Bumpy Sensation and AC shuts off

[arabeaa]

i have an explorer 03 4.0L.. first, at speed of 80-100kph there is this intermitent bumpy sensation as if im driving througha speed bumps. it's like thumping, goes away when accelerating, and lately i observed that im also loosing speed wherein not like before, that cruising in a freeway i could easily gain 180kph but now im stuck at max 160kph.. second thing is, AC shuts off at speed of 120kph but comes back after deceleration.what could be the problem? any solutions?

i recently changed oil and air filters, plugs are new...cleaned MAF sensor..

need advise. TIA

 

[waskly]

ac does turn off when the throttle is pressed all the way down, at 180kph i am guessing you're at full throttle. this is normal.

 

[arabeaa]

ac

it wasnt like that before even if im crusing at high speed ac wont shut off..

any ideas about the bumpy sensation?

 

[waskly]

i'm just going to guess here.

you have a misfire you are describing as bumpy, which can cause the ac to turn off since a miss will throw the engine to a high load, and to lower the engine load the pcm will cut out the ac.

but the ac should shut down with wide open throttle or the gas pedal down all the way.

 

[arabeaa]

ac

i hooked it up on an OBD scanner thus no error codes appeared..