Dodge Owner Forums

Dodge Trucks => 3rd Gen Rams => Topic started by: thehatter on March 08, 2016, 06:15:02 am

Title: 4.7 Failure...I need help from a Ram Pro, PLEASE
Post by: thehatter on March 08, 2016, 06:15:02 am
2002 Dodge Ram 1500 Quad, 4x4, 4.7 (N code), auto, longbed, 265/70r17, oil changes every 2k-2500 mi, 154K total, No mechanical issues except the Tranny died on a raod trip at 79k.

Background:
I was experiencing a slight vibration, felt like rear drive train to me. We found a bad carrier and center U. Swapped them out; changed my studs to my summer shoes; took the truck for a drive and still had a slight vibration. Went home and parked the truck.

Problem:
I went out in the morning (truck parked over night on very slight incline, nose down), and it started, but ran on 4 or 5 cyls.  I took it down to my buddy who is the closest thing to a professional mechanic in the area.  He ran the codes and got back 3 different misfire codes on 1,2, and 4.  He pulled the plugs and coils, they appear to be OK. He did a cursory pressure check on 2,4 found very little. At this point he's thinking maybe head gaskets.

There is no condensation, foaming or any other indication that would immediately say "head gasket".  He hasn't had any time to go any further with diagnostics. We don't have access to engine/car computers or fancy equipment out here in the boonies.

I have been reading a lot about different issues with the 4.7, mostly sludging, valve failure.

I really need someone who can give me real world ideas about what might be wrong.  This is a daily driver, not a cream puff or hot rod and i really can't afford new engines etc.

Help ! Please !
Title: Re: 4.7 Failure...I need help from a Ram Pro, PLEASE
Post by: ERT on March 09, 2016, 03:29:58 am
I sure wouldn't jump to a head gasket failure just yet. A scan tool is definitely needed to do this correctly. I would start by moving spark plugs and coils around to see if any of the misses move. Just because they look ok doesn't mean anything, especially the coil packs. If that does not unveil anything, then move an injector if needed. I have seen in the past where the lining in the fuel rail has started to come off and plug injectors.

Good luck
 :cheers:
Title: Re: 4.7 Failure...I need help from a Ram Pro, PLEASE
Post by: pfi-tech on June 02, 2016, 03:15:25 am
It does seem odd that more than one cylinder is missing, having said that if there is a major contamination of some kind into the fuel that could do it. I would try an aggressive fuel cleaner if you have to drive it and look into the electrical in the mean time.

If you cant find any electrical problems id check the fuel filter for major contamination, maybe just change it out anyway. might have to take the injectors out and have them looked at and cleaned if necessary.

hope this helps!
Title: Re: 4.7 Failure...I need help from a Ram Pro, PLEASE
Post by: RamCharger87 on August 26, 2016, 08:57:17 pm
So, you had a compression test done, and found low pressure in a couple cylinders?

Sounds like you may not have the compression necessary to ignite the fuel mixture.

This can be either bad piston rings, or a valve staying open in one of the cylinders.
Title: Re: 4.7 Failure...I need help from a Ram Pro, PLEASE
Post by: soonerb on December 30, 2016, 09:13:38 pm
Is this thing fixed?