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Discussion Starter · #1 · (Edited)
I'm at wits end and really need some help here.
2005 300C 5.7 89,000 miles
Ran fine and then one day would crank but not start. Wouldn't even catch. Starts briefly on starting fluid and dies immediately. NO Codes.
After a bunch of new parts it starts with Starting Fluid but runs like it was running on 3 cylinders.
Needs a bit of pedal to stay running (like crap) If you let off the accelerator the RPMs will drop below 700 and it will stall.
Now it has a Bank 2 Lean Code.

Replaced main fuel pump. Checked: Fuel pressure. Gauged good while cranking and running.
Replaced all the Plugs.
Replaced coils. Checked and spark present on all plugs.
Replaced Crank and Cam sensors.
Replaced MAP sensor.
Engine temp sensor reads correctly (Using Dash diagnostic display)
Pedal Position sensor reads correctly.

Condition of NEW Spark plug ceramic electrode after running motor for a few minutes.
Plug 1: Really clean
Plug 2: Really clean
Plug 3: Really clean
Plug 4: Really clean
plug 5: Clean on one side. Pretty clean on other with light oil spot.
Plug 6: Heavy black soot
Plug 7: Clean on one side. Mild soot with oil spot on other side.
Plug 8: Mild/Medium soot

I need some pro advice at this point.
 

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Discussion Starter · #6 · (Edited)
What does it sound like when it's cranking?
Have you done a compression test?
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It sounds relatively normal while cranking. I've been topping the new battery up every day so its strong.
I did not hear any compression on valve train related sounds during cranking but I will check again tonight.
I did a compression test on an few cylinders but not all. Those were ok.
Ill do them all tonight.

I will get the exact Bank2 Lean code tonight as well.
 

· LX Padiwan
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Yes, it could be injector(s), upstream O2 Sensor(s) and/or exhaust leak issues, etc. A real good quality computerized diagnostic scanner (you could easily get one for what you paid for all the parts you probably didn't need.....mainly fuel pump, coils, cam/crank sensors) will allow you to view live and freeze frame data on injector duty cycles and almost everything you'd probably need to know to troubleshoot this problem properly. This will tell you if one or more injectors are a problem, O2 Sensor(s) is/are bad, cam/crank sensor synchronization and so on. What brand, type and heat range spark plugs did you install? What were the gaps? What did the ones you took out look like.....gap, color, etc? Did you synchronize the new cam/crank sensors? Are you using a good top tier fuel or some cheapo brand? What did the end of the MAP Sensor look like...the end that protrudes into the intake manifold? This is probably not related, but did you check the back side of the throttle body butterfly and the intake manifold plenum? If it looks like most.....backside of butterly gunked up, oil in the plenum, and the MAP Sensor tip oily, then changing that was probably something that needed changing. If yours looked like I described, you should probably consider installing a good catch can to mitigate most of the contamination.

Good luck and please keep us posted on your findings and progress.
 
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typically one plug being sooty over the rest indicates a problem in that cylinder. Also with spark, I would guess its probably not PCM related though it could be. My guess is fuel. Either not enough fuel pressure or you got a slug of poor fuel with water contamination etc. The fuel rail has a valve on it, with a rag after having cycled the key a couple times, check to see if any fuel pressure squirts out. If it has good pressure, its probably not fuel pump or pressure related. If you suspect an oxygen sensor is bad, typically that only will show itself a few minutes after start. Those sensors are not looked at on start up as their readings are not correct until after warm up. Also it will not go into open loop operation using oxygen sensors for mixture control until a certain coolant temperature is reached. This sounds very much like fuel starvation from a bad pump or relay etc.

For the record, a bad fuel pump is how I got my 04 Ram really cheap :rock:...quite common on vehicles of that age.
 

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The plug condition on a few cylinders indicates problems with those specific cylinders. Could be injector, spark, etc. but I would compression test as others have suggested. Older Hemis can have several issues that will cause what you describe - including broken valve springs. They break in such a way that a lot of times it does not drop a valve, it just does not hold the valve closed anymore so you have no compression in that cylinder. You can then replace the springs with engine in the car it is not too difficult/expensive I have done several. They can also wipe cam lobes and/or lifters. They can also drop valve seats though that typically happens after you overheat one... Your symptoms really sound to me like you have a dead cylinder or two...
 

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Discussion Starter · #12 · (Edited)
Thank You.
Fuel pressure is good. I have a pressure gauge connected inline with the rail. Fuel is fresh. 2 weeks old. 3/4 tank.
I lost the record of the previous code. No codes now.
Did a very dry compression check and results are as follows:
1-160
2-140
3-155
4-130
5-150
6-80
7-160
8-155
Cylinders 2-4-6-8 are adjacent to on another on the passengers side bank.
Something is obviously wrong with #6.
What doesnt make sense to me is how bad the engine ran.
Even completely down one cylinder, the engine would have started and ran "ok" but mildly rough.
My engine barely ran, ran like complete sh*t, and felt like it was on 5-6 cylinders and not 7.
Maybe there is a mechanical failure somewhere that is affecting the overall engine timing. I'm starting to feel dumb.
Is there a high end [email protected] scanner under $600 that you guys recommend ?
 

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Thank You.
Fuel pressure is good. I have a pressure gauge connected inline with the rail. Fuel is fresh. 2 weeks old. 3/4 tank.
I lost the record of the previous code. No codes now.
Did a very dry compression check and results are as follows:
1-160
2-140
3-155
4-130
5-150
6-80
7-160
8-155
Cylinders 2-4-6-8 are adjacent to on another on the passengers side bank.
Something is obviously wrong with #6.
What doesnt make sense to me is how bad the engine ran.
Even completely down one cylinder, the engine would have started and ran "ok" but mildly rough.
My engine barely ran, ran like complete sh*t, and felt like it was on 5-6 cylinders and not 7.
Maybe there is a mechanical failure somewhere that is affecting the overall engine timing. I'm starting to feel dumb.
Is there a high end [email protected] scanner under $600 that you guys recommend ?
I agree completely. even on 6 cylinders it should start and run. A mechanical failure on just one cylinder would not keep the engine from starting or even idling. If the timing was to jump, I would expect a check engine code since there would be a mismatch of cam and crank timing...but I could be wrong. I would start with fuel pressure and pulling that valve cover to inspect #6.
 

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I would try another pcm. The compression test really isn't conclusive to the issue that your having. #6 is lower then the rest which is obvious but that's not your problem if it's running on less cylinders.Best results with compression tests and leak down tests should be done with a motor that has been running. What you might want to do is take off the valve cover and took to see if you haven't dropped or bent a valve.
 

· 2005rtmag
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A leakdown test could tell you where the compression is leaking, intake valve, exhaust valve, or past the rings into the engine pan. But, at this point, I think I would pull the valve cover and see if I could see what the issue is with cyl 6. Or first, use a borescope to insert into the spark plug holes first to see if you can see anything wrong.
 

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It will typically run really bad and even not start with one bad cylinder or one broken spring. Not only is the one cylinder dead, but it is pumping unburnt fuel and air out the exhaust messing with the O2 sensor readings on that bank... It only takes like 15-30 minutes to pull the valve cover on that side and if it is a broken spring you will see it. If you turn it over by hand with a socket and watch the rockers on that cylinder, you will see if you have a lobe or lifter wiped out.
 

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Discussion Starter · #20 ·
The engine was never overheated. Piston tops have no physical damage (as far as I can see through the plug holes) I took the valve cover off and the springs look fine. I dont see anything that would indicate a broken spring.
I'll have someone turn the engine over while Im watching the rockers this weekend.
 
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