Hey Guys,

I have an 05 Chrysler Town and country with 216K miles. I need some help diagnosing a drivability issue. Here is the background:

Van has intermittently thrown code P0305 for a misfire for the last few years.

Coil, plugs and wires changed 18 mos ago. Engine light would randomly come on and go off. Usually with a P0305 code.

Has been running fine for the last 6 mos. No light, no codes.

A couple of days ago my daughter drove it to work. On the way home, it shuddered and she said make a crunching sound. She said she also smelled something like rubber burning. She said it would not go over 2500 rpm and she limped it home at 30 mph. Engine light came on.

When I start it up now, it does run rough, but spins up to 4000 rpm. I drove it and it shudders at take off but smoothes out some. I was able to get it up to 55 mph. It does seem to struggle more to get there than it did previously. Transmission fluid isn't burnt and it shifts fine.

I ran the codes and it has another P0305 code. I was thinking based on her description of the crunching sound that maybe the catalytic converter had failed and the material inside was clogging the exhaust causing the rough idle and acceleration, but it isn't throwing any exhaust codes. I'm thinking the P0305 is probably a bad injector, but the crunching sound indicates something else is going on to me.

So, what do you guys think?

Thx!
Randy

Well, you didn't say what engine is in it but crunching noises almost always indicate a catastrophic failure of some sort no matter the engine.

3.8 v6. Yes, I agree, however, I have driven it several miles now with no issues other than shuddering at takeoff and running rough.

Common stuff I see on them is externally cracked porcelain on spark plug, bad plug wire, bad coil pack (weak or no fire on one of the 3 banks) and no coil driver pulse from PCM. If all that checks good then a compression test is in order.

I had a 03 that the injector harness had melted where it plugs in under the coil pack took a while to find it people work on the engine can push it to close to the head and it melts .

If you replaced with the factory Champion Double Platinum spark plugs, the little welded om platinum alloy discs that make the two ends of the spark gap come off. It takes a magnifying glass to see them.

Some of my mother's 3.3 L second replacement plugs discs came off in only about a year.

I replaced them all with NGK Irridium plugs and so far no failures.
The engine accelerates noticeably smoother.

There is a TSB for 2005 for the 3 "wasted spark" coil packs failing.

EGR valve is all electric and has also failed.
If it fails partially open the engine runs rough.

In your 216,000 miles have you had any AC system freon leaks?
If so, where?

Thanks for the info. I replaced most of the a/c components with a lifetime warrantied a/c kit last summer. This summer it developed a leak somewhere and quit blowing cold. I have not fixed it yet. Depending on what shakes out with this most recent issue, I may not fix it, just sell it cheap. The wife is due for a new car anyway.

What your describing is going to be extremely tough to fix without actually hearing it. Ok, that said.

Our 2005 T+C has a scrunching noise. And has for some time. Needs upper strut mounts I just haven't taken the time to fix yet.


If your suspecting torque conv / trans issues, drop the pan for a look see. Pull the filter and open it up ( Do NOT use a wizz wheel to to it ) Ck for heavy particles in the fiber.( it looks like heavy black sand ) If there, Plan on dropping it and replace the torque conv soon

But what your describing sure sounds like coil pack or plug wire failure.

You're dealing with a single cylinder misfire. The shudder you're experiencing on take-off and rough running sounds like ignition misfire. You know it's cylinder #5 so start swapping ignition components with a known good cylinder. Clear codes...when the symptom/problem recurs see where the code is. If it's still #5 think mechanical,if it moves to the cylinder you moved components to....you have found the problem. Good luck!

I suggest you buy a NGK LZTR5AIX-13 spark plug ( Stock number 2314)
and swap it into number 5 cylinder.

Inspect the OEM Champion RE14PLP5 spark plug carefully that came out of #5 cylinder.
Use a magnifying glass to see if both tiny discs are still welded in place. A bigger gap than spec is a clue that one or both discs are gone.

I use a trusty old hand cranked Biddle Megger Tester set on 1000 volts to test the internal resistor of the Champion "RE" plugs which have an unusual patented semiconductor element inside.

https://www.ebay.com/itm/Biddle-Major-Megger-Tester-21159-W-Case/282747408077?epid=686950419&hash=item41d50f0ecd:g:wQ4AAOSwaEhZI9tT

But that might be overkill.

Some experts have doubts about Champion's choice of internal resistor

http://www.vansairforce.com/community/showthread.php?t=90844

While you have the #5 ignition wire off,
check resistance from wire end terminal to terminal and compute ohms per foot.
Wrap a strip of aluminum foil around the outer insulation of the ignition wire and measure megaohms of resistance between aluminum foil to inner carbon fiber conductor to see if that wire has a leak to ground.

Put wire and plug back.
Fire up engine.
Test drive to see if roughness gone.
Use stethoscope or long screwdriver to hold against #5 fuel injector and listen to see if its clicking noises are similar to other injectors.

Might not be a bad idea to look at the ignition wires in a very dark place to see if you can spot any light from corona discharge: that blue green glow.

Thanks fellas !