Plymouth Neon

2007 Plymouth Neon All Part Groups   

what will make the car not start? have already checked starter, battery, and cables. there is no noise at all when you turn the key. the lights and radio work.

You will need to do some testing under the hood to determine the problem.

Use a voltmeter at the starter to check for voltage. Hold the ground wire of your meter on the starter. There should be 10v+ on the large wire while your assistant tries to start the car. There should also be 10v+ on the little wire while your assistant tries to start the car.

If both test are OK, you have a bad starter. If both tests are low, check for a poor ground connection, going back to the battery. If only the large wire has low/no voltage, test it back to the battery. If the small wire has no/low voltage, look at a bad ignition switch, alarm problem, neutral safety switch, or related wiring.

2001 Plymouth Neon Ignition System   

Key cannot be removed and transmission freely goes into gear without application of the brake pedal

The only thing that you can check is the linkage for the shifter and the brake pedal actuation switch under the dash at the bottom of the column.Also check the fuses.Because this is an unusual problem, I would look for something out of the ordinary, an accident recently, or did some one kick up under the dash? As this is somewhat a saftey item, if you are not well versed in this kind of repair, you may want to enlist the help of a Chrysler Tech.

2000 Plymouth Neon All Part Groups   

my oil light has come on about 4 times. I took it to a car repair to check the oil, it was full. What are the possible diagnosises for the vehicle and approximate prices for repair?

Oil pressure sending unit is probably bad. I don't know the cost, but the part should be relatively inexpensive.

I don't understand "oil pressure" sending unit - what is that? The sensor light or an actual functional problem and what part are you referring to?

are you there?

At which rpm's does the oil light come on, just at low rpm's or while driving?

The 'oil pressure sending unit' is a device located on the engine that communicates oil pressure from the engine back to the gauge. If this is malfunctioning it can falsely trigger the oil light.

Do you hear any engine noise when the light comes on? If you do this would indicate the oil pressure is indeed low. No extra engine noise indicates that oil pressure may not be low, and it may simply be a problem with the sending unit.

Let me know what sounds you hear and at which engine rpm's the light turns on, and we'll continue.

Usually the car is while I'm stopped at a light or when I'm idling. The only noise that is heard is the "ding" when the light comes on.

If it is the the "oil pressure sending unit" is it ok to drive or will it ruin the engine?

are you there?

If there is no engine noise (which there certainly would be with no oil pressure) it can be about three things.

One the oil sending unit is under-reporting oil pressure at low rpm's, causing the light to come on.

Two is when the engine (oil pump, bearings) is worn and/or oil system is dirty (pick-up screen for pump) in which case the sending unit will correctly report lower than desired oil pressure (albeit not low enough to cause engine noise from complete lack of pressure).

Three, and this is the most often overlooked cause by professionals, is when the idle speed is dropping to low. This can be from a dirty idle air control valve or simply a dirty throttle blade. When the engine idle below specs, it will create less oil pressure, sometimes to the point of setting off the 'Oil Light.'

The oil pressure sending unit, if bad because it is falsely reporting low oil pressure, will not cause any engine damage (simply a false alarm).

Next time this happens, while in a safe environment, shift to neutral with your foot on the brake, and press the gas pedal slightly to raise the rpm's. Does raising the rpm's cause the light to go off?

Hello,

I've re-opened this question at the customer's request.

Mark,
Site Admin.

My oil light has come on about 4 times....I had the oil checked - it's full - what could be the problem, what type of parts for repair and approx how much?

Did you get my previous reply?

I doubt you currently have a serious problem, and faulty diagnosis could lead to unnecessary parts replacement.

It should cost you between 1/2 and 1 hours labor to diagnose the problem. What the shop will do is install a mechanical gauge and compare the actual oil pressure readings at the engine compared to what the sending unit is reporting.

A faulty sending unit would be $75-150 including diagnostics and replacement (an aftermarket part typically cost a fraction of the 'repair' cost). Labor costs also vary significantly.

