20 Most Recent 1994 Pontiac Grand Prix Questions & Answers

1. Loosen the four screws that hold down the top of the air filter box. 2. Loosen the clamp that attaches the air filter box to the intake hose. 3. Disconnect the air sensor connector from the top of the air filter box. Note: Secure the connector wire, it tends to drop down and more than once I have had to remove the air filter box to retrieve it. 4. Remove the top part of the air filter box. You may need to twist it to get it to release from the rubber air inlet Hose.
5. Remove the two bolts holding the bottom of the air filter box. 6. Remove the bottom part of the air filter box.
7. Disconnect the negative then the positive battery cables.
8. Remove the three bolts that hold the brace that goes over the Windshield washer tank. 9. Remove the brace.
10. Remove the Battery hold down clamp at the base of the battery.
11. Remove the two nuts that hold the fuse box to the fender well. 12. Remove the two fasteners from the front of the widshield washer tank. 13. Rotate the windshield washer tank away from the battery. You may need to move the tank and lift the fuse box to get the tank clear of the battery. 14 Remove the battery.
To Install reverse the steps.
Time: 5 to 10 Minutes

Hard to say over the internet but I will try to explain. If the noise is a distict KNOCK KNOCK and it sounds like it is coming from the bottom of the engine, then it most likely is a rod or main bearing. If it is a TAP TAP noise that sounds like it's coming from the top of the engine, then most likely a valve lifer is failing/failed.
the fact that it goes away when the car is warm, makes me lean towards a bad lifter. Normaly if a bearing is bad and knocking, the noise doesn't go away.

The KNOCK noise will be somewhat hollow sounding and the TAP TAP sound will be more solid. If the KNOCK KNOCK is solid, then a rod or main bearing has most likely failed to the point that a new/reman engine will be needed.

Run a compression test or...very carefully and on cold engine only: remove radiator cap, make sure coolant level is good, stand back and have someone hit the starter. If headgaskets are bad usually (not always) water will shoot out of the radiator. Sounds like this is your issue

Are the injectors opening?Use a NOID light and check for an injector electrical pulse.Or give it a shot of quick start,if it runs a bit and you do have fuel pressure the injectors may NOT be opening.(getting an electrical pulse)

Check the all wiring connections for corrosion. Also check and clean battery terminals. Check the ground to body and engine.

You need to get the trouble codes. The engine light is telling you that. There must be a stored code or two. See what they are and go from there. If no codes are present, have the fuel pressure checked for possible pump failure. If fuel pressure is correct (check specs, but probably about 45 psi) , then maybe an engine sensor is bad-maybe the MAF sensor. That's just a guess, though. Could be a bad computer, since it stalls at cruising, but could also be a problem in the ignition circuit-like the crank sensor or cam sensor.

I think it might be a temperature switch.

You may have water in your gas buy that little bottle that removes the water!? Good Luck Stevo

sounds like maf fault if a plastic accelerator the pedal sensor auto kick down solenoid

Head gasket ? What engine ? 3.1 l v-6 ? Coolant in the oil ?

Depending on how fast it reaches boiling temp, it could be a leaking head gasket or a blockage in the system. I am also assuming the cooling fan comes on at the correct temp. A blockage would do the same thing as a stuck thermostat, and a leaking head gasket would cause the system to have extra pressure.

If the problem is the fuel injectors, the computer won't ground the fuel injectors unless it sees an rpm signal? The voltage for fuel injector usually goes hot with the key on. The rpm signal comes from crank sensor and the ignition module may be involved. I haven't looked at your wiring diagrams, yet. Can you check for applicable trouble codes? If your fully obd1 compliant, you should be able to check some codes, yourself. Also, your antitheft where applicable could cause a problem?

Some things it could be but not specific to your vehicle. Do you smell antifreeze? Engine temps running hot? Has it run hot? No antifreeze in radiator, when cold take radiator cap off and look to see if it is full. add as needed in radiator and overflow container. Heater control valve not working properly or inop. Clogged heater core. Leaking heater core-heater core bypassed. Heater box door not operating properly or inop. Vacuum leaks or broken lines/cables. Intake manifold leaks Clogged radiator Could be many things, checks/tests need to be performed to determine the cause either by you or a certified repair shop.