Broken timing belt???

[KingSizer]

i noticed a 'knocking' this morning on my way to the office. when i left the office i checked the oil which was fine. i put a bottle of lucas valve cleaner/gas conditioner into gas tank. no change to the knocking. knocking increases/decreases with rpm's. seems to not be as loud when i'm accelerating but gets louder as soon as i take foot off gas pedal and at idle. drove about 15 miles, i heard a quick squeal that i thought was serpentine belt. another 500 feet and another quick squeal then the engine died. i coasted into a parking lot, put car in park and turned key but engine wouldn't even turn over.
please help with ideas. my research tonight makes me think timing belt. its a 2006 sxt, 3.5 v6, 123000miles. was running pretty good up to this point 18-20 mpg. only problem i've noticed lately is engine would heat up all the way if i was sitting in traffic or at a drive thru for too long. it didn't heat up all the time, just occassionally. i've been thinking loose fan wiring connection or a stuck thermostat. but maybe water pumps been acting up?
i really appreciate any help and ideas...

[Fireman2118]

In your Manual, the service interval for changing the timing belt is 105,000 miles. Unless you've recently changed it, you may have broken a belt. Definitely going to require an internal investigation.

[KingSizer]

i never changed it. i got the car with 70000 on it and i'm pretty sure it wasn't changed before i got it. Is there any easy way to find out for sure it the belts gone?

[Fireman2118]

When you turn the key, does the motor turn over? Do you hear anything?

[D-Rock]

I'm not familiar with that motor at all. But usually you can take off the valve cover and rotate the engine. If the valves don't move your timing belt/chain is usually broken. But, when they do break, it usually involves more then just replacing the belt, there is usually some damage to the engine too.

[KingSizer]

damage to the engine too? thanks D-Rock.
and no, nothing happens when i turn the key.

[D-Rock]

Yup, you have pistons still moving and valves that are not. There gonna collide......

Do you hear the starter trying to engage or is it just nothing......dead silence?

[Fireman2118]

damage to the engine too? thanks D-Rock.
and no, nothing happens when i turn the key.

Yes, when the timing belt breaks, the valves stop moving and those that stop in the open position can be struck by the piston(s). Nothing you can do but have it towed to a shop or have a mechanic come out and diagnose it.
I'm not saying that this is what happened. It's a possibility though.

[KingSizer]

dead silence

[Fireman2118]

Do the dash lights come on? The radio, headlights, etc?

[D-Rock]

That doesn't sound like a timing belt. The starter should still be trying to engage. is there any power to your car at all? (headlights, horn, interior lights, dash, etc)?

[KingSizer]

would the 'knocking/slapping/clapping' noise and the squeals be a good indication its the belt also? has anyone heard the noises i'm referring to before?
and thanks Fireman and D-rock for your thoughts. fortunately i was able to coast into a parking lot when it stalled. and i've got the names of a few mechanics i need to call tomorrow. i'd just like to have a good idea what it is and how much a fix like this might be going to cost me...

[KingSizer]

all the electrical work. radio, bluetooth, headlights etc

[D-Rock]

Hard to say, might be something like ac compressor bearings locking up. but that wouldn't explain your starter not working so its probably something electrical. can't think of anything off hand that would make those noises that would be electrical unless your alternator was locking up/dying. good luck, hope its nothing too bad.

[05maggyrt]

motor could be siezed < worst case senario