In-depth look into p0300

[Jwithing]

Not sure if any of you found a fix but for me this is what worked.

Torque the intake manifold bolts using a torque wrench. I used 110 inch lbs in proper sequence. Also torqued my TB as well.

Problem solved for both p0300 and p219B.

Good luck.

Good advise. I know that's not my issue personally. Just threw on the 6.4 manifold a few thousand miles ago and torqued to spec in sequence.

 

[Jwithing]

Saw this stuff...

RVS Technology | Triboceramic Nanotechnology

Patented Triboceramic engine, transmission and power steering treatments. Improve the life, efficiency and smoothness of your mechanisms.

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Snakeoil? Normally I'd be leary of putting any sort of ceramics in the engine lol, but found the claims interesting. The number claims definitely seem a bit ridiculous though.

 

[Dusty]

Yeah Mister Luck, if it comes down to tearing it down I will be looking everything over, might even load all the springs to see the pressure rating on them to see if they all match up. An at that point lapping the valves at a minimum.

I’ve read through your messages and noted the things you’ve already looked at. I assume you’ve pulled the heads to replace the MDS solenoids, so I assume you replaced the head gaskets. The set condition for a P300 indicates a crankshaft differential between cylinders either based on RPM or engine load. A flashing MIL indicates severity. I'm not sure, but are there any other stored codes?

Things you may not have checked:

Engine oil system issue. Low or aerated oil, low oil pressure, incorrect or defective oil filter.

Low fuel pressure

Exhaust restriction.

Engine vacuum leak; intake restriction

Low compression

Internal EGR malfunction

Engine valvetrain or VCT issue (crankshaft position sensor)

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 03 June 2018. Now at: 063977 miles.

 

[MP9C]

I’ve read through your messages and noted the things you’ve already looked at. I assume you’ve pulled the heads to replace the MDS solenoids, so I assume you replaced the head gaskets. The set condition for a P300 indicates a crankshaft differential between cylinders either based on RPM or engine load. A flashing MIL indicates severity. I'm not sure, but are there any other stored codes?

Things you may not have checked:

Engine oil system issue. Low or aerated oil, low oil pressure, incorrect or defective oil filter.

Low fuel pressure

Exhaust restriction.

Engine vacuum leak; intake restriction

Low compression

Internal EGR malfunction

Engine valvetrain or VCT issue (crankshaft position sensor)

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 03 June 2018. Now at: 063977 miles.

Well,

You don’t have to pull the heads to change the MDS Solenoids.

It doesn’t have an EGR valve.

The crank position sensor has already been replaced.

The compression numbers are posted and even the lowest one as well above Chrysler spec and within the 20% rule of the highest.

If it had an intake restriction it would misfire all the time.

And if it had an exhaust restriction temps would be high in the catalyst and they’re not

I have done two oil changes on it and have use the same filter part number twice. So that would be interesting to find an alternative number for kicks.

I have went over all vacuum fittings and vacuum is sitting at 18

There are no other codes just P0300

Looking at the factory oil pressure gauge it is always right around the halfway mark or just over and that sensor is brand new as well because the old one was faulty.

 

[Dodge 1500 4X4]

I mentioned this before, please install a mechanical oil pressure gauge, remove the electrical sending unit and plumb the oil line from sending unit to gauge this will tell you what your oil pressure is at cold start/ running warmed up start, so you will know the condition of your bottom end.

 

[Dusty]

Well,

You don’t have to pull the heads to change the MDS Solenoids.

It doesn’t have an EGR valve.

The crank position sensor has already been replaced.

The compression numbers are posted and even the lowest one as well above Chrysler spec and within the 20% rule of the highest.

If it had an intake restriction it would misfire all the time.

And if it had an exhaust restriction temps would be high in the catalyst and they’re not

I have done two oil changes on it and have use the same filter part number twice. So that would be interesting to find an alternative number for kicks.

I have went over all vacuum fittings and vacuum is sitting at 18

There are no other codes just P0300

Looking at the factory oil pressure gauge it is always right around the halfway mark or just over and that sensor is brand new as well because the old one was faulty.

For some reason I thought you had removed the heads. According to the service manual, some have EGR, although it may not include a EGR valve.

Although the oil pressure gauge in the cluster may seem normal, the oil pressure sensor could be defective.

There could be a head gasket issue for the P0300. Is the engine consuming any coolant? Could warrant a system pressure test.

After re-reading some of your posts, I see you're close to 200K miles. Just based on experience I'm becoming suspicious the issue could be VCT (phaser) or timing chain wear.

Good luck.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 03 June 2018. Now at: 063998 miles.

 

[RedSRT4Me]

Well,

You don’t have to pull the heads to change the MDS Solenoids.

It doesn’t have an EGR valve.

The crank position sensor has already been replaced.

