Driving issue, need help!

[kdon1124]

hey guys im new here but i need help if its posted before send me that way but i have an 02 mazda protege 2.0l when driving from a stop in first gear the start is fine but around 2500 rpms the car starts to jerk violently as it goes up and up so i have to back off the throttle completely and press it again and hope it doesnt happen. if it stops and i go into second gear around the same rpms it starts to jerk again and then third it does it a very little bit. but 4th and 5th are fine. is this a clutch issue, or mount issue or something in the spark? i need to know because this car is a piece of ****. i mean i love the proteges but all this one does is leave me stranded on the side of the road. but im working on fixing it!

thank you

[meGrimlock]

when you say jerk violently, is this vibrations you feel from the engine, or maybe somewhere else like the suspension? assuming its a manual transmission, are you still in gear when this happens or when you are shifting? does it happen only when driving or will it happen in a neutral standstill?

[kdon1124]

it would be when im in gear and would feel like i had a horrible shift although i wouldnt be shifting. yes its manual but after further investigations i noticed that 3 of my 4 engine mounts are badly damaged so im almost sure it is that! but after i get the new ones on ill see if that cures the problem, thank you!

[meGrimlock]

checking the sparks is pretty easy, checking the coils and wires too if you have a multimeter is a cakewalk. however it doesn't sound like it would be the culprit. check for a vacuum leak, maybe the air intake hose. 2 mounts in the front and rear of the engine bay are more prone to failure. the transmission mount sees very little back/forth movement compared to the rest, so it is most likely ok.

the 3rd mount (nearside or right side) is designed to separate, so while it looks cracked, it may not be. this one is fluid filled so I would check for fluid leak around the mount. it'll be dark, resembling old steering fluid. if you see this and you don't have a steering leak, its probably a busted mount: