Timing chain jumped? P0175 with rough idle

[rsimon]

Hello again,

we spent the day on measuring the things one by one. I took the Jeep there and exchanged the parts one by one, but nothing helped.
Checked the coils, changed the injectors, checked the wiring from the PCM to the coils and to the injectors.
Nothing helped.

In the afternoon a guy brought a Bosch application that sw has a Chrysler 300c profile. It said everything is all right. With an oscilloscope they measured the camshaft+crankshaft+Injector1 signals and they said it will be not the timing chain, the fireing order is right and in time.

The only thing they will check tomorrow to remove the exhaust , maybe the catalisator is dirty or broken. But we have no other idea...

I could move the car from a building to another, max 150 meters, but the car really feels bad.

I also have an LPG system in the car, but i used it for 2 years without problem, and that was the firs we disconnected, so now it is switched off.

i recorded a video, maybe this helps a bit more

VIDEO0058 - YouTube

VIDEO0058 - YouTube

One more thing that was interesting: we checked the sparks again today, an the sparks in the cylinder 1 and 6 look wet more than the others. all the others are brown but these were like overfueled. but the coils the injectors were exchanged and we couldt really figure out what can make only those to wet

Any idea is appreciated since we do not have anything to continue with.

[ivanford]

Have you checked the compression on all cylinders ? Is it possible you have a slightly burnt valve ?
I believe LPG is harder on valves etc.
Is it possibly an MDS solenoid problem on these cylinders?

[rsimon]

the service didnt have enough deep tool to measure the compression precisely, they only did it with hand and said it "feels" good. they need to make a tool, but they will do it.
So you mean it can be a valve, a valve spring brake or MDS Solenoid? To check these we have to take the engine apart. or is there a trick to check them one by one by cylinders?

[rsimon]

Please correct me if im wrong:

if it is the MDS solenoid i would get an error code and would be able to run the car without the MDS kick on
The valve can be checked with a proper compression measuring
the valve spring would have some noise?

[ivanford]

You could remove the valve covers easily enough to check valve springs and make sure all valves were opening and closing etc. It would only cost two new gaskets. Can you get a camera down the spark plug holes to look at the tops of the pistons etc. I think if it was a hardware failure of some sort with the MDS as opposed to an electrical fault you might not get any error codes. Have you drained the oil to make sure there is no shrapnel in there.

[Toms Black SRT8]

Man , that thing sounds absolutely horrible . You should definitely do a complete compression test on all 8 cylinders . How does the engine oil pressure look when running ?

[rsimon]

Good news for today!!!!!!!!!!!!!!!

The Valve head was removed today (to check the springs as you mentioned) and the mechanic found 2 intake pushrods were off on both sides (at cyl 1 and 2). they simply placed them back and reinstalled the valve heads. Now the engine is like new.

The only thing i dont understand how do they came off?

Of course i ordered a set of gaskets and 8+8 intake and exhoush pushrods, and when they arrive we will change them.

For me it was a big learn. This engine is not complicated so much, but this issue was caused by such a small issue.
Thanks to God it seems to be fine and hope i will not have any issue for loooooong time

Thank you again for the help!

[Toms Black SRT8]

Good news to hear . Sounds like you got lucky .

[ivanford]

Is it possible that you have a couple of bad hydraulic lifters that have bled down too far and let the pushrods jump out?
What oil do you use, MDS cars require 5w 20 or 5w 30 oil.
When did you last change the oil, I believe it always looks quite clean running on gas, even though it might be in there a long time.
I would build it up again, do an oil change and run it for a while, see how it goes, before doing anything else.

[rsimon]

I always use Mopar 5W20 and changed the oil in September, max 3000km ago. i really keep the 12000 km oil change period, not a big cost and good for the car.

just attached the pic. so you suggest to take it apart again (cause it is up and running now) and check the hidro lifters one by one? to remove everything and check the parts again? or run it as is, and if there is no problem for 100km than we can say good?