P0305 code issue

[Durango]

Hello to all,

I have an 01' Durango 4.7 liter V-8 that had the "CEL" light came on and gave me a code of P0305. I took it in to the stealership and they told my the cylinder shows low compression and he said cause the computer to throw out the code. My question is has there been any service bulletins on this issue???? I don't race the engine at all in fact it's babied pretty much and only drive on the weekends. I have less than 85K on the odometer so what gives? This coming Saturday I'm having another opinion/mechanice give me another look at my engine but any imput you guys can give me is much appreciated.

Thank you for your help.

Durango

 

[Jim 5]

I would pull the plug out on that cylinder and see if you see any oil fouling the plug. If so, that will be a kind of verification of the low compression, and you'll know it's likely a piston ring issue and not a valve issue.

 

[Techniker]

Yep, you went right to the pirates. Did you actually see them check the compression on the cylinder or did they just say they did? A vehicle that new, and sounds like you have been responsible with it, should not have a low compression. You know why they told you that? Because they want to get you on an engine rebuild. No blue smoke or anything (which would be a bad oil ring, not a compression ring, but just want to make sure)?

A P0305 just means you have a cylinder misfire and while low compression can cause this, that would be extremely rare, ESPECIALLY with an isolated event like this. When you reset the light, has it come back on?

FAR more likely is bad fuel, a dirty fuel injector, or a spark plug that is about to go. This is what I would do: refuel your vehicle from a trusted gas station, pour a can of B12 Chemtool into the fuel tank (some people on here will recommend Techron Concentrate- I would agree, but you will need two bottles of it), and drive around. I think that you will never see this CEL again. If it does, replace the spark plugs first. I always err on the side of the cheapest repairs first before I go with the most expensive.

-Techniker

 

[Trav]

Did the dealer do an actual compression test with a gauge or just a load comparison with a scanner?
The compression would have to be very low for the ECM to trip a misfire code, the fuel mix will still ignite in a cylinder with low compression although it will not produce much force.

You need some actual numbers of the cylinders especially the one in question and the one's next to it to get a better idea of what's going on. Do a wet and dry test on the warm engine,throttle fully opened.

 

[Bill in Utah]

Okay lets get away from the Stealership

(how much did they quote for their "repair"?) and look at what a PO305 is;

Quote:

A P0305 code means that the the car's computer has detected that one of the engine's cylinders is not firing properly. In this case it's cylinder #5.
Symptoms
Symptoms may include:
the engine may be harder to start
the engine may stumble / stumble, and/or hesitate
other symptoms may also be present
Causes

A code P0305 may mean that one or more of the following has happened:
Faulty spark plug or wire
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector
Burned exhaust valve
Faulty catalytic converter(s)
Running out of fuel
Poor compression
Defective computer

So tell us how is it running? What were you doing when the code threw?

Reset the code and drive it. IF it throws it again lets go through the list before replacing the engine. (Just kidding about replacing the engine)

Bill

 

[Techniker]

Originally Posted By: Bill in Utah
IF it throws it again lets go through the list before replacing the engine. (Just kidding about replacing the engine)

Bill


That's exactly what the pirates want to do.

-Techniker

 

[Bill in Utah]

Originally Posted By: Techniker
Originally Posted By: Bill in Utah
IF it throws it again lets go through the list before replacing the engine. (Just kidding about replacing the engine)

Bill


That's exactly what the pirates want to do.

-Techniker


That is exactly what I said before editing. I did not want to get attacked... But I'm sure some would go there.

 

[Burt]

On my windstar I got this code and the cause was that most of the PCV intake ports were carboned up, so most of the recirculated gas was going to one cylinder. I had to take the upper half of the intake manifold off and then used $5 of carbuerator cleaner and a paper clip to open up the ports. Vehicle ran smoother and code went away. By the way, the independent shop wanted $500 to do this. It was kind of a fun job.

 

[Chris142]

If the compression was so low that it threw a code you would feel and hear the miss. I'd suspect a plug, wire, injector or coil if it had a coil on plug ign.

 

[Techniker]

Originally Posted By: Bill in Utah
Originally Posted By: Techniker
Originally Posted By: Bill in Utah
IF it throws it again lets go through the list before replacing the engine. (Just kidding about replacing the engine)

Bill


That's exactly what the pirates want to do.

