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2004 Dodge Stratus 2.7L V6 limited to 2500 RPM
02-03-2017, 05:44 PM
Post: #1
2004 Dodge Stratus 2.7L V6 limited to 2500 RPM
I seem to be one of the few owners of the infamous Dodge 2.7L V6 engine that is relatively happy with it. It is in a 2004 Dodge Stratus SE (VIN 1B3EL36R64N243813) that I purchased new off the dealer lot. It presently has 205k miles on it and I have done most of the maintenance & repairs myself. I changed the oil every 5,000 miles using Mobile 1 full synthetic and a high-quality oil filter every time. I noticed the water pump leaking externally (luckily) in 2016 and I paid to have the timing chain, gear set, tensioner, water pump & oil pump changed. New spark plugs, PCV, air filter and fuel pump / filter were also installed. Also replaced rusty & leaky steel coolant lines at the time of the timing chain work. The engine has always performed well and run strong even with 205k miles on it. Amazingly, the transmission is original and still working well.

A few months after the work described above, the engine suddenly lost power while traveling at 75 MPH on I-75. My daughter was driving and was able to get safely off the expressway and park it. I picked it up with my tow dolly and since that day I have taken it to three (3) mechanics (Dodge Dealer Last) and have spent nearly $1,000.00 with no diagnosis for the problem. The engine runs fine until about 2500 RPM then it sputters, surges and generally malfunctions until the RPM drops below 2500 RPM and runs smooth again. I am amazed how quiet and smooth the engine runs at idle and below 2500 RPM with no clicks, rattles or misses.

The Dodge Dealership initially diagnosed (more of a guess) that the PCM, Crank Sensor & Cam Sensor were bad. They had no codes or real evidence that any these part were bad and admitted as much when I asked if the $1,800.00 they quoted would be guaranteed to fix the problem. They said no guarantee so I let them install new can & crank sensors. Still, the engine problem at 2500 RPM. After that the Dodge Dealer said they think the PCM is OK and that the problem is and internal engine issue and they would have to tear the engine apart to diagnose it. I declined.

I have had Great Success in maintaining my Jeep Liberty CRD for eleven (11) years with lots of help from forums such as this. I HOPE someone out there has a solution to this problem to share.
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02-03-2017, 11:40 PM (This post was last modified: 02-03-2017 11:52 PM by Rupe.)
Post: #2
RE: 2004 Dodge Stratus 2.7L V6 limited to 2500 RPM
This is a good sized can of worms to open so I'll throw you some ideas based on quirks I have seen over the years.

The dealer said they found no codes but I have seen many times where a fuel shortage does NOT set a code. Fuel pump or fuel filter might be to blame if they haven't been changed at normal intervals. Knowing the fuel pressure might come in handy here. (actual number, not "it's a good squirt")

Another problem that may not always set a code is a partially clogged cat converter. When I say "not always" it may need to be in that poor running mode for 10 - 20 seconds to be long enough to trip a code. A bad cat doesn't have it's own code so one must read between the lines for codes that indicate an issue for MAF or MAP or TPS being out of range. IOW, you've got your foot on the pedal going up a hill but the engine can't breath well enough to respond. Those codes get ignored for short spans but will set on a long hill climb. Yes, a bad cat can be intermittent!

That said, I have seen RPM limited by the ECM / PCM based on it not knowing if the transmission is in gear. (automatics in this case) IOW, a bad trany sensor that may not be picked up on a typical engine code reader.

Speaking of sensors, I had a Nissan that self-limited engine RPM if the speedometer acted up. In that case they used the speedo as the sensor for the ECM, and only on a standard shift, which for that model was very few vehicles. Basically there was nobody at the dealer who had experienced this issue but a bone yard speedo fixed the problem.

Now onto deeper thoughts... if there's a stray ignition signal going to the ECM (bum coil, ignition module?) it might go into a protective mode thinking the engine was running much higher than 2500 RPM. You might be able to catch that with a full function scan tool reading the RPM directly from the data plug, which shows exactly what the EMC sees.

That said, a full function scan tool might show something the average code reader can't show. Also, 2500 RPM seems to be an industry standard for limiting RPM when there's a sensor problem. OTOH, that's usually a sharp cut off point and it's got nothing to do with any rough running over that RPM, where a fuel or ignition issue *could* limit RPM and just be rough slightly above that point.

HINT: OEM fuel pumps generally crap out around 150K miles and filters tend to clog in the 30 - 50k range. A good set of plugs might go 100K but somewhere on the second set of plugs the coil(s) or ignition modules go south. (cap, rotor, wires, too) If you haven't done so I'd suggest serious consideration toward those basics BEFORE any tearing down of the engine. There's nothing mechanical that I can think of which will restrict the engine at 2500 RPM. If it runs well there it should run well at 3500 or 4500 too.

Keep us posted on your progress.

Edited to add: I'd also like to know if you can duplicate the issue at a given engine temp or say after so many minutes of run time. If you suspect a bad cat converter I can give you a few DIY tests that are not too costly, but are time consuming.
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02-04-2017, 05:55 PM (This post was last modified: 02-04-2017 06:30 PM by Steve 227.)
Post: #3
RE: 2004 Dodge Stratus 2.7L V6 limited to 2500 RPM
(02-03-2017 11:40 PM)Rupe Wrote:  This is a good sized can of worms to open so I'll throw you some ideas based on quirks I have seen over the years.

The dealer said they found no codes but I have seen many times where a fuel shortage does NOT set a code. Fuel pump or fuel filter might be to blame if they haven't been changed at normal intervals. Knowing the fuel pressure might come in handy here. (actual number, not "it's a good squirt")

Another problem that may not always set a code is a partially clogged cat converter. When I say "not always" it may need to be in that poor running mode for 10 - 20 seconds to be long enough to trip a code. A bad cat doesn't have it's own code so one must read between the lines for codes that indicate an issue for MAF or MAP or TPS being out of range. IOW, you've got your foot on the pedal going up a hill but the engine can't breath well enough to respond. Those codes get ignored for short spans but will set on a long hill climb. Yes, a bad cat can be intermittent!

That said, I have seen RPM limited by the ECM / PCM based on it not knowing if the transmission is in gear. (automatics in this case) IOW, a bad trany sensor that may not be picked up on a typical engine code reader.

Speaking of sensors, I had a Nissan that self-limited engine RPM if the speedometer acted up. In that case they used the speedo as the sensor for the ECM, and only on a standard shift, which for that model was very few vehicles. Basically there was nobody at the dealer who had experienced this issue but a bone yard speedo fixed the problem.

Now onto deeper thoughts... if there's a stray ignition signal going to the ECM (bum coil, ignition module?) it might go into a protective mode thinking the engine was running much higher than 2500 RPM. You might be able to catch that with a full function scan tool reading the RPM directly from the data plug, which shows exactly what the EMC sees.

That said, a full function scan tool might show something the average code reader can't show. Also, 2500 RPM seems to be an industry standard for limiting RPM when there's a sensor problem. OTOH, that's usually a sharp cut off point and it's got nothing to do with any rough running over that RPM, where a fuel or ignition issue *could* limit RPM and just be rough slightly above that point.

HINT: OEM fuel pumps generally crap out around 150K miles and filters tend to clog in the 30 - 50k range. A good set of plugs might go 100K but somewhere on the second set of plugs the coil(s) or ignition modules go south. (cap, rotor, wires, too) If you haven't done so I'd suggest serious consideration toward those basics BEFORE any tearing down of the engine. There's nothing mechanical that I can think of which will restrict the engine at 2500 RPM. If it runs well there it should run well at 3500 or 4500 too.

Keep us posted on your progress.

Edited to add: I'd also like to know if you can duplicate the issue at a given engine temp or say after so many minutes of run time. If you suspect a bad cat converter I can give you a few DIY tests that are not too costly, but are time consuming.