The compression numbers are posted and even the lowest one as well above Chrysler spec and within the 20% rule of the highest.

If it had an intake restriction it would misfire all the time.

And if it had an exhaust restriction temps would be high in the catalyst and they’re not

I have done two oil changes on it and have use the same filter part number twice. So that would be interesting to find an alternative number for kicks.

I have went over all vacuum fittings and vacuum is sitting at 18

There are no other codes just P0300

Looking at the factory oil pressure gauge it is always right around the halfway mark or just over and that sensor is brand new as well because the old one was faulty.

Not an intake restriction but just the opposite which is an imbalance of air between your runners. Retorquing the 10 bolts will probably fix your problem.

 

[MP9C]

Not an intake restriction but just the opposite which is an imbalance of air between your runners. Retorquing the 10 bolts will probably fix your problem.

I will give this a try, it can’t hurt

 

[MP9C]

For some reason I thought you had removed the heads. According to the service manual, some have EGR, although it may not include a EGR valve.

Although the oil pressure gauge in the cluster may seem normal, the oil pressure sensor could be defective.

There could be a head gasket issue for the P0300. Is the engine consuming any coolant? Could warrant a system pressure test.

After re-reading some of your posts, I see you're close to 200K miles. Just based on experience I'm becoming suspicious the issue could be VCT (phaser) or timing chain wear.

Good luck.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 03 June 2018. Now at: 063998 miles.

I will have to look around and see if I have a manual gauge chilling anywhere.

It’s not consuming any coolant

I have not done the timing nor had it apart or know the history so…. There are some possible questions here.

 

[greg mayrhofer]

MP9C , seems you have done some very extensive trouble shooting and work, not sure but have you reset the ECM, after all those major component changes, , i have the procedure, i got of this group some time back and have had to do it a few times and did reset the ECM to the base values. Would like to find out what your end results are after you have this PO300 code done

 

[Sherman Bird]

I agree but I’m going to go on a limb and say most guys don’t have a oscilloscope chilling in there garage. I was just pointing him in a couple directions of things to check to find out if his issue is load related or position related.

There are many inexpensive scopes out there (under 500 dollars U.S.) Given that the entire purpose of this and other forums is geared to DIY/save money, that is a very small investment. There are several forums that waveform libraries exist for reference, and for educating the layperson in the way to use a scope.

With modern vehicles, the need for advanced equipment has morphed into a necessity. The cost of throwing parts at problems on vehicles with enhanced OBD2 is astronomical, and seldom successful.

 

[MP9C]

Well I didn’t get into much today but I did go pick up a mopar oil filter and tossed it on and it is still missing but I would say it improved slightly since the oil pressure went a little higher with the new filter.

I still need to torque the intake manifold as suggested before and I am curious to hook up a oil pressure gauge as well.

I will update more as I move along.

But the dialogue has been great so far I appreciate the comments, feedback and ideas.

 

[jws123]

Hope you get it figured out had a annoying issue like this on a 2012 ram ab 2 yrs ago new cam ect ect could never find why it had a misfire at idle took it out on the parkway and floored the livin jesus outa it soon enough found the issue rod went threw the block

 

[Mister Luck]

Hope you get it figured out had a annoying issue like this on a 2012 ram ab 2 yrs ago new cam ect ect could never find why it had a misfire at idle took it out on the parkway and floored the livin jesus outa it soon enough found the issue rod went threw the block

That’s a good point and relevant to MP9C securing his intake manifold to prevent unmetered air from my adding to the fuel mix.

 

[MP9C]

Priming fuel pressure 55
Running fuel pressure 64

 

[dnj1967]

Cam and lifters need replaced. Sounds exactly how mine was. Ram is none for this

 

[MP9C]

Well in further testing, last night I cracked the PCM turned off the MDS and bumped the idle to what seems to be a reasonable rate to me 750 rpm and I went from 1500 misfires on a drive down to 50 misfires on the same drive. So that is interesting, I am going to do a longer drive and see what happens, I will try to data log it so I can do a good review.

 

[Jwithing]

Well in further testing, last night I cracked the PCM turned off the MDS and bumped the idle to what seems to be a reasonable rate to me 750 rpm and I went from 1500 misfires on a drive down to 50 misfires on the same drive. So that is interesting, I am going to do a longer drive and see what happens, I will try to data log it so I can do a good review.

I asked my tuner if I could pay him to review some data logs to see if they revealed anything. He told me I had a lifter issue. I reiterated that I popped the valve cover and checked valve travel and didn't think it was a lifter issue. No response. Not impressed. I'll be going with FRP in the future.

 

[Mister Luck]

My money is on valve springs, and in stating that
I’m going to probably need them myself.

 

[Jwithing]

I just got my blackstone oil analysis back. They said no excess metals in oil, so it's not cam/lifters.