Some of you may remember a post I made about 2-3 months ago regarding my truck misfiring and hitting a wall at 4000rpm and refusing to accelerate beyond that rpm range. Anyway for those that aren't in the loop, I ended up changing practically everything from injectors, plugs, wires, I took heads off and lapped the valves and checked for bent valves, bought new lifters, tried new egr, new crank and cam sensors, changed my coils to known good used coils, tested fuel pressure, compression test was perfect numbers and I scrutinized every aspect of the fuel trims and timing under idle and running conditions and even spent $160 on a brand new PCM....(which by the way Flagship 1 electronics delivered a great product! programmed to VIN and ready to turn key pcm well worth the money especially if you need it).

So anyway a mistake I made a year ago ended up biting me in the ***, I never replaced the cam after a lifter failed in June of 2018. I did however replace the lifters with brand new Melling lifters, but because my ex was rushing me to get things done I had to settle for a pinky finger down the lifter bore to feel if the cam lobe was suitable enough instead of taking my time and pulling it out to inspect like I would have wanted. So after throwing the kitchen sink at my truck and seeing some misfire videos on youtube of Hemi Rams with failed mds lifters, I thought their problems sounded startlingly similar to mine even though I don't have mds. I got my new pcm in the mail 3 days ago, it didn't fix the problem so I was set on going with my gut feeling and throwing a new cam in, so tonight when I took it apart I found this:




Here's as far as I got putting it back together tonight...tomorrow Radiator, plug wires and water pump and I'm done!

 

I remember. Good work and good luck. You put new lifters in again ro match the new cam ?

 

How much lift did you lose? Looks like the lobes affected ate not worn down too far by the picture.....

 

Replace your lifters again........

 

That'll do it....

 

Yes I did!

Since everything was recently taken apart, everything came apart fast. Thank God for the air ratchet!.

I got the rest put back together about an hour ago and Truck runs like a beast once more! I missed the power so bad! My Hemi Durango has *****, but not like this truck. Headers, K&N Cold Air Intake and Superchips tune sure make a huge difference vs same engine stock in the Durango...also 2 and a half inch exhaust piping I put on vs 2 1/8 on the Durango's stock piping.

 

I don't have a micrometer handy so I'm not exactly sure, I'd say maybe 40-50 thousands. To be honest compared to most cams I've seen eating the lobes, mine looked fairly good (good as in barely any lift gone where as some online were literally chewed out) maybe thanks to zinc additives I put in? despite the wear so I was skeptical to some extent that this would actually be the cause of the problem. The fact a crank sensor can see even a small change in engine rpm between each cylinder firing is how it can tell if a cylinder has a misfire and it starts to pull timing, so that small change in lobe height the pcm can detect because that cylinder is not firing as efficient as the rest. In my case it was one really bad lobe and

I blindly timed the engine as well because the oil pump was in the way and I couldn't see the crank sprocket TDC mark, several professionals online said it could be timed without so I wanted to challenge myself, I put engine to top dead center manually by taking a plug out of cylinder #1 and putting a spare pushrod in until the crank/piston leveled off telling me it was at top dead center (I didn't just drop the pushrod in the plug hole, I knew about how far it should go down so it wouldn't drop in). After I timed it, I realized I was able to see partially where the crank sprocket key was and compare it to several engine pics online to confirm I had achieved proper timing, Kinda proud of myself on getting it right semi blind and it runs amazing.

Was also proud of the fact my makeshift dowel pin I made out of a drill bit for the previous cam held up and kept the cam sprocket true.

Here's the lifter I pulled out a year ago from that cam lobe:



It was a cheap *** Rock Auto lifter I installed in 2015, went to Melling this time around, praying for good results!. And yes thats exactly how I pulled it out of the engine, roller gone, as well as the needle bearings. I sprayed the heck out of the oil pan with brake cleaner and stuck magnets to my oil pan and changed my oil 4x since still no trace of them and oil looks good. Less than 600 miles on the engine in the year since I initially had all these problems.