Caravan 3.3 not running right, misfire/rough idle...HELP!!
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Caravan 3.3 not running right, misfire/rough idle...HELP!!
My 3.3L Dodge Caravan has developed a misfire (code says that it's the 2nd cylinder). It's lower mileage, always well maintained, doesn't smoke, burn oil or anything like that.
I've done the following. Preformed a injector cleaning surface, changed plugs, wires, checked injectors w/stethoscope for "ticking"...all seem to be working, as I can hear them. It seems any advice I get is bad advice. There are no garages anywhere near me (and the ones in the next town are not trustworthy), and Im tight on funds. Some ppl say "I think your motor is bad" (which if this was the case, it would smoke), while others say it's likely something simple. I want to fix this one myself.
Any help would be appreciated. To show my gratitude, I would be willing to give the one who diagnoses it correctly a reward. I've been searching for "good advice" for some time. My grandfather was a 3.3, 3.8 genius, the master at identifying/fixing problems, rather than chasing them. Unfortunately he passed away recently, and takes his knowledge with him.
I've done the following. Preformed a injector cleaning surface, changed plugs, wires, checked injectors w/stethoscope for "ticking"...all seem to be working, as I can hear them. It seems any advice I get is bad advice. There are no garages anywhere near me (and the ones in the next town are not trustworthy), and Im tight on funds. Some ppl say "I think your motor is bad" (which if this was the case, it would smoke), while others say it's likely something simple. I want to fix this one myself.
Any help would be appreciated. To show my gratitude, I would be willing to give the one who diagnoses it correctly a reward. I've been searching for "good advice" for some time. My grandfather was a 3.3, 3.8 genius, the master at identifying/fixing problems, rather than chasing them. Unfortunately he passed away recently, and takes his knowledge with him.
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Hey this might seem like alot of work but I just did this a few days ago. Take the plenum off and check the wiring harness for the fuel injectors. I had two shops troubleshoot my 2001 Caraven se 3.3L and both were stumped. I had lots of codes that were coming up and the second garage wanted to replace my pcm for $1400.00. I was attempting to test the fuel injectors at the time and noticed a small wire split. Took off the tape and had 5-6 wires melted and touching. Bought a used one from the junkyard, replaced it and now my vans running better then ever. Also while you have the plenum off it would be a good time to buy 5-6 cans of intake cleaner and clean the air intake control valve along with the plenum. Even if your wires are fine this should help the idle. I'm not a mechanic, just a young guy who is feed up with never being able to find a trust worthy mechanic. So I read and try to do things myself. Hope this helps your problem.
Last edited by multimedia51; Jun 2, 2011 at 10:22 PM.
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The best answer for most questions asked here would be to have the vehicle diagnose by a properly trained technician but most users want suggestions, in that case its tough to properly diagnose something over the web..
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I had a nice long post about my experience with misfire and my thoughts on your problem.
But the site said I wasn't logged in and when I re-logged in, it lost my post.
Here's the short.
If the injector clicks normal as the others do, (I'd have swapped injectors with another cylinder to see if the problem follows) then I don't suspect injector issues.
I'd be looking at ignition.
The Camshaft position sensor and Crankshaft sensor play a huge roll in ignition timing.
Each is only about $40. I'd replace them just because.
Because the plug is wet, again I don't suspect fuel issues (again, I'd have swapped the plug and wire with another cylinder to see if the misfire moves with them), a new ignition coil is about $50.
There's also O2 sensor, air intake temp sensor, EGR valve, TPS, ect.
I'm pretty sure any of those would cause a random misfire and not single out #2.
Hope some of my reasoning helps out.
Let us know what you find,
PinCup
But the site said I wasn't logged in and when I re-logged in, it lost my post.
Here's the short.
If the injector clicks normal as the others do, (I'd have swapped injectors with another cylinder to see if the problem follows) then I don't suspect injector issues.
I'd be looking at ignition.
The Camshaft position sensor and Crankshaft sensor play a huge roll in ignition timing.
