took it out again about 2 hours after that, this time to go to the bank, and when I got back in started it, and began driving again, the blower motor was making more noise than usual - it sounded like it was turning faster than normal, and indeed, the air coming out of the vents was traveling considerably faster than it normally did at that setting. I thought nothing of it.

Then I noticed when I went to stop that the brake pedal was stiffer and higher up than I remembered. Pressing down on the brake used to be like stepping on a squishy piece of bread. Now it was like trying to crush rocks. Again, I thought nothing of it and continued on (this is 30 seconds after I've been back in the car). Then the maintenance warning bell made an alarm and the ABS light turned on on the dashboard. This was immediately followed by the Airbag Warning Light turning on and remaining on. I parked the car, shut it off, turned it back on. The airbag light again stayed on, but this time the ABS light was off. I drove another 100 ft, the ABS light turns back on.

Additionally, as I was driving along, the transmission shifted VERY hard between first and second, as well as between second and third. I also noticed that the dashboard console lights were MUCH brighter than usual. I'm thinking something is wrong with the electrical system in the car for so many things to start happening all at once.

A few things to note: this vehicle got stuck in the snow two nights ago. I had to rock it back and forth about 5 times to get it unstuck. I know that's terrible for the car, but it was an emergency and I had to get my car going. There were no problems with the car during the 6 or 7 times I drove it after getting it out of the snow, including one time on the highway at 70+ MPH.

[DanD]

Have the charging system and battery tested, with the heater blower motor blowing harder then normal the alternator maybe over charging, causing battery voltage to be forced higher then what the working systems are designed to run at.
Computers react by receiving voltage signals form different input sensors, if the source voltage (battery) is either to high or to low the computers get confused to the point they shut themselves off and turn on their tell tail lights.
If this is the situation, it should be checked and repaired as soon as possible or damage to electronic units and the battery will or could happen.
Dan.

[flyiniowan]

Thank you for your advice and help. I checked the battery voltage with the engine off; the voltmeter read 12.4V. With the engine on, it was at 16.8V, far above the "14.5V" rating I found listed in the Haynes Repair Manual for this make and model. I took it over to the local NTB; they checked the alternator and it turned out that was the problem. They also reset the engine diagnostic codes for the airbag system and ABS brake system too so the lights aren't a problem anymore.

It turns out the voltage regulator (built into the alternator) was bad and the alternator was putting out a higher voltage than it should have. Since the ABS system and the air bag system are both computer controlled and sensitive to high and low voltages, the warning lights for those can be explained by the computers not functioning properly due to the over-voltage from the alternator. I don't know much about transmissions, but since this is a '98, I wouldn't doubt that is electronically controlled too... explaining the harder shifting due to the high voltage.

I drove the car from Iowa to Illinois with it in this condition (a bad idea, I know, but I had to get home from college). I had no problems while I was driving (I drove the 3+ hours straight through to avoid having to shift gears and beating up the transmission too much since it was shifting hard). When I got home, the battery was leaking, though, and smelled very bad.... probably from overcharging. NTB says the battery is still fine and doesn't need replacement. I have a feeling the only reason they're saying this is since the battery is under warranty through them and is only 6 months old. We'll see how well it works for the rest of the winter now that some of the acid has leaked out of it. Hopefully it will fail before the 18-month free replacement warranty expires.

Thank you all for your help!

[way2old]

Good call Dan. Glad you on the site.
;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D

[DanD]

I’m glad that Venturi’s could help, Please feel free to come back anytime and tell your friends.
Dan.