2013 dodge dart no compression cylinder 3

If you have access to a boroscope, you could remove the #3 spark plug and look inside the cylinder at TDC position to see if you can see any damage to valves, or if one is open, or if there is a hole in a piston. You could also remove the valve cover and look for anything unusual with the valvetrain at cyl 3.

I actually ordered a borescope yesterday.

I was told 90k on the engine and car has 185k on the odometer. I would think if the belt let loose, all the valves would crash, not just cylinder 3. Car runs, just number 3 is dead. Plugs look to have been changed and some coils too. I don’t know anything about the multi air brick valve setup, but I read each valve is controlled separately.

If you apply air pressure to the #3 spark plug hole at #3 TDC, where does the air escape from? Throttle body? Tailpipe? Oil filler cap hole?

Any valvetrain fault codes or just P0303?

My timing belt went at 67k

ImperialCrown said:

If you apply air pressure to the #3 spark plug hole at #3 TDC, where does the air escape from? Throttle body? Tailpipe? Oil filler cap hole?

Any valvetrain fault codes or just P0303?

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I haven’t tried a leak down test yet, just compression. No other pcm codes, just the P0303. I had a bcm code, B2204-55 ecu mismatch not configured and a hvac U0422-00.

Well piston looks fine via borescope. I can’t see the valves, can’t maneuver the camera enough. I’m going to pull the valve cover when I have a free spot in my garage next week.

Pulled valve cover, everything looks ok. Timing belt looks good. Leak down test has air going in the exhaust on cylinder 3. Is there anything else stupid to check before I pull the head?

Since you don't see any chips or cracks in the piston, I'd pretty much guess that you have a stuck or burnt valve. Time to pull the head and check it out.