98 Grand Prix GTP wont start...

I started the car up after it has been sitting in the driveway for a month and it started right up, i let it run for about 20 minutes before taking off and going to the gas station, so of course I turn the car off and fill it up but when i go to turn it back on, nothing. All the interior lights worked and me and my dad had just replaced the battery a couple of weeks ago, we tryed to jump it any way and it didnt work of course, the car makes no noise when we turn the key exept for what i think is the fuel pump. The starter and the crank of course dont make any noise as they are not cranking. Now i guess Ill give a little background on the car, my sister had been using it before we got it back and for some reason now the Headlights stay on at all times no matter where the switch is toggled. There is also a little black box down by the pedals that has alot of wires running into it that me and my dad hadnt noticed before, i have no idea what it is or if it is what is causing the lights to stay on. My dad doesnt think its the starter because we just started it up that morning fine. Im really confused and our car is stuck at a gas station right know, any help will be appreciated and if there is anything more i can tell you please ask. And sorry for my writing, i am just a bit mad right know

The lower intake gaskets on these engines can fail & flood the cylinders with coolant. Since the coolant won't compress this can prevent the engine from turning over. We refer to this as a hydrolocked engine. Don't keep trying to start it until yor sure it's not hydrolocked. Put a socket on the crankshaft & make sure it rotates in both directions. Don't try to force it. If it only turns in one direction then it's probably hydrolocked & you'll have to remove the spark plugs to get the water out & then replace the gaskets.

Does the ignition key have a resistor pellet built into it? If so sit in the car with the doors closed & turn the key to run. The security light should come on for a few seconds & then go out. If it stays on then you'll have to replace the ignition switch or do a security bypass.

You can also try moving the shifter around & see if that helps. It should only start in park & neutral but the switch can go out of adjustment.

Can you get a picture of the box & wires, someone will know what it is.

The lower intake gaskets on these engines can fail & flood the cylinders with coolant. Since the coolant won't compress this can prevent the engine from turning over. We refer to this as a hydrolocked engine. Don't keep trying to start it until yor sure it's not hydrolocked. Put a socket on the crankshaft & make sure it rotates in both directions. Don't try to force it. If it only turns in one direction then it's probably hydrolocked & you'll have to remove the spark plugs to get the water out & then replace the gaskets.

Very uncommon and I've never heard of the LIM gaskets catastropically failing to cause that issue so I disagree. Really not an issue in that respect on the supercharged L67 version of the SII 3800 engine. The hydrolock condition is more applicable to he L36 NA SII 3800 with the plastic UIM plenum, especially 97-98 models with the EGR stovepipe issue.


Does the ignition key have a resistor pellet built into it? If so sit in the car with the doors closed & turn the key to run. The security light should come on for a few seconds & then go out. If it stays on then you'll have to replace the ignition switch or do a security bypass.

The 97-98 Grand Prixs do not have the old Passkey I/II resistor pellet on the ignition key or a Passlock system. Most use a hybrid content based VATS and factory alarm system. For 1999 and up GM added the Passkey 3 VATS/Immobilizer system.

. The starter and the crank of course dont make any noise as they are not cranking. Now i guess Ill give a little background on the car, my sister had been using it before we got it back and for some reason now the Headlights stay on at all times no matter where the switch is toggled. There is also a little black box down by the pedals that has alot of wires running into it that me and my dad hadnt noticed before, i have no idea what it is or if it is what is causing the lights to stay on.

Check for 12 volts at the starter solenoid "S" connection at the starter with ignition to ON/START. Should be a purple wire. Also, check all the IGN series of fuses listed at the main engine compartment fuse box.

The boxes found left driver side of dash are the body control module and daytime running lights module.

Very uncommon and I've never heard of the LIM gaskets catastropically failing to cause that issue so I disagree. Really not an issue in that respect on the supercharged L67 version of the SII 3800 engine. The hydrolock condition is more applicable to he L36 NA SII 3800 with the plastic UIM plenum, especially 97-98 models with the EGR stovepipe issue.

I realize the LIM gasket failure usually 'just' spills coolant into the crankcase but believe it's also possible for it to get into the cylinders. A head gasket failure can do the same thing. It only takes a minute to put a wrench on the crank or alt bolt & make sure the crank turns. It sure beats breaking the nose off a $200 starter or possible bending a rod & destroying an engine.

I realize the LIM gasket failure usually 'just' spills coolant into the crankcase but believe it's also possible for it to get into the cylinders. A head gasket failure can do the same thing. It only takes a minute to put a wrench on the crank or alt bolt & make sure the crank turns. It sure beats breaking the nose off a $200 starter or possible bending a rod & destroying an engine.

Unless he cracked a head, LIM, or Supercharger, (very unlikely) the only real way for coolant to get into the cylinder chambers is through the t-body coolant passages that flow between the Supercharger and LIM. Its possible to leak here, but very unlikely because it is double gasketed sort to speak. Each passage has a rubber o-ring and then the supercharger gasket itself in theory should block any coolant that gets past the o-ring.

Putting a wrench on the crank is a good suggestion, however if he cannot turn it, I would lean more towards an oiling problem which caused the crank to sieze up rather than a hydrolocked condition.

My interpretation of the symptoms was that the starter was not doing anything. I would simply try turning the key to start and then moving the shifter around a little bit to see if the safety switch is defective. Try starting it in neutral. Checking for voltage at the starter like BNaylor said is even better. Sometimes repeatedly going start/nostart/start/nostart/start/nostart will work.