One mechanic told me I needed a timing chain but better off buying a new engine but this seems odd because I didn't have knocking or smoke the car just stopped so what are the chances he could be right

could be a big end or main bearing but there are a few simple checks that can be done first
1--have the oil pressure checked using a mechanical gauge
if there is a bad bearing there will be low pressure at idle
2 --check the exhaust for smoke under load
if there is a bad bearing , the escaping oil will overload the oil ring and produce smoke
( if smoke comes after idling at lights and on taking off that is valve stem seals)
3--- run the fault codes and check for knock sensor problems
the noise could be detonation under load from lean fuel mixture or incorrect timing
4---check the ignition timing
5-- run the engine when it is knocking and remove a plug wire and see if the knocking stops
bearings will stop knocking if there is no combustion to place load on the crankshaft
That will also indicate which big end you have to check if you have to pull the sump
Too far advanced will cause the pistons to slap the cylinder walls hard for too far advanced ignition
you statement that the noise goes after 40 indicates that it is not a bearing as the high the rpm the louder the noise
taking the foot off the pedal indicates detonation
lastly if all the checks prove good , you could always have the sump removed and check each big end and main individually for damage
sometimes a failing cam chain if fitted ( no motor identified) will knock as the chain hits the timing cover

The smoke under hood means that u need replace gasket between exhaust pipe and engine but smoke and knocking is not very good, it looks like your engine pistons has cracks and u r loosing oil by smoke time to time, i'd buy used engine from crashed car with less miles on it

Did you check your oil level? You may have too much oil. Does the car still run? Were there any odd noises, like pings or knocks? Flashing lights usually mean time to see a mechanic.

Hi Janay, It would not take a good mechanic more than lifting the hood and listening to the engine to determine that the engine had knocked. By all means have someone else have a listen and a look and wait to hear the diagnosis they give. It's always a good idea to have a vehicle serviced on a regular basis. If you needed to add oil, to have the sound of the engine change, It sounds like you didn't bother? If the engine knocks more when you apply gas it seems to me that the connecting rod bearings and the small end bearing have both been damaged by the lack of lubricant (Engine oil). If you like the vehicle replace the engine, if not replace the vehicle. Regards John

Have a mechanic listen to it to see if it's a loose piston rod knocking (rebuild time!). Is it a high mileage engine?
Those are very good engines, but have a known problem with the timing chain guides and tensioner wearing, making noise, and need replacing. I think there are aftermarket kits sold to correct the problem.
Good luck.

Did changing the oil cause your light to go on? You didn't say if the noise started all at once or if it has gotten louder over time.

Typically a knock not related to predetonation ("pinging") will typically come from the connection at the crankshaft to the piston connecting rod. A slapping sound may occur if the connecting rod pin is sloppy or part of a piston skirt is damaged. I had a 98 Durango but can't remember if you have hydraulic lifters. A bad lifter can also emit a knock. If you have more of a clatter check the rocker arms. It's also possible a pushrod is bent. Use a mechanics stethescope or metal rod and try to isolate the noise source. The precise location of the knocking will improve you odds of solving the problem.

Big job to you, most likely

You need to buy a manual for
doing timing chains,can't tell you how,
too complicated

SOUND LIKE LEAKING HEAD GASKET.ANTIFREEZE IS BURNING WITH FUEL CAUSE SEVERE ENGINE MISFIRE THATS WHY ENGINE SHAKING BAD ITS MISFIRING.TIME YOU NEED A NEW ENGINE WHEN ITS SMOKES HEAVY BLUE SMOKE USE A QUART OF OIL ONCE OR TWICE A WEEK.

these 3.3l engines are equipped with timing chains. if vehicle has prolonged down time, typically more than 4 hours, vehicle makes a chatter until the timing chain tensioners put tension on the chain. you will need them replaced.

I doubt it is the timing chain. More than likely it is the valves themselves, the seats wear out, and the lifters wear, so eventually the lifters don't pump up as full as they should, so it causes a gap between it and the valve, so it slaps the valve, also the seats wear, so the valve is kinda loose, so that causes a gap between it and the rocker shaft, so you get another slap. If the chain wore out enough to be hitting the block or front cover, you would be having timing issues because it would have to be pretty loose. You may also have a failing oil pump, so it is not suppling the right pressure, which is why you hear it at idle, because under load the pressure goes up and as I said it pumps up the lifter. This guy is a joke if he told you just to drive it till it blows, which would cause significant damage, Then you have to buy a what? use motor for $600 that is no better off than what you got? Then pay someone like this idiot $500 to install it? Right now you could probably rebuild the engine for about $600, and have a brand new fresh motor for your truck. The chain is not too difficult, you can do it in the car, but would be much easier out of it. The head doesn't have to be removed to do it, but you do have to take off the timing cover, which can be a pain, and possibly the water pump, all the engine pulleys, alternator, etc. So thats why I suggested pulling the motor. And, when it is pulled, it would be a great time to freshin it up with new pistons, rings, bearings, have the block done and rebuild the head.