Drove from Florida to Texas recently, got 36 mpg running the a/c and cruise at 78 mph.
Pulled into a gas station 1/2 mile from home, shut it off. Came out 3 minutes later, restarted the car and it was running REALLY rough. Nursed it home, put the OBD scanner on it, no codes. Tried changing the coils, plugs and cam sensor, no change. Revved it up, thinking it was loaded up then shut it down.
Next day, tried to start it, would only crank. No popping, banging or any attempt at starting.
Pulled the front valve cover for giggles and found a ton of baked on sludge.
I have had it for about 9 months, changed the oil regularly and did a Sea Foam treatment on it when I bought it.
My thought is this: one of the timing chain tensioner got stuck from the sludge, which allowed enough slack to advance the timing, thus the 36 mpg at 80 mpg. In the process, the tensioner stayed back far enough, that when I shut it down, the chain jumped, causing the no start.
The car had 128,000 on it and ran like a scalded dog up to this point.
Any thoughts or suggestions beyond the obvious compression check??
Should I be looking for another engine? or cut my losses where I am? I know it's an interference engine, but I can't help but wonder if it's damaged

 

Maf sensor, knock sensor, injectors are a few guesses

 

Get a compression guage. Screw into each spark plug hole. Remove fuel pump fuse. Write down the reading on each cylinder. Compare to what they should be.

If the readings are low, you have a problem.

 

[QUOTE=JvG;9148747]Get a compression guage. Screw into each spark plug hole. Remove fuel pump fuse. Write down the reading on each cylinder. Compare to what they should be.

If the readings are low, you have a problem.



Sorry, I read that you have already considered a compression test.

If you have access to compressor, you could bring a suspected bad cylinder to tdc with all valves closed. If any valves are bent, you should hear air escape from either the intake or the tailpipe.

 

[QUOTE=JvG;9148748]Yeah, that would work also. Might also tell me if the valves are actually open when they should be closed, verifying the cams have moved. Without tearing a head off there isn't really any way to be sure

 

Any other ideas? Am I on the right track?

 

[QUOTE=Noah Heflin;9148808]If the chain has jumped, the valves might have been bent by hitting the pistons. A leak down test with a compressor whIle the cylinders are at tdc would confirm this. A compression test would also offer clues.

 

Confirm, spark, fuel and compression. Then report back.