Runs rough

Just need to clarify the issue a little.

You are replacing the spark plugs and then after you drive for a short time, they are fouled again?

If this is the case then we have too much fuel on that bank or it is just unburned fuel. So I would suggest starting with compression check and go from there unless that is what you did when you say a cylinder drop test.

https://www.2carpros.com/articles/how-to-test-engine-compression

If this is the case and you have 135 on all 3 then that is the issue. That is too low as it should be at least 170 on this engine.

If that is the case then we need to do a cylinder leakage test to find out where we are losing compression but I am thinking we have a cam issue.

Let us know and we can go from there.

No not driving a little they fall out right away just revving it up a couple times in the driveway. I thought about doing a compression test all I did was with the engine running disconnect the power to each coil and listen for an RPM change. I replaced the AIT sensor as that was one of the codes and I tested the sensor plug and it was good and I tested the sensor and it seemed to have faulty readings.

I put in the cleaned up spark plugs and the new AIT sensor and it fired right up and idled at 1000. Then I did the cylinder drop down test where I disconnect the power to each coil individually and listen for an RPM change. Cylinders one three and five reacted. Cylinders two four and six had no change in RPM when power was disconnected to the coil indicating that they are not firing. I will include the codes that came up. P2305, p2311, p2317, po300 pending, p2305 pending, p2311 pending, p2317 pending. Seven codes in all. The engine would not rev beyond 4,000 RPMs and then started to fall out again. Not driving revving in the driveway and then reading codes. Compression was 150 PSI on both Banks so I'm not concerned that the compression is weak it was a cold test. What about the ECM being bad or a plugged catalytic converter? This should give you something to work with and I appreciate your assistance. Thank you.

Hi Jeff Herman,

First you will need to repair all plastics tubes that are cracked or broken, you are creating a pressure leak with the positive crank ventilation. that the computer will try to compensate for vacuum leak.
second test fuel injector continuity at the connector with the injector to verify continuity. (see link)

https://www.2carpros.com/articles/how-to-test-a-fuel-injector

After you test injector electrical continuity erase codes from system, check to make sure you have no air leaks or vacuum related. notice attention on the one side cylinders 2,4,6 these are on one side.
Please run down these guides and report back.
when you erase codes read again to verify and report codes.
as for the coils you can swap one at a time from other side of bank from cylinders 1,3 and 5.
I am glad to help you, If there is anything else we can help you with please contact us again. Thank you for choosing 2CarPros

Cheers, Nick

Here's the update on the Liberty. All injectors are clicking, all have power supply, all have pulse. Have not been able to remove connectors to test individual resistance on each injector or gotten around to checking spray pattern. All six coils have spark. Repaired leaks in the breather tube with a fabricated tee. Latest code read was PO300. Still no response on 2,4 or 6 when coil is disconnected. Need to check resistance of those three injectors possibly they are bad. Thank you for your assistance let me know what you think and where we go next.

if you repaired leaks and have cleared codes and after running you get p0300 multiple misfires. The next step is to swap if possible coils with others clear memory and rescan.
cheers, Nick

Would this be in the secondary windings?

Can you swap the coils one at a time with a known good one brand new?

Yes you can i think they are all the same you can swap cylinder 1 with cylinder 2 and so on when you rescan it will give you codes for other side.

First I want to get a resistance reading on injectors two four and six.

Why would there be no change in RPMs if I have spark in those cylinders? Is that an indication there's no fuel even though there's fire? Those plugs are sooty black.

if the plugs are wet of fuel that means there is no spark, that is why i recommend swapping to see what is the other side going to do..

Before I fix the air leak the plugs on one side were almost white and on the other side were dry carbon black. Not wet filled with fuel. After I fixed the leak cylinders to four and six are still carbon black and one three and five are starting to run richer. I have to do some more testing especially on those three injectors check the resistance won't get around to that until tomorrow as it's 35° out here now again.

Good afternoon. All the injectors measure 10.3 ohms I took them out and cleaned them but was not able to test a spray pattern but I swapped the three no one working ones to the other side cylinders two four and six. There is also quite a bit of oil buildup inside the plenum. I'm including pictures of that and some discoloration on the injector connectors but it's on both sides even the working one.

My internet is down and it takes forever to send any pictures so I'm going to clean the plenum and try to read codes if it runs.

Update: I put everything back together ran it and got codes for secondary circuit in coils b d and f. Cleared the codes ran it again and all I got was multiple cylinder misfire.

multiple coils on one (what cylinders)and did you swap them?

It started snowing, LOL. You want me to swap one three and five with two four and six?

yes and clear codes and retest to see if codes have changed.

