03 navigator, slight tick from drivers side and misfire.
 

Hey guys,
a week ago i picked up an 03 navigator with the 32v engine. I got it for a really good deal from a friend. When i bought it, it was misfiring and running very poorly so i did the basic tune up on it. I did all the plugs, boots, and changed out 4 of the ignition coils on the drivers side because 1 was bad and i figured its time due to.its age. Anyway, im having a weird issue thats kind of left me scratching my head. Ive owned and worked on modular engines since i was 18 years old, but this is my first dohc one.

Anyway
when i first start up the truck, the engine idles perfectly and quietly. After i drive for about 5 minutes, when i come to a stop, i hear a faint ticking noise that sounds like its coming from the drivers side, and the truck will misfire. Not like a dead hole, but its enough to slightly shake the truck. It sounds like its coming from low on the engine in the crankshaft/ side of the block area. It isnt like a rod knock or a spub bearing sound. I tried to pull codes, but its not reporting any, and even after driving it a bit there are no codes present. Under load, it feels normal, and doesnt seem down on power. If i put it in neutral and rev it a bit, when the revs come back down, itll dip really low down to about 400, and then slowly recover. I will take a video of it later.

any ideas off the top of your head as to what it could be? I know its hard to diagnose without hearing it.

Thanks,
Andy

Alright, now the misfire is pretty much constant. Still no codes present. Im going to and unplug 1 coil at a time to narrow it down. Are injector failures common on the 32v? I have a huge bag of the orange 19 pounders but they are the wide body style and the ones on there look like they are the newer skinnier style and they are white.

The ticking could be the exhaust manifold. The hold down studs are known for rusting and breaking off.

Also this could be a lash adj not pumping up. I just had my new engine run rough for a bit but smoothed out after running. I believe it had air in at least one lash adjuster.

Here ya go,
i took a video of the sound. Im really.hoping that i dont have to yank this motor and go thru it. Strange thing is the noise and misfire are.only detectable at idle.once its warm.

https://youtu.be/gaONcprlwgs

lemme know what ya think.

Sure sounds like a rod bearing spun.
when these engines loose a rod bearing the piston contacts the head. I believe that is your issue sadly.

I was hoping its not something like that, but from all the modulars i have worked on that have had issues, the sound is all too famaliar, but usually its super loud and sounds angry hahahah. Shes got over 200k on her and its gonna be my family vehicle when we dont want to take the f350 around town so i need to make dang sure its reliable. When the driveway is clear i think i will yank the motor, and completely go through it. New valves, new guides, new gaskets, etc. This will be my first 32v build so im kinda looking foreward to it but not looking foreward to spending the money lol.

dumb question but...
whats the average life span on the lash adjusters. On one of my offroad projects i reused em during a backyard rebuild even though the engine had 230k on it and it ran great, but i have heard the horror stories. When i worked at the dealer they would send us complete heads, parts, etc so we didnt usually didnt get into individual component replacement, but when your working on your own stuff its different.

any other parts besides the wear items that i should replace while im in there. Im planning on reusing the pistons, cams, crank, rods etc as long as they are good.

thanks

Sounds like a rod bearing to me as well.