So the wife calls me and tells me her check engine light is on in the Durango but it is still running fine. Pull the codes and it is for the cam position sensor. Grab a sensor and change it out. As I am in there I notice that the coolant is pretty dark. Check the oil and it is not even registering.

I am assuming there is a head gasket leak. Truck has 78k on it and has been maintained by me all its life with no prior issues. Did some google searches and didn't really come up with stock hemis. Has there been any issues with cylinder head castings or even factory gaskets?

I am looking for some advice on what to change while I am in there (this will be my first time tearing into a 3rd Gen Hemi).
Should I buy new cylinder heads or just get them checked? Head studs, valve springs etc? We are planning on keeping the Durango forever and I want a bullet proof package.

Any advice would be appreciated.

Thanks,

Josh

That organic coolant normally looks dark and yucky like somethings wrong. Maybe top up the oil ir change it, flush the coolant and test it for a bit. If they are mixing it will look real bad. Not out of the ordinary for some hemis to use alot of oil

It's bad. Just did a Tstat in it a few weeks ago and it was still good. Did an oil change about a month ago as well. There was a fair amount of oil in the intake too. Going to dig into it tonight.

I would almost bet it's head gaskets also.

My advice, Get a 6.4 cam and valve springs while your in there and carefully check every lifter, roll it on a clean piece of glass and listen for anything thats not a normal rolling sound and replace the bad ones, even better just buy 16 new ones if you can swing it. Machine the heads to make sure they seal up real good, while they have em tell em to take .020 off, this will give you a smidgen more compression and a tiny bit more lifter pre-load to keep lifter tick at bay as the PRs are just barely long enough, almost not long enough. Throw in a new water pimp while you at it.

What Dave said X2 , but I'll add ...yes get the heads checked it's rare that one of these eagle heads crack...but not impossible.

I was planning on getting the heads gone through. I do not want to do this again. I am assuming the 6.4 stuff won't affect the computer?

Does anyone recommend a gasket kit?

Heads are just about ready to come off. Looks like there was coolant mixing in the oil as well. It had just started spraying on the underside of the valve covers.

The 6.4 stuff helps even with the stock computer, it helps even more if the computer is tuned for it.

The 6.4 SRT cam is over $100 less than the 5.7 cam. The 5.7 springs are a couple hundred cheaper and seem to work ok and have similar spring pressure so I don't know what the difference is but I would get the 6.4 springs if I could swing em. The 5.7 springs do break occasionally after about 150,000 miles thats why I recommend replacing them while you have it apart.

Thanks! Going to look into the cam/springs/lifters. We are keeping this thing forever and I don't wan't to redo this again.

I ripped everything apart. What a mess. I have never pulled apart an engine that has pumped oil into the coolant. There are no obvious signs of failure, at least on the gasket surface. Is there a particular spot that these heads crack or gaskets fail?

Do those things have an oil cooler?

If so thats where I`d be looking.

X2 on the spring, the issue with using the 5.7 spring would be in the higher RPMs over 6200, valve flutter

I have run that cam both ways wit tune and with tune, w/tune slightly better fuel mileage, you can feel it come on strong after 3000/3200 only issue I've had with out the tune was some cold weather start ups, and idling but once it got up to temp it ran just like the stocker cam.


the place that I see the gasket failing the most is the slot where the block feed oil to the head bolt that feeds the rocker gear.

That slot is exactly where I was thinking. Nothing is popping out at me but there is no coolant in the oil except splattered on the top inside of the valve cover. I am assuming this is more of a corrosion issue than a "blown" head gasket.

I talked to the machine shop and they said that hemis have a tendency to drop valve seats. If I remember correctly that was the earlier heads?

Does everyone just reuse stock hardware or should I get studs? I was just going to order stock head gaskets as well.

Buy new head bolts, the stockers are Yield to torque, ARP head bolts are a better long term deal...In my opinion

Machine shop got back to me. Turns out head is cracked. Anyone else ever had this issue?

I have only seen about 50 of them but never a cracked one, but that don't mean it's impossible just rare.

Of course it happens to me.... Probably going to cut in half and see exactly where.

Good excuse to get some ported heads for it.................

Cheaper to buy some apaches or BGEs. On the other hand I don't think more flow is going to help power without big upgrades through the system because the eagle heads already flow so good.

I've read conflicting reports on this but do you have to notch the cylinders with 6.4 heads on a 5.7 or will the valves clear? I thought I saw a build on here where a 6.4 head will clear a 5.7 bore (close but it does) but several "experts" on sone Gen 3 groups on FB howl that they don't. Oh and if the heads are coming off may as well put headers on as well (it's very easy to spend your money lol)

Oh trust me I thought about it. Going to do a valve job and mill them a tad.

A little update. I dropped the new cylinder head off at the machine shop and they showed me the video of the pressure test. The leak is by one of the lower pushrod holes. There is seepage through what looks like the casting grains if that makes any sense. There are no visible cracks.

That makes sense, air pocket in the casting process.

Got this thing back together a week ago. It is a beast! Going to need headers and a tune soon. