One problem im having is, it seems like while the car is in drive, it idles rough, like it vibrates in a very fast repetitive way. Also, while driving on the freeway, the rpms are bouncing over the place, but it doesnt affect the speed that much. What is going on there? It seems to do it more at night. Its got a 2.4 motor.

1 more thing, is there any way to quiet down the noisy engine? its got 185k on it but the motor has a loud tone to it.

thanks guys.

 

Has any work been done to the engine as of late? Just guessing the balance shaft maybe off and causing the vibration.

 

Define that loud tone. AT that mileage I would start looking at the timing or motor mounts. I had a compact GM car that sounded like a Diesel because of the chain. Changed it and it was almost Caddy like

 

theres no ticking or knocking.. its just not quiet lol. Doesnt bother me.. i realize its an high mileage engine so it doesnt bother me. the rpms bouncing and vibrations is whats bothering me more. rpms bouncing problems seems to come and go.. 1 day itll drive fine and the next itll act up bad. Is a transmission fluid change needed or is the problem deeper?

 

I would say that it's your vacuum lines or an idle sensor. Check those 2 out before you look at the tranny. I believe when the tranny acts up it starts hesitating and clunking more than "random rpm". My Jeep did that, and didn't do the RPM thing. I had an RPM problem, but that ended up being a loose connection near the throttle. Couldn't hurt to check that either.

 

I'm noticing that when the rpms move around, itll be at about 2500ish then itll go up to 2900 then hold there for a few secons then drop. Only does it on highway driving at 60-70 mph

I took the idle sensor out and it was covered in carbon so i just cleaned it with a rag and put it back in, idk if that was the proper way to clean it but whatever, didnt change anything. also fixed a cracked line. Didnt do anything

How about the TPS or the cat converter? or battery? Also i noticed when i took the center spark plugs out, the threads where covered in oil.

LMK if theres any input. This problem is annoying.