2000 Plymouth Neon Engine   

The engine tries to start but doesn't. It is no different with starting fluid so I don't believe it is a fuel problem. I have a ScanGaugeII plugged in and there are no trouble codes listed.

I have checked for spark at the plugs and it is good. The plugs are only about a month old. I changed them because I was having the same problem and it seemed to fix it then. I put the #1 piston on top and the mark on the timing pulley was within 3/16 in. of the mark on the cover. I have been running with the ScanGaugeII since then and no trouble codes have ever shown up. I am going to purchase a crankshaft sensor and a camshaft sensor and try that next. I don't understand why a trouble code doesn't show up. Maybe the ScanGauge is a piece of crap. I will keep trying till I find out the problem. I am looking forward to some suggestions from you guys. Thank you, John

I have installed both sensors and the problem still exists. I think the only thing left to do is change the timing belt and see if it had jumped a tooth. There are 93,000 miles on the car and according to the book it should be good for 110,000 miles before changing the timing belt. The car hasn't been run hard so I was leaning away from that alternative, but now I don't know what else to go for. I am still waiting for suggestions. I won't have time to do anymore on it till next weekend.

Timing belt is certainly a possibility if it is getting spark/fuel just getting it at wrong time!
Try to just remove the cover first and see if the marks line up but you are right, the service interval for the belt is coming up...and they are inexpensive...

Thank you for your reply. I will check that before I remove the belt. If the marks should be in alignment, where do I look then? I won't have time to do anything before the weekend. Have a good day.

I have removed the timimg belt cover and the timing marks DO line up. Where do I go from here? The belt looks good, no sign of wear or looseness.

Back to the basics..do a compression test
let me know the numbers *wet& dry test*

We had previously run a dry compression test. #1 cyl had 175 lbs and #4 had 225 lbs. #2 & #3 had in the neighborhood of 200 lbs. We will do it over, both wet and dry and record the numbers. Thank you, John

We have done the compression checks. For some reason they aren't as high as they were the other day, but here they are.

#1 DRY #2 DRY #3 Dry #4 DRY
160 lbs 150 lbs 155 lbs 155 lbs

#1 WET #2 WET #3 WET #4 WET
180 lbs 165 lbs 165 lbs 175 lbs

These reading are on the low side, but I think it should still run. What do you think?

Shows a loss of compression dueto worn rings,but the big difference from first test is disconcerning,I wonder if engine
was very carboned up at that point.Those figures were even higher than new specifications!
Might try a different scanner. I use one from Snap On

We are in the process of replacing the water pump, timing belt and oil pump since we are in that far. I removed the plugs from the PCM and found oil in one of them. I don't know how it got there since there was no sign of oil on the outside. I wonder if maybe a transformer in side the unit had failed. I am going to see if I can find another PCM in a junk yard before ordering a new one for $235 plus $80 to program it. I would think one would work if it came from the same model car. What do you think? If the PCM were bad, that would explain it not giving a problem code, right?

yes there should be no oil in pcm,
Is car turbo? same model car should work.see if you can match up the Service #
on tag

I have only been to one junk yard, but there were 4 PCM's to check out. All 4 had oil in them. I still have other places to try, but haven't had time to go yet. Thank you for your reply. John

We have the car back together with the PCM from the same model car, but it started and quit after a few seconds. I did this several times. I was wondering if maybe the key chip needed programmed for the new PCM. I don't know anything about that. I have heard that there is something in the keyswitch also that could be bad and not allow the chip to work. Have you heard anything about that? I am about ready to give up on this project. It certainly has been a challenge.

John

Yes some cars have a security key code (VATS or Vehicle Anti Theft System) that may cause the problem

1998 Plymouth Neon Heating / Cooling System Overheating When accelerating When warm 

Just replaced thermostat and water pump. Continues to overheat after reaching speed more than 55 mph. Turn on heater and does not come down. Does not overheat while idling or running around town. What else could be the problem?

