So my 94 wagon does something a little odd when sitting in drive at a stop light. Periodically after it's warmed up, it will make what feels like thumping feelings from one to 3x in a row, stop and then if still waiting repeat several times over. However if I push the trans into neutral or park, this goes away. Additionally I can hear the transmission whining through the radio at times (I want to say this is a faulty ground, but not looked at it). I have performed the Tyler method and cleaned the filter but this still persists. If the thumping is occurring while driving I'm not able to feel it. I'm not sure what to do except replace this transmission, but otherbyhan the noise and feeling it still gets decent mileage

 

Can you set your parking brake, wheel chocks, leave the car in drive and take a video of this thumping?
I've had similar instances in other vehicles, but it is usually ignition related such as a slowly dying distributor pickup.
Usually car is idling smooth then a 'thum' and then clears up for a while but will come back periodically. That thar be a misfire.
Do the basics and make sure nothing is fubar.
If by 'you can hear the transmission' you can hear the gear change or a tone change whine when the trans upshifts, that is not the transmission you are hearing. What you are hearing is the different rpm change from a gear change. What also changes rpm/frequency when a gear change happens? Alternator. What is the most common sound or backfeed noise you can hear through the speakers with a faulty ground or bad capacitor? The alternator. Look for bad/loose grounds, if a factory radio check that the factory cap/choke is still intact if applicable. If an aftermarket head unit, check for correct wiring.

Dunno what your mileage is so FWIW.
'95 EX Coupe, F22B1/MPJA
Normal driving(like a dickhole) 70% freeway, ~29MPG
Stuck in stop-n-go traffic with max speed of 40MPH, ~25MPG
Drive like a geezer(singing 'the old gray mare') and pissing people off on the Lincoln Highway, ~34MPG

 

I haven't swapped transmissions yet, but from this video, I think one tell it's happening when the motor is shaking. Please ignore the clattering, I probably need to do a valve adjust or something. Sorry for the delay in posts

 

Also no CEL or Blinking D4 still.

 

are you sure the thumping feelings aren't from a bad engine mount? if you could mount a camera on the hood or on a tripod on the ground, put in it drive while you hold the brake pedal down and then watch the video to see if the engine itself is shaking, that would at least rule that out. it can't be an out of balanced torque converter, it can't be broken tooth on the gears, those wouldn't thump and then stop. you probably have a broken front, or possible back engine mount, rubber probably separated off the mount and the whole engine is bucking

 

Did you do a cylinder drop test?
Compression test?
If you haven't adjusted the valves in a while, exhaust could be on the tight side leading to weak compression.
The vibration is pretty constant and cyclical.
Pull plugs to see if any one of them is ever so slightly richer looking than the rest.

Don't rely on the ECM to tell you anything,
These ECMs are durable and reliable but they, like most speed density systems, are **** at self diagnostics unless there is something horribly wrong. Especially the pre OBDII systems.
Even an obvious misfire will not set a proper code.

 

I will try the tests, and the car probably needs a rear mount, as it vibrates noticibly while waiting at lights. I replaced the front mount some time before the problem manifested. The video was taken with the car in drive and a bar holding down the brake so I could film it. With the car in park the engine idles perfectly, none of the heavy vibration/"thumping" which is what lead me to think it was a trans problem, but perhaps it's just the load on the engine egging on the problem. Also I should note the car while in drive idles around 750 or so at a light with no rpm swings when the thumping occurs

 

Yeop.
No load conditions usually don't show much unless there is a gross problem.

Front mount on 94-97s(98-02s?) is just a simple 'stopper' or limiter. It doesn't hold the weight of the engine, just aids in limiting its movement.
If that front mount is torn or shredded, the rear mount is most likely also dead. With an AT car, verify the hydro mount and its controls are functioning as well.

 

So I'm coming back to this. I finally just swapped the distributor, cap, and wires off my other accord that was running great up until the timing belt bit the dust. This seems to have cured the problem but I won't know until I take the 100 mi round trip tommorow. But this lays creed to a faulty/failing ignition issue of some sort. I had swapped coils with my spare but no change about a week ago.

 

So yes, it seems the problem was the distributor. I will need to test the other components to see what was failing, but that's going to be harder to do since the symptoms didn't appear until the engine had been running for a while (heat soak?)

 

Yeop.
The fun of diagnostics. Get her good and hot, when **** starts acting up start looking.
If the problems are consistent with simply going from Open to Closed loop, then that will narrow down what sensors/harness needs to be checked.