We just did head gaskets on a 2016 3.6 dodge ram 1500 and truck was running perfectly for a few weeks. My daughter borrowed the truck and when she returned she shut it off and came an told me the engine was smoking. I turned the key forward and the needle in temp gauge was maxed out. Poppwd the hood and noticed right away the bottom rad hose had come off. i dont think i ever seen an engine that hot. I let her cool down amd tried to start it...crank no start.

Pulled the codes and got cam sensor errors. Changed both cam sensors. Still crank no start. Almost wants to start and has even ran for couple seconds and the gags out like it is fuel. Noticed oil dripping down the back of the engine from oil cooler.

Pulled upper intake and did compression test. 150psi+ on all 6 holes. Changed oil cooler while we were down there. Old oil cooler had got so hot it melted the plastic around the orings and made it brittle. Thus the oil leak.

Tested injectors...all ohm'd out within spec. Figured id try new injectors anyway since they are mostly plastic and maybe they were leaking or not spraying properly.

Still crank no start.

Fuel pressure 58psi
Cam sync is sync
Not getting any codes whatsoever.

Our autel maxysis has live data pids for exhaust and intake cam positions. The differnce pid is about 10 degrees. That pid seems like its the same as the differnce between desired positions minus actual position pids...is that normal

Cam phaser marks are lined up like they are suppose to be still too.

So im having a hard time giving up on this engine and spendings 5000 bucks on a used one. Am i right to think that if compression is good then this has to be a fuel or spark/timing problem? And if it had jumped a tooth on the main timing chain or if there was internal engine issues we wouldnt have perfect compression... right?

 

Compression looks good. What do the plugs look like? Verify you are getting injector pulse, and coils as well.

 

It seems to have good spark and injector pulses look normal on live data.

Actual cam positions are all off 10° from desired cam positions though

 

Did the chain slip??? That seems rather unlikely..... Still and all, even if it did, I would expect you would hear some variety of internal combustion noises... even if it was backfiring. Does that have the variable valve timing gizmo on the camshaft?

 

Yes each cam has a cam phaser. Dual overhead cam each bank has two camshafts. It would seem strange for all four cam phasers to be having the problem at the same time. We have not at the front cover off main timing belt because it's quite a chore to get into. Each bank has a chain that goes around both phasers and the timing marks are lined up the way they're supposed to be on those chains. But I guess the main timing chain could have slipped or stretched.

 

10 degrees is a LOT of stretch.....

How many miles on the engine??

Even if the chain has stretched that much, I would still expect the engine to at least try and start. What do the plugs look like?

 

It does try to start. Once in a while if you crank it long enough it will even run like a bag of crap for a couple seconds.

250000km

 

Try hitting it with some starting fluid. See what happens.

 

Oh, it appears you have two threads going on this topic. I posted a few things to check on your other thread. Maybe delete the other thread since this one contains more information.

-Rod

 

Ether doesnt help. Im 99 percent sure Its not a fuel issue.