These cars are well known for failing head gaskets. A radiator shop can 'sniff' the coolant to see if combustion gases are present.

Make sure cooling system is full and no air was left in system. Also that cooling fan turns on when it's supposed to.

1998 Plymouth Neon Engine Overheating Happens sometimes No pattern

My Neon (98 Expresso) overheated at low speed (around town) a couple days ago. I checked the coolant, and added approx 1 gal antifreeze/water. Seemed to help, but it did it again yesterday. I think I need to replace the thermostat (most common problem, right?) I was going to try to purge the air(if any) out of the system first, though. Any suggestions? Also, I'm not sure if my fans come on. Thanks for your help.

The first thing to check for is a coolant leak. Then if there are no leaks you would check the cooling fans. I recommend taking the car to a garage that you have trust in to not rip you off. If you have a Tire Kingdom or Merchants Tire or Big O in your area, they are usually reliable and fair priced. Things can get expensive if you misdiagnose your problem and end up warping or cracking the cylinder head. If I can assist you any further you can Email me directly at [redacted] upon accepting this answer. Good Luck and thank you for your question.

Walt Boyer
ASE Master Tech

1998 Plymouth Neon Fuel System Won't Start When starting Always

I am trying to figure out what could be wrong with my 1998 Plymouth Neon. It has 140,000 miles on it and ran great until a few months ago. All of a sudden it seemed to have a large loss of power...I could put the pedal down and it seemed the acceleration was very sluggish compared to usual...then it got to the point the accelerator seemed to "pump itself" almost when coasting to a stop at a red light. Now I can't get it to start. Basically I turned it once...and it seemed to "turn-over" but the whole car kind of shook/studdered and then just died. Now it seems like it wants to turn over but just can't get there...does this sound like a possible fuel problem? And how would I check to find out? Thanks!

you can do a fuel pressure test on your intake with a guage to check if your system is holding also check the fuel pressure regulator and another possibility would be
your fuel filters particularly the one in the fuel tank
I agree it sounds like a fuel pressure problem
Hope this helps

1997 Plymouth Neon Ignition System Won't Start When stopped Always

Car will only start by popping the clutch. Battery and starter are good?

You have not provided near enough info to troubleshoot this problem. Do the lights work? What if any noises does the engine make when you turn the key? Has this problem started suddenly or gotten worse over time? Provide everything you can and I am sure we can help you fix this. Al

1997 Plymouth Neon Ignition System   

car died while driving, now won't start, found shorted wiring, replaced cam and crank sensor, timing belt recently replaced, still won't start, cranks good, trys to start at times

has 150 psi compression all 4 cyl.
has fuel at injectors and has spark at plugs
shop found shorted melted wiring, wire replaced prior to cam and crank sensors

Hello, What circuits were involved with the burned wiring? What engine please? How strong is the spark from the coil? Have you cleaned the spark plugs? Are they fuel soaked?

Roger

1997 Plymouth Neon Fuel System   

I would like a wiring diagram for the fuel pump. What is the automatic fuel pump shut off feature for this car?

Hello, I'll need an email address to send the diagram to you. What is your address please?

I don't recall an automatic fuel shut off feature on this model....let's see if the wiring diagram shows one.

Roger

[redacted]

Thank you, I'll send the diagram.

Roger

1996 Plymouth Neon Fuel System Malfunction When starting 

I do not seem to be getting any fuel to the the engine. I can hear the fuel pump turning on in the tank, but it does not appear to be getting fuel to the engine. This particular model does have an external filter even thought according to the repair manual it is not supposed to have one. What would cause no fuel delivery to the engine if the pump appears to be working. The car was running fine. I turned it off when I got to work, when I went to restart it it would not start. Also when doing some checking to see if it was getting spark, I found oil in the spark plug housing. How would oil get into the housing?