Each is only about $40. I'd replace them just because.
Because the plug is wet, again I don't suspect fuel issues (again, I'd have swapped the plug and wire with another cylinder to see if the misfire moves with them), a new ignition coil is about $50.
There's also O2 sensor, air intake temp sensor, EGR valve, TPS, ect.
I'm pretty sure any of those would cause a random misfire and not single out #2.
Hope some of my reasoning helps out.
Let us know what you find,
PinCup
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It was a faulty coil
Very true. Unfortunately my area Chrysler dealer missed the mark, hence why I came here looking for a 2nd opinion. They first told me the engine was old, and likely on its way out (I laughed at that). They performed a compression test, then saw that there wasn't any issues. They suggested that the problem was likely my computer. I mentioned the coil, and they told me that it almost never is the coil, and that I shouldn't waste my $100, because if the coil doesn't fix it, it's non-returnable (electronic parts have no-refund). The parts guy said that in the last 6 or 7 years, they've sold roughly 6 coils in total....so in their eyes, this added validity to their argument. On a side note: Although wires in the harnesses leading into the computer do on rare occasions become loose etc, a cylinder would either get full spark, or none at all. A faulty PCM wouldn't cause weak spark. Spark was visible in the #2 plug, it just wasn't strong.
I paid the diagnostic fee, but was told little more than what a basic key-dance did.
Very true. Unfortunately my area Chrysler dealer missed the mark, hence why I came here looking for a 2nd opinion. They first told me the engine was old, and likely on its way out (I laughed at that). They performed a compression test, then saw that there wasn't any issues. They suggested that the problem was likely my computer. I mentioned the coil, and they told me that it almost never is the coil, and that I shouldn't waste my $100, because if the coil doesn't fix it, it's non-returnable (electronic parts have no-refund). The parts guy said that in the last 6 or 7 years, they've sold roughly 6 coils in total....so in their eyes, this added validity to their argument. On a side note: Although wires in the harnesses leading into the computer do on rare occasions become loose etc, a cylinder would either get full spark, or none at all. A faulty PCM wouldn't cause weak spark. Spark was visible in the #2 plug, it just wasn't strong.
I paid the diagnostic fee, but was told little more than what a basic key-dance did.
well, a lot of shops has Old school "sun scope" that can test Coils strength. Or you can use the cheap spark Gap tester.
Fuel injector wise, we can use a meter to measure resistance, or do a Injector Flow balance test with a Pulse tester.
Compression wise, we have compression gauge, or more sophistcated pressure transducer.
Computer? it usually throws a code, or if the quad driver is dead, you get no spark/injector pulse, easily tested with test lights.
If it has a DEAD mis-fire, it is very easy to identify.
Only time when I have problem diagnosing Mis-fire code is when it occurs "once in a great while when the customer sitting on the red light".
I agree with the statement u posted b4. Cars got a lot more sofisticated and well built, But Service became ridiculously expensive, parts and Labor. Only thing keeping us mechanics in business is Cars are also ridiculously expensive. When did a Mini Van goes for $30k+?
of course, premium Extended Waranty is always an option! tho, they usually end up costing more than the repairs.
trusting the parts counter guy to diagnose ur vehicle is a Big mistake. Guess how much money Autozone made from their "free CEL scanning" from selling parts ppl doesnt need.
Do you go to a pharmacist first or a doctor when u r sick?
At where I work at, almost everything is returnable until the car is fixed. We have a lot of Customer simply Refuse to pay because the car if not fixed after we performed a suggested repair. Customer doesn't want an engine, they want to pay their initial quote, and fix their car.
If we drop an engine in, and the car is not fixed, either the engine is coming back out for free, or anything we do after the engine will be free.
in return, our shop almost have no slow season, even when every shop or dealership in the neighborhood are dead, us and a Ford Dealership 2 blocks away are always pack. And even if we are a chrysler dealership, we constantly getting other make and model comes in for service.
Last edited by steak59; Jul 5, 2011 at 04:16 PM.
