2003 1500 5.7 dropped a cylinder?

[Mike Wenrich]

My neighbor has a 2003 RAM 4wd short bed truck that has an engine miss. Shop says it is dropping cylinder No 6 and the engine needs to be rebuilt/changed. If an engine suddenly begins missing and gets the check engine light, is it certain it needs to be rebuilt? I'm not sure exactly what dropping a cylinder means. Maybe a valve or other issue? It does have a lot of miles. 235K. But has been well cared for with regular oil changes. It has been burning a quart of oil every 1,500 miles so I know the rings are worn or valve guides bad. Anyone have an idea what might be going on with the diagnosis? Maybe it's mainly in the heads? I don't believe a compression test was done or at least she was not told that.

 

[jws123]

Most likely a valve seat common on older rams you can have someone do a leak down test to find out. Is it a dealer or a private shop? Is it low on compression on cylinder 6 or what? It is alot of miles tho.

 

[Mike Wenrich]

It was at private shop with a good rep. But I don't believe they did a compression check or leak down. Still waiting for it to come back from the shop. She was quoted between 8-10K to repair.

 

[jws123]

It was at private shop with a good rep. But I don't believe they did a compression check or leak down. Still waiting for it to come back from the shop. She was quoted between 8-10K to repair.

oh hell no run far from that shop.... A older hemi engine used can be had for around 1k plus install figure 2k tops. Take it somewhere who will diag it correctly do a leak down test to seee if its a valve issue and compression check.

 

[Daw14]

Without a proper diagnosis,they may swap the engine ,but the issue might remain.

FInd a more thorough shop or request they dig deeper.

If they refuse, run away. They did not want the job.

 

[Mike Wenrich]

Going to the shop this morning with the widowed neighbor. I want to ask if they did a compression test and get the results if so.

 

[Mike Wenrich]

They did a compression test and that is when they came up with the dead cylinder result. Tested 1/4th of the expected compression. They believe it might be an exhaust valve hanging up. The engine will start and sound good at idle but as soon as you give it a little gas it misses badly. They suggested a new head. I drove it to her home from the shop and had to keep my foot on the gas at stops to keep it running. Missed badly and very low power climbing a mountain hill in our area. And the mechanic had to create a vacuum leak to keep it running. No rattles and no knocks. After clearing codes he drove it and the code did not come back until he got off idle and gave it pedal. New plugs are in place but old coil packs and wires still there. New coil pack on No. 6 did not improve it. They did not remove the valve cover to look at the rocker arm movement.

Strange that it sounds good at idle when starting but rough after giving it throttle. Maybe that is the indication for a valve.