QuestionQUESTION: Hi,
I have a 2001 Dodge Intrepid 2.7l v6. I've been having a problem with it, when it hits running temp. the RPM's start spiking and then backing off , it starts back-firing and the exhaust will get cherry red if run too long after it starts doing that. I cant figure out why it does this for the life of me but i did find some wires that are just hanging there. They are DG/RD and black. the wires are located on the passengers side by the head light. Any insight would be much appreciated!
Thanks,
Amber
ANSWER: Hi Amber,
I couldn't find any specific item that uses a dark green/red wire...are you certain it isn't dark green/orange? The black wire is a very common one as it is used to return current to the negative post of the battery, also known as 'ground' so those are found everywhere. See if you can move the wires around to find any nearby plugs/parts to which they might attach.
It sounds like the fuel/air mixture is going bad when the engine reaches operating temperature. The best way to get some hints is to read out the engine controller for fault codes which would tell us something that it has detected to be causing the problem. If you have an Autozone parts store near you they will do a free readout, and if not then an independent garage will likely do it for under $40. Find out any 4-digit fault codes and let me know specifically what they are and we'll go from there.
If may be that the catalytic converter's internal honeycomb has come loose and started to block the exhaust gas from getting to the tail pipe. But first see what kind of code you can find as a really off-value mixture of fuel and air do to an engine malfunction that a code will reveal. An exhaust shop can test for the possibility that the catalytic converter is blocking up, but go to an independent shop, not a nationwide franchise place, to have that test done.
Roland
PS: Please 'rate' my answer, and where you see the question about 'volunteer of the month' please consider answering 'yes' if this answer has been helpful. Thank you.
Roland
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QUESTION: I actually have one of those $150 scanners its coming up with P1391, and P0356 it was getting a P1494, and a P0354 as well but not in the last few times I've pulled the codes. it also has a bunch of little icons at the top the following are lit up: MIS, FUE, CCM, HTR, and EGR. And CAT, O2S, and EVA are flashing. i also have recently replaced both the crank and cam sensors. It runs about perfect until it hits running temp then it starts the revving and backing off and also recently it has died three times, once when i shifted it into gear, once when i stepped on the gas from a dead stop and once when i was turning a corner (I don't know if that helps at all but i figure the more info the better right?). As for the wires I'm sure it's red. I was just looking in a Chilton I found and it has a DG/RD wire going from the map sensor signal to the map sensor and also a DG/RD wire going from the Front wiper MUX switch signal to the wiper switch but since my wipers work fine I'm guessing its the MAP wire? and yea i was trying to do that earlier couldn't find where it went for the life of me. i guess if it goes into a plug the end got ripped off somewhere too so that doesn't help but do you think that all this could be caused by the MAP wire?
ANSWER: Hi Amber,
If the codes are fresh (e.g. you disconnected the battery for a few seconds to erase the codes, then drove it and found them 'new') we have to deal with only the current codes, probably.
The 1391 say that there is still an intermittent loss of the cam or crank sensor signal. When you installed the sensors, did you hold them against the surface (with the paper spacer in place) and then tighten the retaining screw? If not, get new paper spacers and re-install. Otherwise, it has to do with the wiring harness for one or the other sensor, probably.
The 0356 (and the 0354) are saying the the #6 (and #4) spark coil primary driver wires for the coil are not showing good dynamics. The noise suppression capacitor mounted on the cylinder head near those coil-on-plug units for 4 and 6 may be breaking down or not firmly grounded. (There is a separate supressor for the other cylinder bank, so that is why I suspect the local capacitor). Otherwise, check the harness wires for those units.
The 1494 is about the leak detection pump or its switch, but lets await for a return.
The symbols are probably; Miss (consistent with the 354,356), fuel mixture, ccm?, oxygen sensor heater circuit, exhaust gas recirc valve (possibly sticking ajar, so lubricate the stem, if there is one on the right manifold). Cat would be the converter function which may be what I mentioned in my first answer, 02s is oxygen sensor, eva is probably the evaporative emission pump issue (1394). Perhaps the manual will tell you what the ? item symbols mean.
I doubt the dark green/red is the MAP wire or you would have a code for that. It is mounted on the left intake manifold outside edge so you could check its harness just in case. That wire should be patent to pin 36 of the pcm, as a verification test. So if the continuity from the MAP plug to the pcm is OK then it is still an unknown.
It appears that you have enough to check out, so I will leave you with that.
Roland
PS: Thanks for the rating and nomination. Feel free to do it again, as each answer can be rated individually, with no limit!
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QUESTION: Yep the P1391 and P0365 are new. paper spacer? was that supposed to come with one? there wasnt one on the old ones. but im guessing thats not a major issue right now?
Well before i changed the cam sensor it was showing that 3 and 5 werent good and as soon as the new cam sensor was in it went to 4 and 6 so i kinda wonder if there is an underlying cause there.
It'd b nice if they had a list of what all the icons are but they dont lol but i gather that it means Comprehensive Component Monitors
Ill look into the EGR Valve and see about lubricating that.
Cat: right thats also kinda what my neighbor said but my dad said that it probably wasnt that because he thinks it should run crummy even when cold for what thats worth.
Wire: thats kind of what i was thinking too so ill look at the PCM tomorrow. but i was looking at the wires on the Map plugs on the intake manifold and they were DG/RD though.
Thank you for all of your help Roland! I'll get back to you soon.
AnswerHi Amber,
On the cam/crank sensor paper spacers, it may be the case that the 2.7L sensors don't need paper spacers to assure that the hall effect crystal doesn't get damaged by rubbing against the surface of the sprocket, so if the new ones didn't have spacers that would be the explanation. You can check with a dealer parts department on that detail. The 3.5L engine (and others) does use spacers on those sensors. The spacers, when used, can be purchased separately. Please let me know what you learn.
On the cat, it could be a operating-time blockage that doesn't occur until it warms up. But it may also be that it only shows overheating because of a very poor fuel/air mixture that occurs when the engine warms up. As I said, an exhaust shop can check that possibility out.
You are welcome. Feel free to 'rate/nominate' this answer as well. I appreciate that very much.
Roland