(02-03-2017 11:40 PM)Rupe Wrote:  This is a good sized can of worms to open so I'll throw you some ideas based on quirks I have seen over the years.

The dealer said they found no codes but I have seen many times where a fuel shortage does NOT set a code. Fuel pump or fuel filter might be to blame if they haven't been changed at normal intervals. Knowing the fuel pressure might come in handy here. (actual number, not "it's a good squirt")

Another problem that may not always set a code is a partially clogged cat converter. When I say "not always" it may need to be in that poor running mode for 10 - 20 seconds to be long enough to trip a code. A bad cat doesn't have it's own code so one must read between the lines for codes that indicate an issue for MAF or MAP or TPS being out of range. IOW, you've got your foot on the pedal going up a hill but the engine can't breath well enough to respond. Those codes get ignored for short spans but will set on a long hill climb. Yes, a bad cat can be intermittent!

That said, I have seen RPM limited by the ECM / PCM based on it not knowing if the transmission is in gear. (automatics in this case) IOW, a bad trany sensor that may not be picked up on a typical engine code reader.

Speaking of sensors, I had a Nissan that self-limited engine RPM if the speedometer acted up. In that case they used the speedo as the sensor for the ECM, and only on a standard shift, which for that model was very few vehicles. Basically there was nobody at the dealer who had experienced this issue but a bone yard speedo fixed the problem.

Now onto deeper thoughts... if there's a stray ignition signal going to the ECM (bum coil, ignition module?) it might go into a protective mode thinking the engine was running much higher than 2500 RPM. You might be able to catch that with a full function scan tool reading the RPM directly from the data plug, which shows exactly what the EMC sees.

That said, a full function scan tool might show something the average code reader can't show. Also, 2500 RPM seems to be an industry standard for limiting RPM when there's a sensor problem. OTOH, that's usually a sharp cut off point and it's got nothing to do with any rough running over that RPM, where a fuel or ignition issue *could* limit RPM and just be rough slightly above that point.

HINT: OEM fuel pumps generally crap out around 150K miles and filters tend to clog in the 30 - 50k range. A good set of plugs might go 100K but somewhere on the second set of plugs the coil(s) or ignition modules go south. (cap, rotor, wires, too) If you haven't done so I'd suggest serious consideration toward those basics BEFORE any tearing down of the engine. There's nothing mechanical that I can think of which will restrict the engine at 2500 RPM. If it runs well there it should run well at 3500 or 4500 too.

Keep us posted on your progress.

Edited to add: I'd also like to know if you can duplicate the issue at a given engine temp or say after so many minutes of run time. If you suspect a bad cat converter I can give you a few DIY tests that are not too costly, but are time consuming.

Rupe,

Thanks for the detailed reply. Do you think this problem could be caused by the timing chain being off a gear tooth? The dealership said the cam and crank sensors were in sync, but they also said I may need a new timing chain even though I told them I installed one summer 2016. I Have attached a PDF of the dealer invoice FYI.

I have experienced the intermittent catalytic converter failure with disastrous results on another vehicle. I will pay someone to check it out and at 205k miles it probably needs one. It seems that the very consistent problem at 2500 rpm (hot or cold engine) doesn't seem to be caused by the cat, but stranger things have happened!

I will buy a few new coil packs and swap them out with the cabinets old ones, plus Check all the wires.

One of my earlier guesses was the fuel pump so I had that replaced. It required dropping the tank and the filter was part of the pump assembly. Crazy design!

Thanks again!


Attached File(s)
.pdf  ec00e3b4d13d7667ae0602b92338effc_170202 2004 Dodge Stratus Service Complaint.pdf (Size: 162.6 KB / Downloads: 5)
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02-04-2017, 08:13 PM (This post was last modified: 02-04-2017 08:14 PM by Rupe.)
Post: #4
RE: 2004 Dodge Stratus 2.7L V6 limited to 2500 RPM
My first thought is if the timing chain was off a tooth or two, the cam / crank sensors would not line up so it would set a code. Keep in mind that dealer are always leery of aftermarket repairs, and your mention of the new chain might not have gotten to the technician.

