Dodge Ram Van 1500, 5.2L (4,000 miles on new motor)
On a cold morning, the motor started ticking at low RPM, so I pulled over to check it out, but when I let off the gas it stalled out. I couldn't get it started again and after lots of diagnosing I found that the timing chain broke. I sent it out to have it replaced (since the rebuilt motor has a warranty on it).

The shop got it all back together, but it still runs rough. They put it on the tester and told me is was an injector misfire on cylinder 2 and 7. They wanted $800 to replace the 2 injectors so I towed it home. I'm not giving them any more of my money-especially at that price.

So anyway, put new cap, rotor and wires on to rule out cross-arcing. Also pulled all of the injectors and soaked and tested each one. They all spray a nice pattern and open/close when i give them voltage. It starts and runs, but it's really rough. I just ran a compression check and all cylinders are at 140psi except #3 and #5 which are at 0.

What should I look for next? I know I don't want to pull the head with a van, there's hardly room to work as it is.

 

when the timing chain went it could have bent rods, damaged valves/pistons......and i thinks this is what happened IMO

 

That's what I was worried about, but I always heard that the 318 Magnum was non-interference.

 

I would guess most likely bent valves.

 

Isn't it still under warranty? Take it back to the builders.

 

The builder only gives a warranty up to $30 an hour. This was a crate motor from Tennessee. It's cheaper for me to do it myself and have the builder reimburse me.

Still sucks though!

 

so this "rebuilt" motor has experienced a broken timing chain, a misfire on 2 and 7, and now has zero compression on two cylinders.

3 and 5 are adjacent right, so it could be cracked head, head gasket, bad valves, or anything.

how much money have you got in this rebuilt motor and how good is its warranty. you may need a lawyer in addition to a mechanic. a lot of junkyard motors get passed off as rebuilt, with a 1 year/12,000 mile warranty, when there's nothing at all rebuilt. what's it called - spray and pray, deny and delay, hoping to reach the end of the warranty... another trick is to try and charge for unrelated stuff, like injectors, and throw in another prayer....

i'm a little baffled by how you got from misfire on 2 and 7 to zero compression on 3 and 5. if might half *** run on zero compression on one cylinder, but not two. and the pcm should have recognized the misfire on 3 and 5. i'm just confused.

 

I think the shop I took it to were idiots. Probably just hooked it up to the scan tool and read the first code that came up. I asked them all sorts of things about doing a compression and leakdown test. They told me that I didn't need to do that.

That's precisely the moment that I realized I need to get out of there.

I put the motor in and it looked completely clean and rebuilt. I even torqued the rockers, head bolts, and cam sprocket. Everything was torqued to the right spec. I even remember seeing that the underside of the pistons were brand new when i put the pan on.

Not to throw these guys under the bus, but the place is called Grooms Engines. I'm sure they do good work, I think I just have bad luck.

 

hows the oil look? if its milky theres a problem with either heads or head gasket....

 

I take it this was a short block? I would do a leak test to figure out where the problem lies. These stock heads are not the best.