QuestionHey Anthony,
Thanks for the info last time. The persistant miss turned into a bad head gasket and bad head. And some crank shaft retreading.Includes timing water pump, head, gasket, pulleys, new crank shaft bolt, etc.($2571) I recently bought the car like this without knowing? After head job engine was running like new Idle was perfect rpms. I blew a water hose a few days later, hose runs in to the fire wall. I replaced it and engine runs fine but while replacing hose i diconnected some module(device) that mounts on the right top of the head. Battery was still hooked up while i did this. What did I disconnect? Since then, the engine light came on and codes read 37 and of course 55, but 37 is park/neutral switch and says to replace PCM. My idle is super high at 2000 2500 and moves up and down alot while idling. What did I do? I know the PCM is performance control module but wouldnt be like the ICM? My car didnt give codes for too little or too much air so could it still be the IAC? Whats the difference And do you think I should go ahead and replace these things if I dont know the true history of this car. What should I start with to correct the IDLE problem? Can you get these parts remanufactured/rebuilt?And if so whats the estimate for parts like that? Also my transmission has a faint tapping sound but shifts good no grinds acceleration is fine for a 115K car, is that a bearring? NEVER CHANGED TRANNY FLUID YET!! Thanks Anthony. Appreciate your time.
Tony
Followup To
Question -
Hey Anthony, I have a 95 Eclipse GS 5spd.I need to know some reasons why engine would idle rough(small miss). Car has had complete tune up. battery,plugs,wires,distrib coil,air filter,oil change. When idling ranges(moves up and down) 750-900rpms. Should I change timing belt? or adjust idle torque? What about head gasket? Fuel Filter? There is a little bit of white smoke at times?Check engine light came on but still starts and runs but feels sluggish at accerleration at times(sometimes). Autozone said they couldnt run codes due to my late model. What do you think will improve idling? Also engine coolant always overflows, seems to run hot but not overheat. Faulty thermostat i think? What do you think of all this? Thanks for your time! Can you send response to Citygrown@yahoo.com
Tony
Answer -
Tony,
Sorry, but I'm not allowed to send a response to any other email except for that indicated by you when you sent me this question.
A bouncing RPM reading can indicate a worn Idle Air Control (IAC) motor. It regulates your idle speed and should keep it steady at around 750-800 RPMs. But your idle is not moving too much, so it's probably not that big of an issue right now.
But what is a big issue is if your current timing belt (and balance belt) has over 60,000 miles on it. Get it replaced ASAP if you're near that mileage on those belts. With a timing belt replacement, your tensioner and water pump should also be replaced. A weak water pump may also be the cause for your overheating. But it's a good idea to get a coolant flush, replace your thermostat, and radiator cap along with your timing belt and water pump replacements. You may even want to consider replacing your upper and lower radiator hoses if you're paranoid like me ;-)
If your head gasket was at fault, your car may not even start or would run extremely poorly. But any garage can perform a compression check to verify your head gasket is ok. Though replacing your fuel filter every couple years or 25,000 miles is always a good idea. Remember to replace your transmission fluid every 35k-45k miles as well.
Good luck!
AnswerTony,
Code 37 does indeed represent the 'Park/Neutral Switch'. It's strange that you're getting this code because usually that switch is associated with automatic transmissions. That switch is tied into the starter ignition and brake pedal, and prevents a car from starting if the car is not in Park/Neurtral and the brake pedal is depressed. Strange you'd get this code, knowing that you have a manual transmission.
But yes, if a 37 code is what is being thrown, the recommended fix from Mitsubishi is to replace the PCM. PCM actually starnds for Powertrain Control Module. It is your car's main computer.
If by the 'right' side of the engine, you mean the passenger side, then there could have been a variety of items you may have moved. On the top most of the right side of the head is the cam angle sensor. If that was moved, your timing would be way off, you'd idle poorly, and your check engine light would come on. I don't see how it would throw code 37, but it would definitely throw a couple codes. You may have disturbed an emissions valve, fuel pump switch, or even your Idle Air Control (IAC) motor; the item I mentioned in my previous response. If you could somehow get me a picture to see, I'd be able to let you know what it is. Since the IAC is not a sensor, it usually will not throw an error code.
If you want to save some big money, you can diagnose some of those components yourself. I would recommend visiting your local auto parts store and picking up a service manual for your car. Both Haynes and Chiltons makes a service manual for your car, and they provide very good instructions on checking most your components, including your IAC. Your idle problem may very well be with your IAC. Check that out first.
You can find rebuilt IAC motors. A new one will cost around $100-$120 from the dealership (part # M04796503). Before having any transmission work done, get the fluid changed. That may help with the tapping noise.
Good luck!