You did not mention if you had any spark or not. There is a possibility that the filter in the gas tank is clogged. There is a possibility the rubberfuel line from the fuel pump to the metal fuel line (inside the fuel tank) has failed. It is possible that your timing belt has failed and that is why the car wont start. As far as the oil in the spark plug holes the valve cover gasket is worn out and needs replaced. Lets cover what I have already given you and we can go from there. Al

Al..The engine is getting spark. but when I disconnected the fuel line to the engine and turn the pump on no gas was coming out. So I disconnected the fuel line just after the external fuel filter and turned the pump on, still no gas coming out of the line. I will be removing the external filter later in the day to so if fuel will come directly out of the tank before the filter.. Thanks for your help so far Al.

1996 Plymouth Neon Heating / Cooling System Failing When troubleshooting Always

recently Ihad to remove the radiator along with the condenser from my neon in order to replace the starter. I have reinstalled everything and my orignal problem is solved. My new problem is getting the air conditioning working again. I have tried toadd freon (134-a) back into the system but now the compressor, or somewhere around there vents freon intermittently.

I recommend reclaiming the refrigerant, vacuuming the system out, installing the proper amount of refrigerant. Then, it should also be leak tested. Check every connection you had apart.

Leaks can come from pinched o-rings, or the system will blow off excess freon if it overfilled, and it will not cool properly.

what is the correct amount of refridgerant for a 1996 plymouth neon and can I purchase o-rings at any automotive store?

Most automotive stores sell the O-rings. 28 oz of R134a is the correct amount.

It will be friday or saturday before I will have time to work on the car again. I'll let you know how it turns out.

It is recommended to vacuum the system to at least 28"hg for at least 20 minutes. That removes all the air and moisture from the system for best performance.

1996 Plymouth Neon All Part Groups Smelling When driving No pattern

I have a burning smell coming from my car, and the car seem to stall, and doesn't pick up speed, also the speedometer works sometime what should I do

hello what can I do about the burning smell

Where does the smell come from... the engine area, exhaust, dash, heater, etc? And what does it smell like?

Does the check engine light come on when the speedometer quits working? Or is the check engine light on at anytime while the engine is running?

I check engine light doesn't come on when the speedomoter quits the engine light came on a couple of times and then it turned its self off. The smell, smell like wire burning

An inspection will need to be done to determine which area the smell is coming from, there is no short cut around this.

You should visit Advance Auto or Autozone and have the codes read (no charge) to see which codes appeared before. Let me know what they are.

When I am driving up a hill when I get to the top my car seems to turn its self off. When I tried to put my foot on the gas pedal my car doesn't move I have to do it at least more than once to make it move and when I do the car seems to go back a little then move forward. and it only happens on hills. why?

1996 Plymouth Neon Engine   

1996 plymouth neon, sohc, automatic transmission, 200k mileage.
Check engine light on. Code says oxygen sensor. Changed both. Uses less gas, runs better.
Changed converter. Lot more power, runs better.
Still have engine light on with oxygen sensor code.
After startup, revs slightly and drops.
If I drive cold for about 5 minutes, and shut off, come back in 30 minutes and start the engine light goes off for about 7 minutes of driving. Runs like new. Then light comes back on. less power.
Do you think this is the computer?
Thanks,
Brett

The computer (PCM) is possible, but not necessarily probable.

What the P0XXX trouble code you are getting? If you don't have it visit Advance Auto or Autozone and they'll access the code for you. I'll need the actual trouble and not the desription of the trouble code. Examples, P0122, P0135, etc.

BTW, I assume you cleared the codes after parts replacement (by disconnecting the negative battery cable for a few minutes). If you haven't don't do so now, or it will erase the codes before you can get them read."

1996 Plymouth Neon Electrical / Lighting Systems   

battery light came on. Buzzing noise heard inside car. Noise is coming from fuse box. I assume it's a relay? or dimmer switch? when I turn light switch counter clockwise, buzzing noise stops. Car will not start, started several hours ago.

