Fox M 1112 knocking sound from headstock area - machine new gears or motor not involved thx

it could be the torque converter. something is failing around that area.

SOUND'S LIKE YOU COULD HAVE A BAD ROD OR CRANK OR LIFTER.TRY THIS CHECK YOUR WATER AND OIL NOW START THE ENGINE IF IT IS A FAST KNOCKING HOLD YOUR FOOT ON THE BRAKE AND PUT THE CARE IN GEAR IF IT QUEITS YOU HAVE BAD ROD SERIOUS MOTOR REPAIR INTERNAL.DO THE SAME THING AGAIN AND IF IT IS MORE A THUMPING NOISE AND A SLOW DEEP KNOCK THEN WITH THE ENGINE IDLEING PUT IT IN GEAR HOLD THE BRAKE GIVE IT A LITTLE GAS AND IF THE MOTOR KNOCK'S GET'S QUEIT IT'S POSSIBLY THE CRANKSHAFT ANOTHER INTERNAL PROBLEM MOTOR OVERHAUL IF IT'S A FAST RATTLING IT'S PROBABLY A LIFTER STUCK OR BLEED DOWN DIRTY OIL OR A WEAK OIL PUMP ALL ARE BAD NEWS SORRY.GOOD LUCK

this could either be caused by the solenoid valve or the bendix drive.

solenoid valve is attached to the starter, bendix drive is a set of gears being turned by the started while cranking

I think I would pull the timing covers back off and see if one of the pulleys etc. is loose. Did you put the proper tension on the timing belt? It is also easy to put that belt on one tooth off, the motor will still run and can produce the knocking noise, take care and good luck. ps I assume the oil level is good in the motor.

usually a knocking sound indicates that there is either a rod blown, if it is a ticking sound it could be your heads are not tight on enough.

probaly the temp door actuator motor plastic gears break or theres somthing in the way of the door anything fall down the deforster vent lately.

Sounds like a ac door actuator motor is broken,

the noise is characteristic of this 4.1 liter ht4100 engine. the problem lies in the #1 main bearing clearance. this noise is very common on this engine and will clear up when replacing #1 main bearings but might return after you put some miles on it. i fixed a lot of these as a cadillac tech for many years. good luck!!

if it only knocks or clunks puting in gear or gettingonit I would check motor & trans mount both upper dog bone & cross bars to core support

The knocking or ticking is going to determine if it is in the top end, lifters, push-rod or rocker arm issue or the bottom end that would include pistons or bearings.
If it is a ticking noise, it will more than likely be a valve train issue.
If a knocking noise, piston or crankshaft related problem.

Attached is a web site that you can listen to a piston slap which is a known issue for your 4.3.
Listen to the noise and see if it sounds similar to your problem. A piston slap will generally sound as though it is coming from the central area of the engine.
Listen to the recording and let me know.
Regards,