Hi all!

My husband and I are thinking about buying a 2nd gen Durango. At first, we were leaning more toward the Hemi than the 4.7L. The main reason being, that in my line of work, I have seen a lot of bad 4.7s. My dad has a Dodge truck salvage yard, and we have lots of calls about 4.7s, and almost half of the 02+ trucks we've bought have a bad one. But after checking into it a little, all of the bad ones were 02 year models, the one with the 16 tooth crankshaft.

Then, I started seeing some Hemi-equipped Durangos for sale on eBay or craigslist with blown engines. After doing some more research, it looks like 04 and maybe 05 was a bad year for the Hemi. This is news to me, I had assumed they were pretty well designed.

Short story long, My husband is very mechanically inclined, and we're thinking about buying one of these and replacing the engine. We're just trying to avoid replacing an 04 Hemi with an 04 Hemi just to have it fail 6 months later. Does anybody have any info or a good resource on which year models of the Hemi would swap with minor changes? What is the weak leak on the earlier Hemis? The best I can tell from my research is that the rods are coming loose and wreaking havoc inside. An 04-05 Durango or an 05 Ram is shown as the only direct interchange. I assume that an earlier Hemi, say an 03 model from a Ram wouldn't work due to MDS. I think that came earlier on the Durangos and the LX platform than it did on the trucks.

Sorry for the long post, and thanks in advance for any help! If all else fails, hubby is talking about dropping a 4bt Cummins in it. (help me) Maybe sticking with the 4.7 would be a better idea, since it seems like its issues kind of got straightened out.

 

Sherry:

The 4.7 is a good engine. You get some bad apples in any bunch. If taken care of properly and not left to run on overextended oil changes, they usually last quite a while.

As far as the Hemi goes, you are correct that the 04-05 model years had issues with collapsing valve springs as well as rods coming through the side of the block.

MDS did not appear on the Durango until mid 05 for the 06 model year.

I would say if you can find one with a blown engine and put a good one on, you will have a great set of wheels for a long time.

There are plenty of places that rebuild them. I would be careful though of installing an oem junkyard motor for just the reasons you listed.

My 04 SLT Hemi's engine was replaced in 2008 due to a dropped valve. The build date on it was 01/04.

Don

 

The 4.7 is not a bad engine, but it's major flaw is that the coolant channels in the block are too close to the cylinder walls. When coolant is left too long without being changed it becomes very acidic and the fact that it does not have much to corrode to get into a cylinder is why you see the failures. This engine DOES NOT rebound well from an overheat and at best will cause a head gasket issue, but usually damages the heads as well. The engine also is very susceptible to problems due to oil sludging.

Of course both of these issues are avoidable with reasonable care, the problem is - only about 10% of vehicle owners do maintenance when it's required. Some engines will run forever on just marginal care (the venerable old LA 5.2/5.9's come to mind here), but the 4.7 IS NOT one of those engines!!!

I have an '02 4.7 in my Grand Cherokee, but it's on Overland so I have the HO version of this engine. LOT of differences including a forged crankshaft. But I'm still **** about my maintenance.


As far as the Hemi goes, I think that the '04 and the '05s are the class of the lot. No MDS and it's inherent problems and the valve springs were changed in early '04 and caused the dropped valve problems to be a thing of the past. Only about 20% of the '04s had the older springs.

I modify these engines as a sideline and do some sub-contract work for a local 4x4/Performance shop and I don't see any real issues with the '04 & '05 Hemis, at least the 80% or so of the '04s that had the stronger springs from the factory. Although with any major mods like an aggressive cam, I'll still swap to 6.1 springs/retainers and rods...

 

Thanks for the responses. Good to know that the Hemi's aren't as bad as I was reading. I'm sure everyone who blew an engine at 65k miles wants to let everyone else know about it, but you don't hear much about the good ones! I'm also a little relieved as my Maggie has the 5.7 in it, and we just turned over onto 67k with her!

We'll just keep our eyes out for either one, 4.7 or 5.7 doesn't make too much difference for me in the Durango, we're only getting one because my husband refuses to get a minivan.

Thanks again!

 

I would get the 5.7L and the extra 100 horsepower,
FF

 

Ill try to make a long post short, glad if you have a D already.

I have an 04 Limited with the HEMI engine, my engine blew at 133k due to hydrolock. The best engine to drop in is an 06-08 HEMI from the Ram 2500. 2500's don't have MDS and have the holes for the front diff mount (4x4 only) already drilled and tapped, as well as the ground screw on the front of the block. The front diff mount hole aren't used in the 2500 so you will have to clean the holes out. Another difference is the oil pan, hopefully you can salvage the one from the other engine, and the windage-tray, oil pan gasket is re-useable although as piece of mind you can replace it. You can swap out the plugs on the harness for the new ignition coils or you can swap valve cover gaskets and older coils (also re-useable gasket).....DO NOT use the new throttle body!!! it is not compatible with the older PCM's. Lastly (i think) is the intake manifold, IT IS different but i was still able to use it with a slight modification to the manifold harness.

-Hope this helps, good luck on your project!