-Techniker


That is exactly what I said before editing. I did not want to get attacked... But I'm sure some would go there.



I generally find that it's best to go for the full broadside rather than yield.

I have seriously considered applying as a technician at a dealership and walking around with an eye patch on and a bandanna on my head. Do you think I should have a parrot on one shoulder or would that be too much?

-Techniker

 

[Durango]

Hi you all,

First of all many thanks for your overwhelming replies! When I noticed the "CEL" light on the dash panel was at interection stopped at the red light so the engine was indling. I noticed nothing strange from the engine so since I was clost to home I returned to check it out. Again my Durango has only 85K on the odometer so I drive my truck on weekends only.

When I had the dealership do a dianostic all they told me was they did a compression test and they indicated it only had 30LBS! What the actual cylinder is suppose to be at with this type of engine I can't tell you. I have no idea what type of test they performed so perhaps it was with a computer and not an actual cylinder device.

Odd thing I noticed was that even myself I knowthat if it's low compression in the cylinder they actualy didn't say if the spark plug was fouled!!!! I did notice that when I drov off the dealership lot the engine was running fine and they reset the "CEL" for me. I then drove my truck for about 50 miles and everything appeard to be fantastic. I drove the truck home with the intent to take it out for dinner hour and then when it was started again the "CEL" reactived again after about 30 seconds.

Here's my reasoning..... If my no 5 cylinder was low on compression then WHY did th engine run so well when it was drove off the delalership lot??? I mean my engine ran silky smooth

I'm still thinking it maybe a sensor that tells my computer how to run the engine that may have gone south AND perhaps the sensor can't stand heat when it idleing or off throwing off too much heat. I now believ it can't be my "coil pack" cuz the engine was running so well off the lot.

I wonder too if my battery as it well into it's 4th year now. Or even maybe the TPS sensor may be messed-up?

Durango

 

[Chris142]

Originally Posted By: Durango




When I had the dealership do a dianostic all they told me was they did a compression test and they indicated it only had 30LBS! What the actual cylinder is suppose to be at with this type of engine I can't tell you.
Most stock engines have 120-160 PSI @ sea level. Anything less than 80 PSI won't fire at all.

 

[Bill in Utah]

Chris is correct. No way it has 30 lbs. So its running fine. Yuo just get the code. What I'd do is;

1. Swap plugs and (if possible) wires from another cyl. Clear the code and drive it.

If the code comes back then;

2. Not sure if it has coil packs for each cyl, if it does swap away. Clear code and drive.

If the code comes back from there and each time its the same code then going to spend more time trouble shooting it.

That engine in your vehicle is a EXCELLENT one and with only 85,000 ADULT operated miles no way the cyl has only 30 lbs. And if it did it you'd have other issues. If you snapped a ring or such the engine would be running different and other codes be happening.

Keep us updated on it!

bill

 

[CBR.worm]

If they did a compression test they probably either had a bad seal or did the test wrong (ie didn't open the throttle). If that one cylinder did actually have low compression it could be due to improper valve adjustment or a piece of carbon sitting on the valve seat keeping a valve from sealing. I would be more inclined to think it is a coil pack or plug.

It is possible that there is mechanical damage, but you should feel it if it is running on 7 cylinders.

Do you ever feel it stumble or miss? A scan tool should be able to get freeze-frame data that would record the operating parameters and other sensor data when the code occurred.

 

[Scott_Tucker]

I think the first thing you should have done is another compression test. If it really is low then you can have a leakdown test done to determine where the loss of compression is coming from. If the test shows that compression is equal across all cylinders then you can start diagnosing from there.

 

[The_Eric]

Originally Posted By: Bill in Utah
Chris is correct. No way it has 30 lbs. So its running fine. Yuo just get the code. What I'd do is;

1. Swap plugs and (if possible) wires from another cyl. Clear the code and drive it.

If the code comes back then;

2. Not sure if it has coil packs for each cyl, if it does swap away. Clear code and drive.

If the code comes back from there and each time its the same code then going to spend more time trouble shooting it.