I swapped the coils side to side and got the same code random multiple cylinder misfire po300. It occurred to me that I was causing some codes when I was pulling the coils off and testing for dropping RPM. I drove this vehicle barely 10 miles closer to where I could work on it easier and it had trouble getting over 2,000 RPMs, it had trouble shifting unless I let off the gas, and obviously it had no power. Read the codes when I got home po300, PO700, po562. I think I have to get it running on all six before I can worry about the transmission issue. I also noticed that the coil on cylinder one jumped off because I did not have them bolted down for this short trip so that may have been causing less power. Finally did something I should have done in the first place and check the oil to see if there was coolant in there and there's not and there's no oil in the coolant so I'm assuming the head gasket is okay. Also my preliminary compression check of 150 on cylinders one and cylinders two indicates that Cam's are working and head gasket is okay. So what's next? I'm trying to get a hold of a COP tester to check the coils while it's running for secondary coil issues.

The next is to put things back together make sure your coils are secured clear codes.
first start engine and idling using a test light (remove injector cylinder one connector)check to see you a pulse light on test light while is idling.
second if it is pulsing light it means you are okay there replace all spark plugs, and cylinder one ignition coil with a new one. once you have done that erase codes again and scan again this time with ignition on engine off, if no codes show then proceed to start engine allow engine to idle and watching the tester to see if any other codes appear then p0300, listen is the engine misfiring, remember any small vacuum leak can cause a misfire indication.
remember to replace the spark plugs.
this technical bulletin possible that it applies to your vehicle .
to run this procedure you will need a tester that you can check live misfires on the tester it will show the cylinders what there are doing while it is running (it will show all cylinders and have 0 and when that cylinder misfires the 0 will change. then when it is misfiring it should change to for instance 100 + or -. write witch cylinders show misfires.
see chart on Technical Service Bulletin.

cheers, Nick

Well, now that the vehicle is at my house I did a full compression test on it and I got bad results put it that way. Cylinders 1 and 3 were 175 PSI. Cylinder 5 was 160 PSI. Cylinder 6 was 50 PSI. Cylinder 4 was 60 PSI. And cylinder 2 was 100 PSI. Probably a bad cam. Then I wanted to check my tester to make sure something wasn't happening it is a Matco. I retested cylinder one several times and only got 150 PSI. Not that it really matters with those other numbers. So I don't think we need to replace plugs or check anymore coils or anything until we determine what's going on inside the engine.

yes were right if you can do cylinder leak or go to tear down not waist any more time read the tech bulletin and move forward.

cheers, Nick

Dropped a little oil in cylinder number 6 this morning and did a compression test and got no change 50 PSI. I'm suspecting something in the valve train. Apparently these engines are known for breaking the rockers or displacing the rockers. Also dead lifters. Obviously stuck valves and dropping the valve seats which causes the stuck valve. Looks like the valve covers coming off.

I don't see anything out of the ordinary underneath here. Everything looks intact. How do I turn the engine over by hand so I can watch the valve train? Do you have any other suggestions?

it is time to tear down start with valve covers you will be able see cam lobs and move your way down, if you had a bore scope you can see inside, valve and combustion area. the best way is rebuild short block ask around for prices.

It's not my vehicle I'm just trying to help somebody out. Is there no way to turn the engine over by hand to see if the valves are stuck?

you can insert a socket in front of the crankshaft and use a ratchet, or lift vehicle and go to the flywheel.

That's what I figured but it doesn't look like it's easy access.

Pull the plugs out and use the drive belt to turn it over. Been able to do that on many 3.7s. If nut a strap wrench on the crank pulley with the belt off works. Or a faster way would be to use your compression tester. Pull the one way valve out of it and use it like a leak down tester. Rotate the engine so both lobes on 6 are up, apply some air pressure, air rushing out the exhaust or intake (they normally drop the exhaust seats) and you have the culprit. If it's a bad seat the rocker is going to be very loose as well on that valve.

Both lobes up at the same time or intake and exhaust separately.

I think that was a dumb question I retract it.

I don't really know what I'm listening for I'm getting air leakage into the intake manifold when the intakes are up. I think that's where the air is going and I was getting some air out the exhaust. If you could explain this a little more I could test again.

Okay, if the lobes on the cam are up so the valves should be closed because the rocker arms are on the lowest part of the cam you shouldn't hear any air through the intake or exhaust, you might hear a little through the oil drains because no piston seals perfectly, but if you are hearing air out the intake the valves are bad and the heads need to come off. At that point it doesn't matter if it's intake or exhaust as they are leaking. Those engines tend to lose the valve seats or the lash adjusters will pump up hard and the rocker will push the valve down and just touch the piston as it returns and you get a leak.
If you opt to replace the heads rather than rebuild them, be careful as to which ones you get, they are different over the various years. You would need the ones from an 05 or 06 for them to work properly.

If this were mine I would do it for fun. And to learn as it it's been a while since I've done a head. Since it's not mine and it has 260,000 miles on the chassis I don't think it's worth the money for the owner. Supposedly a new used engine with 110,000 Miles was put in around 200,000 so it should have 160,000 miles on the engine.

I would agree with that, including the ownership provision. I would price it out and see what the owner wants to do.