QuestionQUESTION: 1998 Dodge Neon 2 litre SOHC
It is loping after start, just started last time I drove it. Have started it since but not driven it as I am worried it might die on me or not start again. I find I have to press the accelerator on starting now or it seems like it will not start. And it continues to not idle smoothly. Thanks for any help. Have read my Haynes Bible, checked fluid levels, air cleaner, hoses,etc., all seem fine. I am not a mechanic and would like to be able to relay to one what might be wrong.
ANSWER: I would check the egr valve. The egr valve on the 2.0 is located at the rear of the engine at the corner that is nearest to the driver (if this is a left hand drive vehicle, otherwise nearest to the passenger). It has two pipes: one coming from the exhaust manifold on the firewall side of the engine compartment, and the other going to the throttle body where the incoming air enters the intake manifold on the side of the engine that faces the front of the vehicle. It has a vacuum-line operated solenoid attached to it by a couple of rubber vacuum hoses. The main vacuum line to the solenoid comes from the power brake canister which sits on the firewall directly in front of the driver (again if this is a left hand drive vehicle, in any case its is part of the brake master cylinder unit). So you can trace that vacuum line to the solenoid and then to the egr valve itself. The valve is mounted horizontally and you will see a round fitting on the top and a saddle that supports it with openings, inside which you will see a metal rod with a slot that moves back and forth horizontally. That rod is the valve stem which is attached to the valve inside the main housing which opens and closes the connection between the two pipes.
One reason why an engine behaves as yours does is that the valve is stuck ajar. So if you take a flat-tip screwdriver and insert it in the slot you can lever the valve stem out (againt spring resistance) and in to check that it moves easily. It is helpful to use a spray can of pentrating fluid (WD-40) to spray the valve stem where it enters the valve so as to loosen up any stickiness. The valve should close tightly against its stop when the engine is at rest, so that the valve is fully closed when you then try to start the engine. Otherwise it will recirculate exhaust gas which dilutes the mixture excessively and prevent starting. Only when the engine is running should you see the valve stem open in response to revving up the engine to 2500 rpm and then close quickly when you close the throttle valve. That motion is controlled by the solenoid and vacuum supply lines.
The other thing to do is get a fault code readout, often it will be free at an Autozone parts store. Let me know what codes you get and we'll go from there.
Roland
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QUESTION: As a follow-up, thank you for your response but now I have found that there is oil in the spark plug wells. I have done some checking and have found that it is probably the valve seals and possibly o-rings at the bottom of the spark plug wells. Is this all that it might be? Anything else I should be checking. I haven't driven the car since I had the loping problem as I don't wish to break down somewhere.
ANSWER: Hi Lorie,
While I personally have not changed spark plugs on the 2.0L engine, if there is oil in the plug wells then I would doubt that has anything to do with the engine's valve seals as when they leak they let oil into the combustion chamber, not the spark plug wells. However, the O-rings on the spark plug tubes are more likely not sealing tightly and that is the case that is the most likely reason for their being oil in the wells. So I would remove the valve covers and put a new oil seal on each of the 4 spark tubes holes in the cover. Then also get a new valve cover gasket, and the install the valve cover and tighten the fasteners to spec. (9 foot-pounds). That should solve the oil issue in the wells.
Don't overlook the possibility of the egr valve being an issue as well.
Of course you can get a fault code readout at an Autozone parts store for free in most cases and that may give you a clue about the loping. If you get a 0300-0304 code (engine 'misfiring') that woule likely be due to the oil issue in the tube wells.
Let me know if you get any other fault codes.
Roland
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QUESTION: I am getting a code 23, (intake air temp sensor out of range). How do I repair this?
AnswerHi Lorie,
Look on the left side of the engine compartment on the side of the air hose that comes from the front of the car to the engine where you will find the sensor close to the power distribution box. It has a 2-wire connector (violet/light green, black/light blue). Let the tab on the connector to remove that, and then remove the sensor from the air duct.
Roland