You will need to have the charging system checked. Most autoparts stores will check the charging system free of charge. Some will also charge your dead battery free of charge (Advance and probably Autozone). Call ahead. You need to address the charging problem (low voltage) and see if the other problems go away. Let me know what you find.

1996 Plymouth Neon All Part Groups   

Can you tell me where the intake air sensor is located?

Mounted in the intake manifold on the front, upper, driver's side of the engine.

1995 Plymouth Neon Electrical / Lighting Systems Malfunction When coasting No pattern

the torque converter clutch circuit electrical is what is wrong with my car's transmission. It could be that or just the sensor. I would like to replace the sensor, but have no clue where it is. could you let me know where and what tools would be best, or if it is even worth it? I don't have the money for a new transmission let alone a new car, so any tips you may have for me to keep this car going are helpful. Thank you.

Are you having problems with the transmission shifting?

Did you perform the key on/off method to retrieve trouble codes and get a code that led to this question?

1995 Plymouth Neon Engine Vibration Happens sometimes No pattern

This also revs,chugs, and the radiator electric fan cylces on - off - on - off when the fan comes on the engine chugs, when the fan goes off it revs (relatively smooth) these cycles are about 5-10 seconds apart.

Do you get a check engine light while the engine is running?

Any smoke from the exhaust, if yes what color is it?

Are you losing any coolant?

the check engine light comes on when running or idling. No apparent smoke from exhaust

See if self diagnosis will work, they should and are simple to do.

Turn the key ON, OFF, ON, OFF and ON again(there times within five seconds)(ON is to where the dashlight come on not engine cranking). The check engine light will flash the codes in the following sequence-

flash/flash PAUSE flash/flash/flash= 23
The first set of 'flashes' is the ones place and the second is the tens places.

Let me know which trouble codes you find.

Hi Doug, ..Just got back from work.
the codes I read were and are still 12,43,55.
12 bothers me the most becuse this is my daughter's car and I haven't any knowledge of the battery being disconnected . Is this a PCM problem and if it is ...where is it located and is it possible to diagnose without expensive meters and equipment ?

12 is meaningless, it almost always shows on Chrysler products.

43 is the code of most interest. Check the coil to begin with. Most auto-parts stores will check the coil free of charge. Have them measure ohms on your coil vs a new one and see what the differences are.

If you do have a problem with PCM it cannot really be diagnosed. The most common way to diagnose a PCM as bad is by eliminating everything else on the circuit. There are also factory flow charts that point to bad PCM's, and are often wrong.

FYI- There are many tests you can do on automobiles with meters (DVOM) that do not cost much. $20 or less at Walmart. A better choice would cost a little more at Sears. Just depends on how much you'd use it.

I've checked the coil wire ...it's ok,..so much for code 43. Is there something missing in the on board diagnstics that can't point to the problem of the rad fans coming on immediately after starting car.... and then starts the on-off cycle every 5 to 10 seconds ?????

Not the coil wire, the coil itself.

Very possible on the diagnostics, but typically they will turn on when the check engine light comes on to prevent overheating. While I can't say for certain, the running problem of the engine is what needs to be addressed first.

Hi again Doug,
I just got another trouble code added to list....
31 . It sonds as if this PCM is shorted or something in it is.

It may be a bad PCM, but check the coil first.

1995 Plymouth Neon Fuel System   

My problem is the fuel pump is not running. I tested the auto shutoff at the power distribution center, it said in the manual that there should not be voltage present at terminal 86 when the key is off. But there is. Can you tell me how to go about fixing this? And if this is why my fuelpump isn't running. Thanks, Tony

If you can wait until tomorow I can get a wiring diagram and answer your question.

ok thanks Tony

No problem, which engine does it have? 2.0 or 2.4

2.0 thanks

Looking at the schematic the auto-shutdown relay will not stop fuel pump from working. It will however stop spark and injector pulse. But you are correct. Pin 86 should only have power when the ignition is on.. Lets ignore the shutdown relay for now and test the fuel pump relay. Pin 30 should have constant power, and pin 85 ground. When the ignition is on or cranking pin 86 should have power. Then pin 87 will be the power supply to the fuel pump. Check these and we'll go from here. Be carefull that the relay's are not put in backwards. They will fit and work fine, but will fool you into checking the wrong wires.

