Well I managed to drag home another project.

Picked up an 06 megacab 1500, looks like it probably needs an engine. Listing advertised it as has "hemi tick" mechanic diagnosed as lifter issue. Truck is pretty rust free except the fender for some reason. Very strange situation, but fenders are easy to swap.

I feel we're far beyond simple repairs for the engine. Seems like a misfire, no fault codes surprisingly. Need to check for stored codes yet. Also has a squeak, could be fan/accessory squeak but I'm not sure. Oil is slightly overfull, coolant is full/clean. Starts dropping out oil pressure after running for 5-10 minutes. More diag to come but I'm planning for an engine swap or full rebuild.

I'm researching a 6.4 swap but curious how much from the 5.7 can be used. I've read some swap articles but they're all on 4th gen trucks and im not sure the wiring will match up as easily on the 3rd gen 5.7.

 

Well had a minute today and hooked up the scanner, had p0300 random missfire and P0308 cylinder 8 misfire. So I guess we'll start with a compression test when we get to it.

 

Those generation engines generally didn't have lifter issues; not saying it definitely isn't but it isn't as likely as say a 2009+. Can you swap a VVT engine into your truck? Because you have a 2006 it is possible, but not plug and play. A factory 6.4 and your current 5.7 have absolutely NOTHING in common. To use the OEM 6.4 you'd need to rearrange your accessory drive as the two are different; this is non-negotiable. You'll need to figure out what PCM you can use; you might be able to get away with finding a 2009 2500 PCM, this was a one year hybrid setup with a 3rd gen body and 4th gen engine. Then you could just get it tuned for the larger engine. An early 4th gen PCM (like an 09-10) may work; I would contact Hotwireauto.com for specifics as these kind of swaps are their bred & butter. Regardless, some wiring harness alterations will likely be required. You will also need to figure out what trans you are going to use that isn't your stock 545RFE; it wouldn't be particularly happy behind a stock truck 6.4 (410hp/429tq) and even less so behind a factory SRT/Scat 6.4 (470-485hp/470-475tq).

 

Yea the research I have done, doesn't seem as plug n play as I thought originally it could be. Also picking up a 6.4 under 6g looks limited in my area within reasonable driving distance. Though some come with the trans so that would be an option but I'm not looking to open that can of worms either.

Much appreciate the input, I still need to break my teeth on a hemi. Never had one open so I'm excited either way.

At this point I think the 6.4 is a pipe dream maybe someday, but a 5.7 can be built well too for the same kind of money investment , less headache and time invested. In the end its a driver, not a tow pig. It'll replace my 4.7 1500 and in 6 months I'll pickup another lost puppy and start over again. Though I have really missed my mega 1500 I used to have, so this may stick around. I've been playing around on FRP's website. 2-3g for a nice cam upgrade functional with stock heads and torque converter.

As for what I have and I am dealing with immediately. I'd like to decide quick/soon if I should just drop n swap another long block hemi, used. They seem to be had with low miles for 2-2500. Not sure if that's fair, I'm not in the market, but reman can be had for 3-3500 so its a close game.

I ran a compression test today, with unexpected results. The cylinder variance take lightly, the plugs were very stiff in the threads and I had the same with my compression tester so a prefect seal might not always have been reached, the fact they all could surpass almost 160psi I was surprised to find, just based on how it runs/sounds. I think bent valve/dropped seat/scored pistons all can be ruled out. As you can see below #8 seems pretty healthy, so a misfire is not result of compression I don't feel. Now a failing lifter, would still provide decent compression I would expect, until it reached a point it no longer opened the valve at all, but it may limit intake/exhaust flow for decent combustion?

Looking at images and videos it appears one pretty much has to tear these down to block to get a good view of the cam/lifter areas. A quick oil sample provided lots metal particles so its safe to same something happened that should not have. Use that information as my nail in the coffin for buying a new/different motor.

 

The misfire code is for cylinder 8? 4 looks like the worst of the bunch, that one makes it 'out of spec'..... I would also point out that 4 and 8 are right next to each other in the firing order..... How likely is it the PCM is confused, and 4 is the bad cylinder???? (I know, pretty forlorn hope there....)

Unless you are thinking of going with a new motor, I would be real tempted to tear that one down, and rebuild it.....

 

The idea crossed my mind that the PCM may have "confused" the cylinders. Another note on cylinder 4 was a few CCs of oil in the plug bores before removing the plugs, may it be leaking valve cover/plug seal rings? The also made the coil packs look funky. and corroded looked.

Sorry you helped me remember some more information I had not mentioned. Also the plug gaps were very large, I'm thinking .080"+ so new plugs and possibly coil packs on the list as well. Are these hemis still in preference of copper plugs like the old magnums, or what do they prefer.

Just going straight off rockauto with midline replacement parts, melling, cloyes, mahle ect. I'm at about 1500 bucks, plugs, timing set, cam, lifters, water pump, gasket set ect ect Looks like a simple ring/bearing kit is 500ish, + machine work, of which I haven't a clue on. Needless to say were peaking that 2k mark in parts alone. Makes me lean towards a used motor. Ofcourse the used motors in the 2-2500 range arent from big chain yards so most likely no warranty, the used motors with warrantys are creeping in the 3k range. Another 500 bucks you can get a reman.

What year range hemi will interchange. I know this a non VVT/MDS motor but are there other difference or would any 03-08 hemi fit in? Im sure sticking with a truck engine to keep the accesories and such the same would be easiest but are car/suv engines the same internally? What year did MDS start

 

I am not well versed enough with the hemi's to say what will fit, and what won't.... Copper plugs are your best bet though..... For the money though, given the cost of a rebuild..... (not to mention time involved with the machine shop, etc....) Reman is startin' to look really good. If you got a good deal on the truck, you could probably change that fender, toss in a reman, and still be able to sell it for more than you have in it. If you plan on keeping it, so far as I am concerned, that would be a major vote for a reman... and engine with a warranty, that you can expect to get at least 100K miles out of.....

 

Me either, its looks like MDS was introduced on 05 though im not sure if that applied to the 1500 motor or just cars at first. I think I best stick to 3/4 ton motors if looking at used, or 03-04 motors if they all fit.

 

You can use any 03-08, with caveats:
All 03 engines do not have MDS nor EGR
04-05 1500 engines have EGR, 2500/3500 do not, neither have MDS
06-08 1500 engines have both EGR & MDS, 2500/3500 do not have either
Best plug and play for you is 06-08 1500 engine.

 

Well this popped up this morning, 04 1500 Hemi. Guy was desperate for cash it sounds like, I paid 900 bucks. Said he was installing new injectors and cant get #1 to seal, it sprays all over. I'm guessing he bent the rail or doesn't have something seated correctly. It seems to run smooth even with the leaking injector. Didn't run it very long obviously. Probably find some headers and replace manifolds n such while its out of chassis instead of dealing with it later in chassis, and can sneak the EGR out of the picture too then. Would love some long tubes but they seem hard to find, especially for the 2500 4x4 chassis.

One thing I noticed is the 06 has the coil pack with 2 boots straight down, this 04 has one boot straight down and wire coming off to the other whole. The cast mounts seem postitioned different also. Should I swap valve covers to use the correct coils for the truck? Does it matter?