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thanks for the reply! Finding "good" advice is hard, it seems the everyone chases problems, rather than identifying them. It turned out to be the coil. A good Dodge technician diagnosed it. Because it had both a #2 missfire, and a random cylinder missfire code, he knew it was the coil (those coils send pulses out in pairs, hence why I had 2 codes). After replacing plugs @ $40, wires @ $60, a compression test @ $50+ (my 2nd in less than 2 mthns), and $150 for a fuel injector cleaning service. It was just a $99 coil.
To loosely quote a candid conversation with this veteran Dodge tech: "Checking plugs is always a good idea, and replacing wires not a bad one either, but rarely is a wire the problem...wires will last 20+yrs. Your van wasn't smoking and had tell-tail codes, so anyone saying that you may have compression issues, or that a dirty injector would suddenly cause such a drastic change, is not applying any of their experience. Unfortunately, they get lost without the book. Nothing more than racking up billable hours, replacing things that may or may not make the problem go away. I think that's why we're now called "technicians", not mechanics (laughs). When I was younger, the small shop I worked for would've been ran out of town for replacing parts a customer didn't absolutely need. Now a days, that's how the industry works. Even if a customer can't afford it and just wants to get down the road, they still won't think outside the book. Why? Because we're Chrysler, we're not here to give you a break. They don't do quick fixes or patches. If it's worn, it gets replaced, without compromise. Is it right? is it wrong? well I understand both sides, but all I can tell you, is it's expensive"
I know some techs will disagree with that candid statement, but others might see some truth. I, personally, have worked for Chry Co, and will admit.....this old guy speaks the truth. I understand that they are a corporation, that want to do what they can to maintain the integrity and engineering that goes into their cars (ie: no muffler tape lol). But with that said, the Customer care line gets, on average, 120 formal dealer-related complaints for every 7 business hours, every day. They don't write articles/advice columns about how wonderful and trustworthy dealers are
. Some might not agree, but the #1 complaint I got from my customers was service. They love the cars, just hate what the service industry has become.
I digress. Thank you for your help guys.
To loosely quote a candid conversation with this veteran Dodge tech: "Checking plugs is always a good idea, and replacing wires not a bad one either, but rarely is a wire the problem...wires will last 20+yrs. Your van wasn't smoking and had tell-tail codes, so anyone saying that you may have compression issues, or that a dirty injector would suddenly cause such a drastic change, is not applying any of their experience. Unfortunately, they get lost without the book. Nothing more than racking up billable hours, replacing things that may or may not make the problem go away. I think that's why we're now called "technicians", not mechanics (laughs). When I was younger, the small shop I worked for would've been ran out of town for replacing parts a customer didn't absolutely need. Now a days, that's how the industry works. Even if a customer can't afford it and just wants to get down the road, they still won't think outside the book. Why? Because we're Chrysler, we're not here to give you a break. They don't do quick fixes or patches. If it's worn, it gets replaced, without compromise. Is it right? is it wrong? well I understand both sides, but all I can tell you, is it's expensive"
I know some techs will disagree with that candid statement, but others might see some truth. I, personally, have worked for Chry Co, and will admit.....this old guy speaks the truth. I understand that they are a corporation, that want to do what they can to maintain the integrity and engineering that goes into their cars (ie: no muffler tape lol). But with that said, the Customer care line gets, on average, 120 formal dealer-related complaints for every 7 business hours, every day. They don't write articles/advice columns about how wonderful and trustworthy dealers are
. Some might not agree, but the #1 complaint I got from my customers was service. They love the cars, just hate what the service industry has become. I digress. Thank you for your help guys.
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hahah, maybe. In this case, the van was low mileage. Obviously if they looked off, or the casing melted, that would raise suspicions, but my 77 Dodge truck still wears its original factory wires. As long as they aren't cracking, and are not rubbing against each other, they'll be fine
Last edited by Jon Mopar; Jul 8, 2011 at 10:50 AM.