So i finally got around to changing my spark plugs, wires, brakes, and valve cover gasket which was leaking. A friend on my mother did all the work, whos been a mechanic for years and is currently building a 70s Camaro (not sure of the year)...anyways after all the work we go for a test and i get this weird vibration in the gas pedal, then it goes away and comes back right after the gears switch. I have an automatic transmission and flooring it makes the vibration more violent, but again it goes away until I am into the next gear! Any suggestions on what the issue is? The guy who did the work says i need new mounts, but i never had this problem until after the work was done.

Update: After driving to work i was able to narrow the vibration down to 1st and 2nd gear up to about 3.5k RPMs. It doesnt seem as bad on 3rd and 4th gear. Could this be due to the car still learning with the new plugs since the gaps on the old ones were horrendous?

 

Bump for a legitimate question!

 

Sounds like a missfire
What kind of plugs were used and what were they gapped to ?

 

Agreed, sounds like a misifre. These cars are picky about spark plugs. Use the NGK BKR5E11, like $2 at most parts stores. Any other plug and you're likely to have problems. And Bosch +2 or +4 plugs, forget it, the car will run horrible.

 

they were NGK BKR5E11, and the gap was within the range suggested in the manual! I was also thinking maybe the cars still learning cause the old plugs we pulled out were gapped at 0.6, WAY over what they are supposed to be, so the mechanic connected some computer thing (lol yeah im a noob) to the car while we drove and was able to see that the fuel trim was being lowered gradually.