That engine in your vehicle is a EXCELLENT one and with only 85,000 ADULT operated miles no way the cyl has only 30 lbs. And if it did it you'd have other issues. If you snapped a ring or such the engine would be running different and other codes be happening.

Keep us updated on it!

bill



While I agree with most of this, I will say that at 85k miles, he shouldn't waste time with switching plugs and wires. They're close enough to being due. Just replace them- as long as the O/P knows to replace them with O.E. plugs. Don't cheap out here.

 

[Durango]

Hello everyone,

I understand what you talking about and it makes sense but it's funny to me cuz after they told me the bad news they put everything back together and I drove away to think about.

What was funny was the the CEL light was off cuz they obviously reset the CEL light for me but the entire engine was running fine and VERY smooth so since I had some thing to handle so I ended driving about 50-75 miles street and freeway to get it done. During that time everything worked fine and no CEL light activation occured. When I got home and had a rest before heading out to dinner I started the engine and allow it to idle for about 30 seconds and LOL the CEL light reactived again and the engine started to run rough.

OBviously the coil packs and perhaps the TPS sensor worked before I drove it off the dealership lot. Right now it sits at home as I have another car to drive to owrk but my baby has had 85K pretty easy miles on the odometer and everything ran 100% since bought new and NOW all of a sudden my engine starts giving me a big headache. Spark plugs are always changed before a tune up is done by the dealership so these plugs are new since early this year. Even the possibility of a bad injector is ruled out.

Now I wonder if it's a sensor that's going/gone bad or I had thought it might be my gas cap. It's origional since bought new back in 01'

If it is my rings...then what am I talking about???? New pistons and rings??? then I may as well do a valve job too. It just kills me that I have to do this at the 85K mile and not sonewhere in the 150K down the road. That I can understand but no 85K.

Anyway I'm on another forum Dakota Durango.com and if you guys take a look see I'm not the only one having trouble with the no.5 cylinder. They have all the same symtoms as I do and can't find a solution. They're spending allot of money doing it themselves changing out possible parts and still no positive results.

Thanks again for your imput. Please keep them coming as I need all possible solutions before my next appointment with another mechanic. My worst fears are that my rings did go south in that no. 5 bank. :-( What a bad time forthis to happen to me during the two major holidays.

Durango

 

[Bill in Utah]

I'm about 90% sure its NOT your rings. Its something else that is NOT MAJOR. Why would I say that? Because if it was it would throw the light quicker than 50-75 miles.

I'd look at the wires, plugs and coil. Swapping them and if it throws a code on another cyl then atleast you know its not the #5 cyl.

There is no way you have only 30lbs compression. You'd feel it all the time the engine is running.

Bill

 

[Durango]

Bill,

Thank you for your fast reply.

Yeah that's what I was thinking after the dealerships dianosis and drove my Durango off the lot. I went and did all my home duties without a glimmer of the CEL light coming back on and that engine was so smooth I was about to cry.

They didn't tell me what the condition of the spark plugs were (wet,dry) I was only told my compression was 30lbs and that's what caused the condition. I don't know ifthey checked the coils, plugs or the TPS.

IF my compression was that bad then WHY did my engine run so well during my 50-75 miles of freeway/street driving. The engine went bad after I got home and rested before going out to dinner. That was in the garage NOT running for about 3 hours.

It's got to be something else! It must be something that sensitive to heat. Again I wonder if it's some type of sensor that went bad. When I get a chance I'll go to my nearest Chrysler and get a new gas cap and put it on. I don't want to rush into anything so for now I'll let the Culver Auto Clinic look at it.

Bill your a life save and a great pal for being there for me. I know you from other forums. Thank you much.

Durango

 

[Bill in Utah]

Gas cap is not a player here IMO. Does this have a coil for each cyl? If so, unplug and plug in only the number 5 when you get a chance. It throwing the code and running rough would have me looking first at connections, plug wire, plug then coil.

But if you can swap those out with other same length (I'd replace the plugs anyway) and the code does not return then it was the connections. If the code follows the part swap then its the parts. IF the code stays put then its something else but the parts that were swapped.

Contrary to popular belief here, I really do want to help folks.

Take care and good luck! Bill