Hey guys

I have been having some issues with my 2006 MC 3.5L V6 k. at idle the engine almost stalls, doesn't ever shut off, but it drops RPM's too the point I think i might shut off. also while cruising the car, especially around 2000 rpm, will drop down to 1800 and back to 200 repeatedly. i was having some issues with the car this spring witch through out a code for the TPS. i replaced the throttle body, and the issues got better for a bit, but are now getting worse. so far this is what i have done:

New mass airflow sensor
new air filter
new spark plugs and wires
checked for vacuum leaks, none found
i have noticed the MPG going down a bit, and it seems to be burning oil, but not leaking, appears to have no leaks.

I am open to any Ideas

Thanks!!!!

 

could be a bad cam or crank sensor. the dropping of the rpms while cruising is normally what it does when you have a misfire. have you had you car scanned better than just a little ole' obII scanner? i had a bad wire in the boot this year and caused my car to screw up real bad the more i drove it. even tho they were brand new. so you could double check your wires. i would take it to a trusty mechanic and have them check over it with their scanner while idling and driving to see whats going on in the engine. knowing which cylinder is misfiring will help to figure out where the problem is as well. if its only one cyl and not a cpl or more than check the wire or maybe thats the cyl with the weak valve or piston. if its 2 and they run off the same coil pack then the coil could be the culprit. how many miles are on the engine? weak valves usually are the culprit to burning oil. But so can worn pistons. depending on miles, and previous care to the car. another good thing to replace is the fuel filter. its a cheap easy fix that never hurts to replace.

 

check your Cat? mine was bad and clogged and made it run like **** and mpg down also no acceleration and no passing gear! runs like a scolded dog now!!

 

i just passed 130,000. i haven't had it in to be checked but i will try now. also where is the furl filter on the 06 MC? i have been trying to figure it out, but have been told it is built into the fuel pump.