Bonneville will not start

Im sure these questions are on here often, but my situation is slighty different from the other thread, and your help would really be appreciated.

I have had my 2001 bonneville SLE for about 6 months now with no problems. I recently let my dad use my car and the next morning I went to drive it, it wouldnt start. Ive already ruled out the battery, everything else works and when I try to turn over the engine, the interior lights do not dim.

Whenever I turn the key there is no crank whatsoever, but I do hear a click or multiple clicks. Ive heard that it could be a multitude of things but given no clue on how to fix it or what it really is.

Thanks for your help.

There's a few gaskets on these motors that when they fail can let coolant into the cylinder. Since the liquid doesn't compress it can prevent the engine form turning over. We usually refer to this as the engine is hydrolocked.

1st thing we need to do is determine if the engine is hydrolocked or not. Easiest way to do this is by putting a ratchet on the bolt for the crankshaft pulley & see if the enine turns over in both directions. It should turn easily so don't force it if it's not moving easily. Let us know what you find. You can also turn the alternator if you don't have a socket big enough for the bolt on the crankshaft.

Based on the lites not dimming I would say the starter solenoid may be an issue or bad battery connections/grounds.

Play with the gear selector and maybe try to start it in neutral. The neutral safety switch may not be engaging. Is the security light lit or flashing when you try to start? That may be something else to check.

Another cause is the upper intake filling up with coolant and the series II 3800s are known for bad upper plenuims strating at the EGR port filling up the upper intake with coolant.The plugs have to be replaced since it also shorts out the plugs too