S80 Ticking Under Gas Pedal Now Won't Start

[catburke]

My 2000 S80 quit while driving the other night. About two minutes before it quit, I started hearing (feeling) a ticking noise under the gas pedal every time I pressed the accelerator. At first it would stop ticking when I took my foot off the gas, then gradually became constant. I was on interstate and heading for nearest exit. Gradually acceleration also became lessened, and when I got to long off ramp, about 1.5 minutes, was down from 55 to about 30 with no braking. As I reached the end of ramp, engine shut down, ticking noise went away, and car stopped. I put in park and popped the hood. Smoke was coming from behind the engine against the firewall, couldn't really tell where from. Nothing dripping out the bottom, except maybe water, but the road was wet from a storm earlier. Definitely no oil or fluid on the road, though, not even water with antifreeze in it. But it was smoking, not steaming.

The car was then stuck in park. I couldn't get it to move at all. This car doesn't have override switch. Called a tow truck and they got the car home. When I got up the next morning, got in the car, and it came out of park normally, maybe from shaking it off the flat bed? Anyway, the engine cranks, but it won't start. There is fuel. I just replaced the spark plugs now. They were looking pretty ugly, but only one smelled like it might be burnt. The rest smelled like gas.

Is there a sensor or relay or something right under the gas pedal or in that area? The ticking sounded kind of like when the battery gets too low after cranking too long.

A side note: car could have been overheating, I have a continuous small leak at lower radiator hose, I checked the coolant a week ago, usually it doesn't go so fast, but this morning I had to put about 20 oz of water/antifreeze in, it was completely not showing in the reservoir. Usually it only takes about 2 oz. My dashboard has been dead for about a month, I use an app on my phone for miles used and mph. My brother who is versed in this type of repair took the dash apart but the solder etc on the inside looked pristine. The check engine light has been on forever, only thing that lights on the now dead dashboard.
The oil still looks dark, not peanut butter color.

I just need to know where to start to figure out how to get the engine to catch. Everything seems to be working, but it won't catch.

Thanks, Cat

[chrism]

Ticking sound when under throttle load + possibly being overheated + smoke coming from the behind the engine = sounds like a blown head gasket. An exhaust gasket leak can make a ticking noise when stepping down on the throttle, but that usually won't keep it from starting.

You could check over the exhaust and turbo connections to see if there is anything obvious, but I think you need to pull out the spark plugs and run a compression check on all cylinders.

[boosted5cyl]

Yep exhaust leak can sound like tapping. Skip compression check and go straight for a leak down though.