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Chrysler Repair/engine idles erratic, code 0340


QUESTION: I recently replaced the head gasket on my 2001 Pt Cruiser 2.4 ltr. I was very careful to ensure that my timing mark on the crank shaft lined up with the mark on the oil pump and both cam shaft pulleys were perfectly aligned, at first I had no spark and found out I had the plug for coil pack and cps switched. Now it runs great at acceleration but has rough idle. Check engine light on.

ANSWER: Hi Michael,
Try for a fault code readout using the ignition switch: "on-off-on-off-on and leave on" doing that in five seconds or less elapsed time. Then watch the odometer window to see the mileage reading be replaced by a four digit number(s). Tell me what you find and we'll go from there.
Please read the PS below and respond to it.

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QUESTION: P1684, P0340

ANSWER: Hi Michael,
The 1684 just means the battery was disconnected some time in the recent past, which is true.
The 0340 means there is an issue with the camshaft position sensor signal, but that may have occurred when you had the plugs switched.
So try disconnecting the battery for a minute to erase the codes, then reconnect and start the engine and run it for a few minutes. Then read the codes again (the 1684 will be there, of course). If the 0340 continues then check the camshaft sensor wires. You can also measure the voltage pulsation between the signal wire (tan/yellow) and ground wire (light blue/black) while you turn the engine over by hand (socket and handle on the crank pulley bolt). You can probe the wires with small pins, and of course the ignition switch must be in the 'run' position. It should vary between 0.3 and 5.0V many times per revolution if it is working properly.
If the 0340 doesn't continue then I would check out the egr valve to see if its stem might be stuck ajar. If that is the case then spray some WD-40 on the stem where it enters the valve body and move it back and forth to free-up the action of the valve using the tip of a screwdriver in the slot that circumscribes the stem as the lever point.
Let me know how this works out.
Please read the PS below and respond to it.

---------- FOLLOW-UP ----------

QUESTION: Well I have a hole different issue. After I had done what you said it ran fine, but I ended up removing the head again as the head gasket was still leaking (warped head) But after having the head machined and reinstalled, it again doesn't want to start. I have fuel and spark. It tries to start but fires against the starter like its out of time. I followed the same procedures as before on the removal of camshafts and components and laid the out on a table in sequence and marked. Timing mark on crank shaft aligned as well as camshaft sprockets. Head was off for about a week before reassembly. I checked all timing 3 times before I put the covers on. I even went back and removed them to ensure it didn't jump time after it kicked against the starter and everything was still dead on. When I try to start the rpm gauge goes crazy and tries to start but kicks hard against the starter like its severely out of time. Is it possible that since the lifters were out of the engine for so long that the oil may have drained as a result the valves aren't opening and closing properly?

Hi Michael,
Yes, it is possible the lifters are not filled with oil. There is a page in the shop manual about this sort of problem which I can copy and attach to an email. To do that I need to know your email address which I don't see routinely. So send me a new question, click on the box to make it private, and the when you list that address don't use @, instead us "at" or it might be automatically erased.
Also, check for fault codes as you have done before and let me know of any.
Please read the PS below and respond to it.

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Roland Finston


Free fast answer to your repair question about a Chrysler/Dodge/Plymouth car, minivan, SUV, or truck. Problems with electronically controlled engines and transmissions as well as body wiring problems are my specialty. This free troubleshoot advice forum helps you diagnose faults, minimize repair costs or do-it-yourself.

I answer questions seven days a week and respond to you in about 30 minutes. "Maxed Out" means I am answering another question, briefly unavailable, or asleep overnight, so try again later.

I have do-it-yourself experience (50+ years) and a library of 100 1982-2011 Chrysler factory shop manuals and 20 multi-manual Chrysler Corp. CD's.

I was voted "Top Expert" 2010-2015, here at AllExperts, and have answered 20,000+ questions.


Five decades as a 'do-it-yourselfer' on domestic and imported cars.

Yahoo Autos Group called The Chrysler Lebaron Club (co-moderator)

Advanced degrees in Physics/bruised knuckles

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"Top expert" of 2010, 2011, 2012, 2013, 2014 and 2015 here at Allexperts. Quickest "average response time" at Allexperts (currently no. 1).

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