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Hi All,
So right now Im driving a 1998 Dodge Neon R/T 2.0L SOHC 4cyl with the 5 speed manual trans. The car has 180k miles. I know stock the R/Ts had the DOHC but for some reason the previous owner put in a SOHC motor at about 100k miles.
Ever since Ive owned the car the only real issue ive had is a miss in cyl 4 due to no spark. I know my coil pack needs replaced I just havnt had the funding to get to it as my back tires needed replaced.
The other night I was coming home and starting hearing a faint grinding/dragging sound kind of as if the tire was making contact with the fender. Being the road I was on didn’t have many safe places to pull over I figured Id check it when I got home. Closer to home when Id let off the gas and let my speed decay the engine would start bucking/sputtering. It would go away when Id reapply the throttle. About a block from the house the sputtering got worse and the car quit. I tried to start it but it turned into the issue I have now which is a crank/no start.
I had the car towed home and pulled my codes. I was presented with a p0304 (the miss in cyl 4) and a p0340 Camshaft Position Sensor A Circuit. Being that it was dark I did what I could to verify that the sensor was plugged in and I looked at the wire harness for any signs of stripped wires or shorting and didn’t note any.
I decided to go ahead and get a new sensor as Ive been told a bad sensor will causing bucking/stuttering and could result in a crank no start. I did not replace the magnet however.
After replacing the sensor I went to start the car and it still wont start. The computer now presents 2 codes. The P340 and now a P188 Engine Coolant Temp Sensor High Voltage. Stumped I tested for spark but pulling the spark plug wires for cyls 1- 3 and holding them against the valve cover. They spark while the engine cranks. And I can hear the fuel pump activating when the key comes on. (I don’t have a fuel pressure test gauge at this time).
My only guess and this is from my research is that the computer has disabled the injectors as a result of the p340 code. I don’t have a wiring diagram to help me test the wiring. I was wondering if y’all might have any suggestions. The engine does turn over btw.
I am including a brief video for y’all[video]https://www.youtube.com/watch?v=Sj__ATuobvw[/video]
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see if this helps chris. Could not find p188- P0188
http://troubleshootmyvehicle.com/chrysler/2.0L-2.4L/how-to-test-the-cam-sensor-1
http://www.edgeproducts.com/product_images/customer_support_article-pdf-39.pdf
The most common problems I see with those cars for a can’t start is The crank sensor and or wiring ,failed fuel pump, broken/stripped timing belt and engine wiring harness problems.
If it has spark then the next thing to check is for fuel pressure. You will need a fuel pressure gauge to do that. The easiest way to check the timing belt since the cover is a bitch to remove, is to remove the cam sensor and have a helper crank over the engine while you watch the end of the camshaft for rotation.
Okay key on engine off disconnect the connector at the cam sensor.
With the key on test the voltage on the or orange wire you should have 8 volts. Next plug the sensor back in place the positive probe to black with a light blue stripe (you may have to pierce the wire, I HATE doing that but the connector faces down and is really hard to back probe) and place the negative probe on the battery negative (key still on) the meter should read 100 milivolts or less.
If those pass, you next need to see if a signal is passing from the cam sensor to the PCM. Now this is a square wave and cant really be seen without a lab scope, but you can get a reading of the average by putting the positive on the tan/yellow wire and reading the voltage while cranking, it should be around 2.5 volts. IF those check out go to the crank sensor and check it’s 8 volt supply (orange wire) ground (black with light blue stripe) and signal (grey with black stripe).
The crank sensor is right above the oil filter and is notorious for being damaged and having wire damage issues. On the neon since the crank sensor gets it’s 8 volts from the same wire as the cam sensor (same with the ground) I have seen shorted crank sensors ground out the reference line (8 volts) and set a cam sensor code.
Its possible the battery doesn’t have the right voltage to FULLY start. I suggest you check the voltage first. After rereading it sounds like it may need a new computer. But not Certain!!
Had a thought this morning, check your timing belt. Your degrading power level could be a belt that is jumping teeth.
Ill see what I can do to probe the wiring Raistain77 thanks. As an update. I decided to see check on the timing belt by seeing if I have any vacuum while cranking. I unplugged the vac line leading to the LDP to expose the port which is next to the throttle butterfly. I had my helper crank the engine and instead of vacuum I felt pressure and noticed on occasion puffs of white smoke coming out of the port.
My guess is and this is from my research that if the timing belt failed then the valves wont open and close as they should which would result in symptoms such as back pressure in the intake. I guess the only other way to truly verify a timing belt problem is remove the Camsheft sensor again or pull off the valve cover and see if the valves turn with the engine cranking.
[quote=”ChrisR1987″ post=81290]Heres a link to the video I shot Im not sure if it posted here yesterday.
http://www.youtube.com/watch?v=Sj__ATuobvw%5B/quote%5D
Chris you have a broken timing belt. You can tell by the sound of it cranking, if the cam were working the cranking sound would vary and not be a monotone.
The reason you have spark is because the crank sensor is used to fire the plugs, the cam code is because the cam is NOT turning when the crank is turning.
Get a timing belt and pulleys and water pump (the water pump is driven by the belt it is super smart to do both at once.
I PMed you the directions for replacement. Notice how it says to use a special puller to get the damper off. You can either rent one or if you have a regular 3 jaw puller, you can pull the bolt out and slide in a 1/4 extension that is 6″ long and use that to push against (you CANT use the bolt it threads into part of the damper also and you just end up pushing against the pulley and not the crank).
Thanks for the help that’s my guess as well. It would to explain the odd noise I was hearing right before it quit. My question is or my fear is if the belt failed with the engine running and it being and interference engine would that mean my valves are probably toast?
[quote=”ChrisR1987″ post=81295]Thanks for the help that’s my guess as well. It would to explain the odd noise I was hearing right before it quit. My question is or my fear is if the belt failed with the engine running and it being and interference engine would that mean my valves are probably toast?[/quote]
I have done probably 100 timing belt replacements for breaks and only seen one motor that had damage, a Nissan. I have done a dozen Neon belts for breaks and have never seen a SOHC engine damage the valves yet.
If it were mine I would put a belt in it and see. If you have to know before hand you can do this
Get a leak down tester and a compressor, take the valve cover off and than take the rocker train off. Now all valves should be fully closed and you can do a leak down on each cylinder to find out if any valves got bent.
But, I would bet your valves are fine and all you need is a belt.
I wanted to thank everyone for their input. Unfourtnately a couple of days after the car broke down I also lost my job. With a decisive lack of tools (puller, jackstands, torque wrenches, missing a lot of sockets and wrenches) I was at a definite disadvantage of doing the job without any income. So I wound up having to sell the car. I actually traded it for a dirtbike since it was the only half way decent offer I got compared to sitting on a car that I wasn’t sure when Id be able to fix.
[quote=”ChrisR1987″ post=82883]I wanted to thank everyone for their input. Unfourtnately a couple of days after the car broke down I also lost my job. With a decisive lack of tools (puller, jackstands, torque wrenches, missing a lot of sockets and wrenches) I was at a definite disadvantage of doing the job without any income. So I wound up having to sell the car. I actually traded it for a dirtbike since it was the only half way decent offer I got compared to sitting on a car that I wasn’t sure when Id be able to fix.[/quote]
Sorry to hear that. Next time ask if any members live around your area. When I was a moderator over at the Suzuki GS site, I used to drive out to visit members that needed help repairing their bikes.
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