QuestionRoland,
I found the EGR valve, and it is operating. I can move it with the screwdriver as you suggested, and with the engine running, I visually confirm that it moves with acceleration. I still took the liberty and squirted some WD-40. Any suggestions?
One thing I failed to mention, is, since replacing the O2 sensors, the car idles normal until you engage the A/C. Other words, as soon as you place the load on the engine, it begins to idle rough.
As for the timing-belt, I will take a look according to your recommendations.
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Followup To
Question -
Roland,
I replaced the rear O2 sensor and now the code 12 is gone. Code 43 is still there, so I am pursuing the detailed information you provided concerning the EGR valve. Thanks.
Question - Is it possible that the timing-belt may have something to do with the poor idle? Just a guess, knowing the mileage and not aware of it being replaced. I understand there is a risk to the head if the timing-belt is not replaced prior to it breaking.
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Followup To
Question -
Roland,
The engine is a 2.0L. It also has 2 O2 sensors, a front one at the exhaust manifold and a back on in further down the exhaust pipe. I replaced the front one, and still have the same problem. I am going to replace the back one.
I still have the same codes (12,43,21,55) I realize that I did not disconnect the battery long enough, after rereading your last message.
One thing I did notice when test driving, was, the check engine light steady flashes when you accelerate from a stop or after slowing down. After the car shifts into the top gear, the flashing stops, but the light remains on. Will keep you posted.
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Followup To
Question -
Roland,
The fault code readout is - 12,43,21,55 (I confirmed this three times)
I looked for the EGR valve, (not sure what I am looking for) and understand that it is suppose to be around the exhaust manifold. I am going to look again today, so any identifiable hints you could provide would be appreciated.
Again, I thank you very much for your willingness to use your knowledge and expertise to assist individuals such as myself. Thanks.
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Followup To
Question -
Hello Roland,
114k miles, has been idling rough, hesitant at take off, engine light has been on, is now off since this issue has grown worse.
Not sure it there is a MAP sensor, not aware of O2 sensor changed, looking for troubleshooting ideas.
I worked with you about six months ago concerning the MAP sensor on a 1993 Chrysler Concorde, and every time I wanted to let you know it worked, your were maxed out. I appreciate the help.
Answer -
Hi Peter,
Thanks for the report on the Concorde.
I would begin with the fault code readout (on-off-on-off-on with the ignition key, the count flashes on the engine light, group in pairs to get codes). Rough idle is often associated with an egr valve that is slightly ajar at idle, so take a look at the valve stem which has a slot you can use to lift and release the valve to observe whether it is opening and closing freely. If not spray the stem with penetrating oil. Other than that, let me know the codes and we'll go from there.
Roland
Answer -
Hi Peter,
The 43 code means that there is a engine misfire problem but it doesn't necessarily distinguish whether it is due to a spark or a mixture issue. But the 21 code is clearly an oxygen sensor problem. I would suggest that you inspect the wires at the oxygen sensor located on the exhaust manifold and if they look o.k. then it would be reasonable to replace that sensor and see if that solves your problems. The 43 may go away and the performance may go back to normal. The egr may not be the problem, and getting the 02 sensor right may be the answer. Be very careful with the wires and tip of the O2 sensor as they are very fragile. And do put the grease on the threads of the sensor, but don't get any on the sensor tip or you will damage its ability to measure the O2 due to grease contamination of its surface.
If you write back with a follow-up, mention which engine is in your car so I can be more specific.
To verify the code situation after you do any replacement of parts, just disconnect the battery for a few minutes and then reconnect. That should erase the memory. Then run the car for a few minutes to see what the new codes are if any. You should only get a 12 and a 55 if everything is back to normal. The 12 means that the power to the engine controller was lost, which of course is the result of disconnecting the battery in order to erase the memory.
Roland
Answer -
Hi Peter,
The egr on that engine is located in the pipe that you will see that comes around the rear of the engine from the exhaust manifold to the base of the throttle body (it appears to run just behind the dipstick for either the engine or trans, I can't tell which but it looks like a dipstick but doesn't show where it is "dipping"). And if that were malfunctioning it would most likely be detected at idle and early acceleration/deceleration when the valve was sticking.
The valve is horizontal in that mounting configuration, so look into the "saddle/cage" that contains the valve stem. You will see a slot in the stem that allows you to watch the motion of the stem when you are idling the car and then try to flick the throttle and watch to see if the stem moves briskly in response. Also try moving the stem by inserting a screwriver tip in the slot and levering it out and in with the engine off. It should move easily out (albeit against the valve closing spring) and close tightly in when you release the stem from the screwdriver tip. Just to be sure, spray a little WD-40 where them stem inters the valve body. Also check for leaks/cracks in the vacuum hoses that go to the solenoid mounted above the top of the saddle/mushroom and the hose from the solenoid to the base of the valve, and also check the electrical connection at the solenoid. The inside of the valve may by cruddy with exhaust byproducts which would prevent it from closing tightly when at idle and that would make for poor idling. You would have to remove the valve from the line and clean the passageway, were that the case. But sometimes the valve stem is just cruddy and spraying WS-40 or other penetrant on the stem where it enters the valve will free up its motion and clear that ajar problem.
Let me know if that helps.
Roland
Answer -
Hi Peter,
The timing belt is recommended for changing at 105,000 miles and if it were beginning to deteriorate it might cause a slippage in the timing relationship of the various sprockets. You can verify the cam shaft sprocket is still in time but you have to use a metal rod inserted through the hole for the no. 1 spark plug because there is no timing scale on the crankshaft pulley. You must rather rotate the crankshaft until the piston gets as high as it will go (note that there are really two such positions relative to the cam (TDC compresssion and TDC exhaust) so if you don't see the timing mark the first try go around again 360 to the next TDC where you should see it. The manual recommends a dial indicator for accuracy in reading when you really get to TDC (which would be the minimum reading on the indicator dial) but for purposes of assessing if you slipped a tooth that may not be necessary. There is an access plug at the top of the outer timing belt cover, so you remove the plug and look in the hole to observe whether the arrow imprinted on the inside surface of the inner timing belt cover is aligned with the slot ground into the camshaft sproket when you are at TDC compression. If it looks to be off about the width of a tooth, then the belt has indeed slipped which would be a good reason for poor idle. But I would check that egr valve stem motion etc. first.
Roland
AnswerHi Peter,
What you described is relevant to the idle issue. Because the idle is o.k. except when the A.C. is on absolves the EGR of any role.
The extra load that the AC compressor puts on the motor needs to be compensated for by an increase in the amount of charge provided to the cylinders. That is done by the powertrain control (engine computer) adjusting the automatic idle control motor so as to increase the air flow thru the throttle body at idle conditions. The AIC motor is located on the throttle body adjacent to the Thottle Position Sensor (the electrical connectors are side-by-side). The AIC has a 4 wire plug, the TPS a three wire plug. My suggestion is that you inspect the wire harness and the plug to the AIC motor to see that there is no damage to the wires from overheating or poor connection at the plug. The other thing you could do is remove the screws that hold the motor in place and extract it far enough to spray a little WD-40 in the hole into which the motor is inserted so as to lubricate the pintel to make sure that it is moving freely. The only reason to not remove it entirely is that if the pentel extends more than 1" you may have to apply some voltages to the four wires to get it to retract enough to put it back into the throttle body. But that is a wrinkle that may be worth dealing with if the AIC motor is just a little sticky and not responding properly to the request to increase the air flow and thus the charge to the engine to make up for the extra load of the compressor.
Roland
