Weird Problem CEL

[Miso_Ohio]

First off this is my first post here (sorry for the novel) but I have been watching this forum for a long time. I have a 93 Mx-3 SOHC with over 140,000 miles on it and it is still running. I have had this car since it had under 40,000 on it so I have had it a long time. I have never done much maint. on it except for oil changes, brake pads and rotors, spark plugs and wires, dist caps and air filter.

Recently I thought oh well and commited to do a bunch of long over due work on it. Earlier this year I had a thermostat go, and the replacement went as well so the engine overheated at least 2 times on me then. This contributed (it had already begun before this) to a pretty bad valve Cover gasket leakage which was losing oil about .5 quart every 900-1200 miles or so.

The plan, replace both belts, Timing Belt, Water Pump (could not believe it was still running), valve Cover Gasket, radiater Hoses, O2 sensor (cel going off and on) and spark plus wires (ruined because of the leak). All went as planned and the car seem to running great after tweaking the Timing belt a little (I was off one notch to begin with).

In the past I was having a similar idle problem that every body describes, it will idle normal but a little rough maeaning you could feel it in the stick shift but not in the car. Every once in a while when releasing the gas it would bog down to about 400 RPM and shudder for about a second and then pop back up. This seems to be about the same as before. My dad after the succesful surgery decided to clean ther engine for me at a car wash, well low and behold the CEL light came on and it ran a little rough for about a day until the alrernater dried out.

The CEL light stayed with me for a little over a week, I ran the diagnostics on it and got a code 3 (camshaft sensor). The car appeared to be running fine so I let it be hoping that the sensor would just dry out and I would not have to replace the Dist, or the Throttle sensor, both of wich cost some serious money.

Well today while driving around stop and go traffic my worst fear happened. The idle started going down to almost a stall every time I released it. I did some fancy footwork to keep it from stalling and got it home, I did not want to risk stalling it so far from home and not get it started. About Half way home I noticed the CEL had gone out, that was strange. I got it home and turned it off and then right back on and it purred like a kitten, I have cooled it down and warmed it back up and so far so good.

I am still concerned about a possible cracked head or head gasket because of the earlier overheating so I don't want to invest a lot in this car until I know that has not happened. I don't see any hints of this happening in the oil or coolant (just rusty not oily) so I am biding my time until I know I am not losing oil anymore. My thought on the CEL sensor and the strange ride home was that maybe the culprit sensor dried out and started functioning. This happenend when the ECU was already compensating for it not working and this caused the really bad idle. Once I turned it off and back on the ECU set itself up properly for the functioning sensor.

Question :Does this sound to far fetch or should I be worried about more problems in the near future, my next plan of action is to clean out the Idle control valve but that is about it for now.

[mykel78]

I'd suggest pulling any code it may have. Clear the codes and try it again, see if the CEL comes back on, if so, get the code. Check its oil and coolant levels consistently. and if it's handy, a compression test, to test the head gasket possibility. Best of luck!