Overheating and rough running engine?

nerdifiedgeek · #1 (**permalink**) 08-28-09, 09:02 PM

This is a long story, but first my car started with the power seeming to drain overnight, which may have nothing to do with the problem it is having now. When I was driving it home one day though the engine seemed to suddenly slip or something that cause it to not want to stay up to the 55mph speed limit. I slowly drove it home, and by the time I got it home which was only a half mile down the road, the engine was shaking really bad. I got it parked and let it run for a while, and I just watched the engine shaking hard. I finally shut it off, then the battery seemed like it isn't draining as bad. Sometimes I have to jump it still, sometimes I don't. However now when I turn it on it still shakes really bad. When I drive it, it sometimes hits a "barrier" at 45 MPH where it makes a really rough noise and won't go any faster, other times if I accelerate really slowly it's fine. When I drive it though it over heats very quickly. Within just 5 minutes or so of driving it. After I drive it and go to park it the oil pressure is also extremely low, and runs really rough and almost acts like it's going to stall. My initial assumption is a blown head gasket however I've checked the coolant and oil and don't notice any mixture in them. I also checked for foam in the engine oil cap and such and haven't found anything.

Also one time when the engine got really hot it popped the check engine light. I checked the code and it was a couple missfires in the cylinders, and Mass Air Flow Sensor High Input whatever that means. I think there might have been another code that popped but I can't remember what it was.

eastsidercaddy · #2 (**permalink**) 08-28-09, 10:56 PM

i experienced similar happenings...you could need a new thermostat, simply because i changed my spark plugs once and it started running hot..coincidence. Also, you spark plug wired that run from the coil pack are probably loose. My misfire was becuase of this. Look behind the drivers side of the engine without cranking it up, press down on the coil plugs on top, you should be able to get to them without to much hassle. Press down and make sure they are secure. I also recommend changing you plugs while your at it. Crank the car up and it should be good. Also, your MAF my be going bad. Try that out and we'll see what's going on with it.

R-Caddy · #3 (**permalink**) 08-29-09, 02:10 PM

The rough running sounds like the faulty MAF

nerdifiedgeek · #4 (**permalink**) 08-29-09, 04:00 PM

Checked the coil plugs and they appeared fine. I took the MAF off and it appeared perfectly clean, however the dumb person that I am touched the sensor piece inside of it and broke a piece off. I put the MAF back in and it's not acting any different than it was. So possibly the MAF was not working to begin with?

Note: I put some Fuel Injector cleaner in it this morning and let it run for a while as well. Haven't noticed a difference.

SkullV · #5 (**permalink**) 09-03-09, 11:47 PM

Quote:

Originally Posted by nerdifiedgeek

Checked the coil plugs and they appeared fine. I took the MAF off and it appeared perfectly clean, however the dumb person that I am touched the sensor piece inside of it and broke a piece off. I put the MAF back in and it's not acting any different than it was. So possibly the MAF was not working to begin with?

Note: I put some Fuel Injector cleaner in it this morning and let it run for a while as well. Haven't noticed a difference.

Yes, the MAF is faulty if you broke a heater wire off and there is nothing different. I am not sure about older GM PCM's but on the newer ones when the maf goes dead it reverts to running off the VE table which unless properly tuned can give weak power and poor idle quality.

nerdifiedgeek · #6 (**permalink**) 09-08-09, 05:48 PM

I replaced the MAF today, and it still didn't fix the problem. Drove it for a couple minutes, and by the time I got back it was overheating and running super rough at lower RPM. The lights on the radio were flickering too which tends to say there may be an alternator problem as well. Once I shut the car off it was completely dead. No battery whatsoever left. I also had codes pop. 004 which I can't find online but it said something about the fuel circuit high , 1100 Mass Air Flow Sensor High Input, and several cylinder misfires.