DODGE RAM FORUM banner

1 - 4 of 4 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter · #1 · (Edited)
Hey guys,

I have a 2011 ram 1500 5.7 with 103k miles. Long story short, misfire on cylinder #3 right after turning 100k miles. Drove it like that for about 3k miles while keeping rpms under 2500. Any higher and it would flash check engine light and run terrible for a few minutes but it would clear if you let go off the gas.

I found a local mechanic to do the job of pulling the cam and replacing lifters. Will post part numbers if anyone is interested. Replaced the cam/lifters and while at it, oil pump and water pump. Now that everything is put together, started it up and it still misfired, now even at low rpms. Initially we thought it was the ignition coils because they were corroded and replaced with new. Clear the ECM by removing the fuses (m28-m33) and turning the key to on then started it up again. It ran great for a few minutes until we revved it up to 3500 rpms and then engine light came on and started to run extremely rough(misfire), worse than before we even changed the ignition coils yesterday.

Now we're at a loss, mechanic put everything together the right way, cranked the engine manually to make sure everything cycled right, etc, etc. There is no engine noise, ticking is gone. Just a bunch of white smoke that smells like oil and misfire. Checked the plugs, all good and no oil on them. Will do compression test tomorrow, test fuel injectors and hopefully won't have to tear it down again...

Has anyone else gone through this rebuild before? Is there some sort of relearn procedure that needs to be done maybe? Any feedback would be greatly appreciated!
 

·
Registered
Joined
·
335 Posts
There are alot of things that can go wrong when the engine is opened up and procedure isn't followed ... I would do a compression check right away - you should not have smoke at all. If you have two adjacent cylinders reading low, its likely the torque order wasn't followed correctly making the head gasket not seal right. Also check for excessive blowby in case the leak is going into an oil passage.

There is a relearn procedure that needs to be performed - its called a "Cam/Crank variation relearn", and it needs to be done whenever anything was mechanically changed with the valvetrain, camshaft, or the camshaft/crankshaft position sensors.

It just makes the PCM forget the gradual "bias" adjustments it made to compensate for normal wear and tear of the engine and its sensors. If something was *really* worn, the PCM would of compensated heavily for it, meaning it will be very confused when the part is replaced without "telling it".

A dealer would have to do it, since it can only be done with the fancy wiTECH scan tool. You should just be able to tell them that you replaced the lifters/cam and you need that procedure performed and they'll know what you're talking about.
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #3 ·
I appreciate the reply! We found the problem. It ended up being the pushrods. For some reason everytime we adjusted one, another one came out of place so, the valves wouldn't fully close losing compression. We had to align each individual push rod in the rocker cup perfectly and do a test compression on each to make sure everything was aligned perfect. What ended up happening the first time, I guess one of the push rods wasn't sitting in the rocker just right and it popped out while under load. Truck runs fine now and hoping it will stay that way. Will take it to the dealer to have the ecm reset like you said. Thank you!
 

·
Registered
Joined
·
1 Posts
I appreciate the reply! We found the problem. It ended up being the pushrods. For some reason everytime we adjusted one, another one came out of place so, the valves wouldn't fully close losing compression. We had to align each individual push rod in the rocker cup perfectly and do a test compression on each to make sure everything was aligned perfect. What ended up happening the first time, I guess one of the push rods wasn't sitting in the rocker just right and it popped out while under load. Truck runs fine now and hoping it will stay that way. Will take it to the dealer to have the ecm reset like you said. Thank you!
I had the same issue. Replaced cam and lifters then the truck ran great for 1100 miles . Now its got a #4 cylinder misfire. Is it possible that the pushrod got out of place after 1100 miles??
 
1 - 4 of 4 Posts
Top