Back to the ignition, coil packs, etc... you'd be better off spending that money with someone who knows how to use a scan tool reading live data. Again, that will show exactly what the EMC sees and possibly eliminate any ignition issues. It will also read all of the O2 sensors, which may be a clue to a cat problem.

As easy test (with the right tools) to do before reading further here is a fuel pressure test. Aftermarket pumps are famous for early failure(compared to OEM units) so it's certainly worth looking at, just because it's so common.

Now, the test I had in mind for the cat is a backpressure test. This works well for the "broken biscuit" that's internal and possibly restricting exhaust flow.... and once you buy the pieces you will have other uses for them in the future. We'll start off with a flex hose commonly used for a grease gun. (1/8" threads on each end) get a pressure gauge. For exhaust I use a 30 PSI version but you can use a 50 or 100 PSI, but it's easier to call a bum cat with the lower reading scale. Get some fittings to adapt the gauge to the hose. On the other end you need an old spark plug that you will break the insulator out of. A 14mm spark plug is the same thread as an O2 sensor. With this broken plug in hand get some fittings to adapt to the other end of that flex hose. This part will require some engineering so be prepared to tap a thread into the plug, solder, braze, or JB-Weld the fitting to the broken plug. (JB-Weld will take 650 degrees so no worries) In my case I also have a 90 degree fitting in case the work area is tight. Are you with me so far?

Remove one of the up-stream O2 sensors and screw in your adaptor. (missing sensor will set a code but not relevant to this test) Start the engine and note the pressure reading, which should be almost zero. Raise the engine speed and watch the reading. Anything over 5 PSI means a restriction. A clog that causes a performance issue will move the gauge up as RPM increases. I have seen in excess of 25 PSI with quick jabs of the throttle, which is why I start with at least a 30 PSI gauge. Again, you can use a 100 PSI gauge but it's harder to slice hairs and see 5 (or less) PSI on that scale. A good cat will be under 5 PSI through the entire RPM range and likely closer to 2-3 PSI.

Just a few pointers. Keep the flex hose away from hot / moving parts. (they are plastic / rubber) Work quickly to avoid that heat. If you need more length you can add another hose, they are cheap. You can do this test without driving the car and likely right in the driveway / garage provided you can access a front O2 sensor easily.

Oh, I mentioned other uses for this gauge rig. With a variety of fittings and gauges you can check oil pressure or auto-trans line pressure. Most of them are either 1/8" or 1/4" so add a bushing to your collection for the future. The grease gun hose will take 500 - 1000 PSI as long as you keep it away from hot parts.

Back on topic: Proper diagnosis is worth it's weight in gold. It will save you time and effort compared to trial & error parts replacement.
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02-05-2017, 01:07 PM
Post: #5
RE: 2004 Dodge Stratus 2.7L V6 limited to 2500 RPM
One more thing I would like to add to the diagnosis bag is a road test. Pre-plan this trip with the thought in mind that you may not be driving the van home. You may need someone on standby with the tow dolly. That said, find a road where you can "Break Down" safely. A less traveled road with wide berms. Take the van out and "Push It" hard. Get up over 2500 rpm and hold it there even if it starts to sputter. If you push it hard enough it should start setting codes that could save a lot of time, effort, and money. I would be sure that the computer was completely cleared before doing this. That way any codes would be new and relevant to this situation.

I am a big fan of letting all that fancy computer crap make my life easier when I can. It's there. Why not make it work for you if you can?

Keep us posted as to your progress.

Thanks for using the forum,
Garner

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02-06-2017, 07:01 AM
Post: #6
RE: 2004 Dodge Stratus 2.7L V6 limited to 2500 RPM
Ok, I'm commenting again because I had more time to go over your post in more detail. I opened the invoice you provided and looked at it and paid closer attention to the fact that it is a Stratus, not a van. That would be why your transmission has lasted to long. The 606 in a stratus is extremely well built. If you unhook the battery for any reason, have the computer "Quick Learned" with a full function scanner to increase the life of the transmission.

