Hi to all, first post, I have a problem I hope someone can help with. My daughter has a 2002 Galant 2.4L 4 cyl auto. 111,000 miles. all of the sudden the other day, while at a traffic light, it started running rough, the check engine light came on and it started pinging (detonation)very badly on acceleration to the point where it is barely driveable. We have it down to the local mechanic and he is telling us the motor is junk. says cyl1 and 2 have 170lbs of compressiion and 3 and 4 have only 80 and this is the problem. suggests new motor for $2500. The motor idles ok , doesnot skip, doesnot smoke, tailpie is clean,the pinging gets worse as the motor heats up and has been trouble free until now. It acts just like the timing is advanced all the way. I feel it is in the ignition somewhere. any advice or suggestions are welcome
thanks

 

STOP ANY WORK FROM BIENG DONE NOW!!!!!!!!! if i had lots of money to bet i would say your tube seals are leaking oil into the spark plug tubes and making the car miss on acceleration. take this vehicle somewhere else to be diagnosed, a mitsubishi dealer would be best. they will give you a proper diagnosis. the 2.4 litre engine has been one of the most reliable engines mitsubishi has ever made. tube seals leaking is very common. it causes all the symptoms your describing. you have to remove the valve cover to replace the tube seals, also the oil ruins the coil boots, and the plug wires. this is a realitively easy thing to fix, should be done in 1 day. do yourself favor and get a 2nd opinion from the dealer. you wont regret it.

 

Well went to the dealer. they put new plugs , wires, and some ignition part (forget the name right now) and $350 later it still pings uncontrollably. (using premium, octane boost) It doesn't run rough any longer but pings loudly. they tell me the compression in 1 and 2 is 180lbs or so and 3 and 4 is 80-90lbs and that's the trouble. they wanted to do a valve job for an additional $1500. NO WAY I don't see how low compression in a couple cylinders can cause this problem. So far I have $500 into and it still has issues. DAAMMM!!!