2009 Dodge Ram keeps breaking valves

[tunedlaramie]

Hey everyone. I hope that y'all are having a better day then me.

Any way it all started about 6 months ago when my truck had the bad lifter problem. Anyway, I had them replaced and swapped a 6.4l cam in my 5.7l hemi. Anyway I made the mistake of keeping stock valve springs and I ended up bending a valve. Got that fixed up and swapped in some 6.4l OEM valve springs. Then a few months later things really went bad. Suddenly one of the valves broke off and destroyed a cylinder head. Got that fixed up and now a few weeks later, it suddenly lost all power and shut off and the check engine light was flashing. I haven't let someone open up the engine yet but judging by what it is doing, I'm pretty sure that it has broken another valve. Both off these times the engine was in low rpm when it happened. This last time I was cruising at around 2000 rpm I think. I wanted to speed up cause of a hill when I noticed that it didn't have any power.

Any ideas or anything would be really appreciated. The only mods in the truck are a custom tune, oem 6.4l cam, and OEM 6.4l valve springs.

Thanks

 

[McBroom]

Hey everyone. I hope that y'all are having a better day then me.

Any way it all started about 6 months ago when my truck had the bad lifter problem. Anyway, I had them replaced and swapped a 6.4l cam in my 5.7l hemi. Anyway I made the mistake of keeping stock valve springs and I ended up bending a valve. Got that fixed up and swapped in some 6.4l OEM valve springs. Then a few months later things really went bad. Suddenly one of the valves broke off and destroyed a cylinder head. Got that fixed up and now a few weeks later, it suddenly lost all power and shut off and the check engine light was flashing. I haven't let someone open up the engine yet but judging by what it is doing, I'm pretty sure that it has broken another valve. Both off these times the engine was in low rpm when it happened. This last time I was cruising at around 2000 rpm I think. I wanted to speed up cause of a hill when I noticed that it didn't have any power.

Any ideas or anything would be really appreciated. The only mods in the truck are a custom tune, oem 6.4l cam, and OEM 6.4l valve springs.

Thanks

Sounds like the cam is out of time. Not clocked in/degreed correctly. The timing chain is probably the #1 problem in this case. Too much stretch in the chain will cause this repetitive issue. Another thing is the difference in the pushrods as in the length n diameter.

Blue Mule

 

[tunedlaramie]

Thanks for the reply.

I didn't even think about that. I'm gonna try to give the shop that worked on it last time a call and ask them what they think happened and what they think about that theory.

Just curious how would an engine run if the timing was off?

My truck did make nice power, but when I started it up it would hover at over 1000 rpm until I set it in drive.

And also at idle the rpm would jump up and down a bit, not a lot though. It didn't do that as much before the last time it broke as it did before the first time.

Also the morning it broke down, I started it up and when I pressed on the gas ,I noticed that it didn't have any power and it sounded like it was misfiring but the check engine light didn't flash. Then I let it warm up a bit and I didn't notice anything after that.

Thanks again

 

[tunedlaramie]

I talked to the mechanic and he said that last time the valve broke at the stem not at the bottom. He said that he would check the timing but he doubted that that would be the problem since it would have thrown engine codes.

But, last time they did mention that the springs hadn't been centered when they opened the head up. I'm starting to think that it is missing the spring locators and that it caused the springs to walk.

Could that cause a valve stem to break?