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Dodge Durango 4.7 SLT, Trailer Package bought Dec 2002

4K views 4 replies 2 participants last post by  Hummer 
#1 · (Edited)
Went to upstate last week, rig ran absolutely beautiful for 130 miles (it turned over 265,000 going up) and made a couple stops here and there, pulled out and it was purring along. Then it developed a slight miss. Ten miles later it was hard to keep it running, had to rev it at 1200+ rpms to keep it going.


Had to leave it at buddies' house and get a rental car to get us home. Went back next day with car hauler and loaded it up and brought it home to a mechanic buddy.
Codes indicated No 1 not firing and iffy codes on 3 and 5. Pulled spark plug, wet, put in new plug and ran it still wet so installed a new coil. That cleared up part of the problem. Decided to go get coils and got three Borg Warner so they would match. Put them in 1,3 and 5. Still runs but rough.


With it cold we cranked it and felt the exhaust manifold, cold on the front four cylinders. Real hot on the four rear cylinders.


Since there is no distributor and understand this thing is fired by computer, I am thinking the computer must be bad?


Another hint, about a month ago filled up with gas drove 6 miles down to barbershop, got haircut came out cranked it and it was running rough. Shut it off and cranked it again and it purred. This happened twice in about two weeks, Rough, cut off, re-cranked and ran fine.


Engine has had Mobil 1 10W30 since new. Tranny fluid changed on schedule. Original alternator, water pump etc. Had front in rebuilt about 30,000 back with MOOG parts with grease fittings as I planned on running it 400K.
Anybody got any idea of what is happening here?
Thanks yawl
 
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#2 · (Edited)
Update: I made appointment with a guy here that the dealerships take their cars to that they cannot figure out what is wrong with them. I have to get it to him Nov 3 and he says he can start on it Nov 4.

Really miss having it at home as it has been a great ride.

FWIW I was at a used truck place the other day thinking about a 4 dr diesel pickup and mentioned the above problem. He said they had seen multiple Dodge Engines dropping valves. Can anyone confirm such? I am thinking a dropped valve would not shut off engine firing the front four cylinders.
 
#4 · (Edited)
Friend called today. Replaced:
No 1 spark plug coil( this cleared up a lot of the roughness.
Crankshaft Position Sensor (showed bad wave form on analyzer)
All spark plugs as they were all fouled from the rough running.
Those three cleared all codes but still running a bit rough.
Further testing indicated injector No 2 cylinder bad so it was replaced.

Now if I read it right all that is involved in changing out a Crankshaft Position Sensor is the tools and a sensor, remove old one, put in new one. No aligning No 1 TDC etc like putting in a distributor. I think I am going to be carrying a spare one from now on. Also plug coils

UPDATE:11 15 2014
Ran diagnostic with a Snap On analyzer, fixed everything it called for. No codes registering and still does not run right. Crankshaft position sensor changed, all new plugs (others fouled to H&G. Found hole in vacuum line under air intake. Brought it home and another code popped up on it before I got it home. It will not idle at all.

In Virginia now for a few days and when I get back I will put new axles under the equipment trailer I just got which needed new ones so I ordered a pair of 5200 lb axles and new spring assemblies , load the Durango on it and haul it back to see what the new code is. I am thinking of going ahead and changing the throttle position sensor. If the next thing doesn't do it I will haul it to the Dodge place and pay for a full diagnostic to be run on their equipment.

I understand the Dodge analyzers will find more than the Snap On unit which begs the question why won't Snap On do so as well.
 
#5 ·
The rest of the story. It was finally determined that a valve seat had dropped and I now have a Jasper engine in it with 5000 miles on it and it runs like a champ.


The first place that rebuilt my engine apparently did not retorque the heads when they test ran it and it blew a head gasket at about 600 miles. The owner of the shop figured no more engines from them and ordered the Jasper which I understand has a better camshaft for a little more power.
 
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