On the invoice I noticed that they stated, "Check engine light on, No codes relevant to the issue." I would like to know what codes they found. Sometimes those codes that don't "seem" relevant are very much relevant. Especially on a Stratus. They have a very complicated computer system where everything ties together. It may seem strange, but on that system a transmission sensor can cause engine issues. So I am still leaning heavily to taking it out and pushing it to the limit to get that Check Engine Light back on. Then have it scanned with a Full Function scanner. Record all of the code NUMBERS and post them here for review. Have the computer cleared after recording all the codes. Remember; as Rupe stated, a code reader isn't going to give you all of the codes if they are in the Transmission, ABS, and other higher systems.

Those codes could save another big bill like the one you posted? Good diagnosis can save throwing time, parts, and money at the problem until you accidently hit the target. Right now I'm leaning towards Rupes suggestion of fuel pump.

Please get back to us. We would love to hear the final Fix.

Thanks for using the forum,
Garner

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02-06-2017, 01:44 PM
Post: #7
RE: 2004 Dodge Stratus 2.7L V6 limited to 2500 RPM
(02-06-2017 07:01 AM)Garner Wrote:  Ok, I'm commenting again because I had more time to go over your post in more detail. I opened the invoice you provided and looked at it and paid closer attention to the fact that it is a Stratus, not a van. That would be why your transmission has lasted to long. The 606 in a stratus is extremely well built. If you unhook the battery for any reason, have the computer "Quick Learned" with a full function scanner to increase the life of the transmission.

On the invoice I noticed that they stated, "Check engine light on, No codes relevant to the issue." I would like to know what codes they found. Sometimes those codes that don't "seem" relevant are very much relevant. Especially on a Stratus. They have a very complicated computer system where everything ties together. It may seem strange, but on that system a transmission sensor can cause engine issues. So I am still leaning heavily to taking it out and pushing it to the limit to get that Check Engine Light back on. Then have it scanned with a Full Function scanner. Record all of the code NUMBERS and post them here for review. Have the computer cleared after recording all the codes. Remember; as Rupe stated, a code reader isn't going to give you all of the codes if they are in the Transmission, ABS, and other higher systems.

Those codes could save another big bill like the one you posted? Good diagnosis can save throwing time, parts, and money at the problem until you accidently hit the target. Right now I'm leaning towards Rupes suggestion of fuel pump.

Please get back to us. We would love to hear the final Fix.

Rupe & Garner,
Thanks for all your great suggestions. Now I have to get to work!
The dealership service advisor was not much help and I could not get the technician to talk to me. The service engine light was still on when I picked it up at the dealer.
After paying three times for analysis of the problem, it surely seems I will have to fix it with your help. Yesterday, I drove the car around town for 30 minutes and tried to go over 2500 RPM. The engine did more than sputter as it bucked and lurched violently every time I pushed it to 2500 RPM. Below 2500 it ran fine and the transmission downshifted when I hit the gas at a slow speed. I tried it in park and neutral and still it would not go over 2500 RPM. Took it to Autozone and had it scannned. See photo I attached. Disconnected battery to clear codes. Started engine and service engine light came back on almost immediately while in park.

Thanks again,

Steve


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02-06-2017, 06:21 PM
Post: #8
RE: 2004 Dodge Stratus 2.7L V6 limited to 2500 RPM
I don't have a lot of time right now to go over the invoice but I need to make 2 quick comments. First, disconnecting the battery won't clear the codes. That's most likely why the light is still on. Second, if you read my last post, the transmission now needs "Quick Learned." Any time the battery goes dead or is disconnected, the transmission should be Quick Learned. If not, it will default for many miles and high transmission wear occurs.

I'll try to comment more later when I have more time. Rupe will likely have many suggestions for you before then.

