Jerky, Sloppy Shifting or?

[mbrando1994]

I'm having an issue where when pressing on the accelerator I get a bump that can be felt through the entire vehicle, it's been doing it for a while and can't remember when it started. It also does the same whenever letting off the gas, seems like the whole car jumps almost, it's not severe, but enough of a feeling to cause me to worry something's up. It shifts manually into all three gears, and no noticeable problems when shifting up or down in drive. It's an automatic, AWD 4.0 on a 2003 Explorer XLT. What could be causing this?

Thanks

 

[07gtman]

On the shifting part of these issues.Best case is a clogged transmission oil filter.The bump on the start and deceleration,hard to say,Could be u-joints propeller joint or rear end. somewhere to start, How many miles on it.

 

[mbrando1994]

By transmission oil filter you mean the flat looking one that sits above its pan? It was replaced about a year and a half ago and did not resolve the issue. I've been told that the differentials may need work. There is around 190k on it and about 140-150k on the engine. Transmission fluid change and filter a year and a half ago and all but one wheel bearing replaced. Where is the propeller joint?

 

[07gtman]

That is rear part of the front drive shaft.
Explorer Propeller Joint

 

[07gtman]

So when you take off in drive .What gear does it start in?

 

[edcantu9]

it could just be a misfire.

 

[07gtman]

Do you have check engine light on? even if you don't you could go to auto zone, or any parts store and see if there are any codes.they will do it for free

 

[07gtman]

it could just be a misfire.

very good point when was the last time you changed the plugs and wires.

 

[edcantu9]

Get a scanner that shows mode 6 data. It will tell you if a certain cylinder is misfiring. don't do anything until you know what is the actual problem. that is 2/3 the battle. the blue driver obd2 scanner on amazon is great for this and cheapest one i know that shows mode 6 data.

 

[mbrando1994]

So when you take off in drive .What gear does it start in?

I believe first? RPMS usually read around 750-1000 at low speeds and idle, when accelerating they usually sit around 2000 or above. It seems more difficult lately to get it to second or third, not sure which one because I always remember being able to easily accelerate to 50mph at around 1500 rpm, now I need to push it up to 2000 to get the same result.

 

[mbrando1994]

very good point when was the last time you changed the plugs and wires.

Coil pack, wires, battery, and starter have all been replaced with quality parts. I am not sure about the plugs and that is even on my spring to do list. I have a bluedriver and it is throwing no misfire codes, I have a code for a possible thermostat stuck open, one for it not being able to bleed up fuel tank vacuum, which it's saying is most likely due to a canister vent solenoid, and then code P0430, catalyst system efficiency below threshold bank 2.

I have not tried mode 6 yet, how does that work and what should i be looking for?

 

[mbrando1994]

Get a scanner that shows mode 6 data. It will tell you if a certain cylinder is misfiring. don't do anything until you know what is the actual problem. that is 2/3 the battle. the blue driver obd2 scanner on amazon is great for this and cheapest one i know that shows mode 6 data.

I have a blue driver, what exactly do I look for in mode 6? It's not throwing any misfire codes

 

[mbrando1994]

I ran Mode 6 while in the car, everything passed except three items, I will list their results in full here:

Description not available
Status: Complete and Fail
TID:10 ID:21 Min:- Val:0x37 Max:0x33

Description not available
⚠ Status: Test not complete
TID:55 ID:00 Min:- Val:- Max:-

• Description not available
Status: Complete and Fail
TID:56 ID:00 Min:- Val:0xFFFF Max:0xBB8

I do not understand how to read any of this or diagnose anything based on these results. A lot of them have descriptions but the three I need do not, please help!

Thanks!

 

[07gtman]

- TID $53 CID $01 MEASURED 420 MINIMUM 0 MAXIMUM 20,992 "PASSED" ... TID $53 (TID $51 ON EARLY OBD2 FORDS): Cylinder-specific misfire rates in percent and the threshold value used for test "pass or fail." ... TID $55: Highest emissions-related misfire rate calculated and threshold used.
sounds like you may have a misfire on more then one cylinder,but i'm not a scanner pro at all..i would pull the plugs and at least have a look at them.if you run the truck to long in a rich condition it will clog the cats,

 

[07gtman]

I believe first? RPMS usually read around 750-1000 at low speeds and idle, when accelerating they usually sit around 2000 or above. It seems more difficult lately to get it to second or third, not sure which one because I always remember being able to easily accelerate to 50mph at around 1500 rpm, now I need to push it up to 2000 to get the same result.

this sounds like a misfire also

 

[mbrando1994]

That's the data I got from the car, I'm still not sure how to read it based on what you showed me. Where should I start diagnosing this then? Change plugs? I have that code about the vent solenoid for fuel so could it be a fuel issue? I don't know there to be any vacuum leaks