Hi Chris,
Pin 30 does have constant power. Pin 86 does have power with key on. But pin 87 does not. What next?
Thanks
Tony

check for a ground on pin 85 both with key on and off.

pin 85 does not seem to ground,I want to make sure i did this right.I took a jumper wire in pin 85 hooked it to the tester light clip than put the other end to the positive on battery. I did test with key on and off. thanks Tony

You did it right. Try to jump pin 30 to pin 87 and try to start the car or at least check fuel pressure.

did not start,no fuel presure.Tony

You should next try to power up the fuel pump manually. Trace down the Dark Greeen/white wire at the pump. Check for power here while cranking. If there is none then use a jumper wire to power it up and listen for the humming noise. By jumping the pins like you did, the pump should have ran regardless of any other problems.

Have power at the pump. We tested the green and white wire. Since we had power back there, I had another pump I hooked up. When I turned the key it wouldn't work. So I went back and jumped 30 to 87 and with the key off the pump ran.
Thanks
Tony

So the pump now ran with the relay jumped, but only with the new pump?

Yes the new pump runs with jumping relay without the key on. But it will not run with the key and the relay in.

I think I understand. You never tried to run the pump in the tank only the new one. Or you did try and the pump didn't work? So our problem is still the computer will not command the relay to activate and turn the fuel pump on. We need to go back to the shut down relay and check the pins for powers and grounds. Pins 86 and 30 should have power all the time. Pin 85 should have ground with key on, and pin 87 should have power with key on and relay installed. You should also check for spark when cranking. If there is spark we can rule out the shut down relay and circuit as a problem.

It has spark and all the pins do what they should. The pump in the tank won't work. The second pump we have hooked up works when you jump it with the jumper.

Great, well our problem sounds like the pump in the tank needs to be replaced(obviously), but the problem remains with the relay. It is rare that multiple problems like this would exist. Did the car sit for a very long time, or was it involved in a collision? Either way we need to figure out why the ground is missing. Before you said the fuel pump relay had power on pin 86 only with the key on. Right? Did the power go away after 3-5 seconds? Also did you try disconecting the battery in hopes to reset the computer. You will need to replace the pump so we can test the rest of the computers outputs and see if the car will run.

My daughter drove the car Friday night without a problem she went to go somewhere Saturday morning and it wouldn't start. I will put the pump in tomorrow after work and let you know what happens from there.
I disconnected the battery for the night I will reconnect it tomorrow in case it needs to reset.
Thanks
Tony

I will also do some more checking on the relay circuit and other possible causes.

ok thanks

Hi Chris,
I went out and changed the pump and it started right up. I had the battery disconnected over night. Is there any chance that after a pump goes bad you have to reset the computer? Because I hooked this new pump up earlier and it would not work with the key.

I still think there is a problem with the computer because the car seems to have little gremlins. Like after it was running half of the dash did not work.
Thanks for your help.

If I should have problems in the future is there any way for me to request you for help?
Thanks again
Tony

I'm glad its running again, and I apologize it took so long to find the problem. There have been a few instances that I've ran into a problem with the computer not running a pump after it went out. For some reason the pump will pull too much power and the shut down relay kicks off. Then the computer needs to be reset.
As far as any future problems, You can request me by opening your question with a request:ie-"Question for Chris" at the top. Glad we got her fixed!!

Has the car been running good so far?

yes so far so good thanks Tony

Glad to hear it. If you don't mind would you hit the OK button and clear out the question. I'm trying to clear out some space. Thanks Tony.