Thanks for using the forum,
Garner

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02-06-2017, 08:33 PM (This post was last modified: 02-06-2017 08:40 PM by Steve 227.)
Post: #9
RE: 2004 Dodge Stratus 2.7L V6 limited to 2500 RPM
The engine performance with the old factory original fuel pump (204k miles) was unchanged after the new fuel pump, so that seems unlikely to be the problem. However, I am willing to test the pressure to be sure. I did that test once before years ago on the fuel rail of a V-10 Ford E-350 van at 170k miles. Autozone loaned me the tool set for that and it was pretty easy.

A few weeks ago I filled the tank with premium fuel and a heavy dose of Sea Foam fuel treatment. That seems to have helped on other vehicles.

I don't own a scanner and I have frequently used the free scan service at Autozone and OReilly auto. I asked the guy yesterday if he could clear the codes and he said to disconnect the battery cable, as I have heard many times before. It seems to have cleared codes in the past on my other vehicles.

I posted a photo of the free scan from Autozone and it shows several codes including a transmission code and a fuel injector code. I'm sure the fuel injectors could be bad after 204k miles but I wonder if it makes sense that they work at low RPM but fail at medium RPM? It seems to say injector #2 is bad? Too bad the Chrysler dealer did not give me a detail report with all codes listed.

I'm pretty good with my tools and have been wrenching on my own cars since I got my first car in 1976. I presently own and maintain 5 vehicles for my family so I would not object to buying a good scanner. Any recommendations? I can't do all the work on our cars myself but I like to do what I can and reduce maintenance and repair costs when Possible.

Until now, my most difficult to maintain vehicle has been my 2006 Jeep Liberty CRD and even that is still running strong at 175k miles.

I have used interstate transmission in Troy, MI a few times in the past and I could have them check it? Last trans service they dropped the pan and changed filter and said the trans is in good shape for its age and miles. I've never heard of "Quick Learn" for a transmission after a dead battery but I am very interested. Maybe it is time to have the transmission checked thoroughly, but after I get my charging system fixed.

Next trip to Autozone I will have the battery and alternator checked. The battery seems weak but the car starts in about 3 seconds even with a weak battery.
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02-06-2017, 11:15 PM
Post: #10
RE: 2004 Dodge Stratus 2.7L V6 limited to 2500 RPM
Nicely detailed report you posted but not knowing when those codes were set keeps me from jumping to a conclusion. IOW, were they from on the road or as part of a diagnosis? It would be nice to have them cleared and get a fresh batch to work with.

So you say no change after the new pump, right? Still worth a double check but certainly changes the priorities for the moment.

A couple of Mopar quirks.... make SURE the charging system is ironed out before fooling with other stuff, and that includes poor grounds on older vehicles. If you are not sure then add a ground strap from the engine or trany to the frame and again to the negative battery. Another quirk is that "quick learn" Garner spoke of. Not sure exactly why, but Garner spent a few years in a trany shop and he's the expert there. All I know (after 45 years in the field) is it's a Mopar thing on all of their electronically controlled units. Basically I am trying to say get the electrical sorted out and DO NOT disconnect the battery once you get the trany re-learned. Of course this wont change the engine running issue, but it will help other things in the long run.

On disconnecting the battery to clear codes, that hasn't worked since OBDI systems of the mid 90s, although in some cases a prolonged disconnect (days or weeks) may clear them. Code clearing the proper way is via a scan tool. (and that wont upset the transmission) The scan tool your transmission shop has will likely clear codes and more, although they may or may not have someone qualified to diagnose your running issues. OTOH, if they will do you the favor and clear ALL codes, then read them again AFTER the light comes back on, we may have something to go on.

Oh, another quick pointer: This board seems to choke on attachments over 500 kb, so if you snap a shot of other code reports just keep the file size small like the last one. Hint: if you use a phone camera (typically 1.5 meg pics) run it through an edit and reduce to around 40% of original.
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