Top 20 1990 Oldsmobile Ninety Eight Questions & Answers

Is the check engine light on, have it checked for codes and you might get a clue

You have to get a repair manual at PepBoys, Oreilly auto parts..

have you checked the connections? Make sure they are fully secured.

-4 Gallons ...? Sounds like too much. You mean 4 Qtr..? But any way. Don't expect the same amount that you pour in. because due to trap some in the filter, possibly the engine already burn some and may be some leak. Good Luck Mai

Could be. If the trans is stuck in park, you should be able to turn the front wheels if both are off the ground. Otherwise, if the brakes are not stuck on, and you can't turn either wheel with both off the ground, its the trans.

check your bulb.may be blown.

You cant check fuel pressure that way. You have to connect a fuel pressure guage to the fuel rail at the schrader valve. It should have 30-40psi when ignition is turned on. Injectors not functioning properly will cause a misfire Sounds like a fuel pump or fuel going out.

This car uses R12, it is no longer available, you must convert it to R134, this requires the compressor and reciever dryer be replaced and the system flushed out and the new PAG R134 refrigerant oil be added and new charging port kits installed. Is that car worth this effort?

Contact the local GM dealer in your area or a local auto slave yard for used piece

Sounds like the voltage regulator in the alternator is bad. Take the alternator off and have it tested (for free) at a parts store.

GM are usually in the trunk on same side as fuel fill door. Look for small hole on the sheet metal ribs on side of trunk.

You may need to test for a parasitic power drain, for example a horn switch that is stuck closed causing the horn relay switch to stay on continuously even if the wire was unplugged from the horn.

You will need multimeter to test for a parasitic power drain.

1. With the key off, disconnect the negative battery cable.
2. Connect the black multimeter test lead to the negative battery post, connect the red test lead to the negative battery cable.
3. With the meter set to the DC milli-amps scale note the current draw displayed. If it is over 20 mA, there is likely something drawing power that shouldn't be.
4. Leaving the meter connected have an assistant pull fuses one at a time (replacing them before pulling the next) until the meter reading drops. The circuit that this fuse powers is where the problem most likely is.

I dont think it has a fuel pump relay. Should be Ign. then fuse in fuse box then fuel pump in tank.

make sure connections are touching one another or touching ground.

Sounds like a bad turn signal switch.

It sounds like it could be a fuse isuue. I would first try to see if you can locate a fuse for the horn in your fuse box, ( fuse box should be inside, on the driver's side, under the dash, near the driver's door. When you remove the box cover, look on the inside of the cover, it may have fuse diagram to help you locate the fuse for the horn.

If it isn't a fuse related problem, you may need to run a new lead wire to the horn. The old wire could have be faulty from breakage, or corrosion.
That was good thinking using a jumper wire.
Best of luck!

pop the hood and count the spark plugs or cables or get the Vin number and call the dealer and have it decoded

I'm pretty sure it's #11 fuse - 20 amp-chime/cig ltr/radio/pwr ant. See if the cigarette lighter, chime , power antenna are not working also.

The connectors to the speedometers printed circuit are not making a good connection. Remove speedo to repair. Common problem.

maybe the heater core is plugged.
some people have been able to put compressed air into the heater hose going to the heater core dislodghing the blockage, but this has the potential of blowing the heater core apart if too much air is used.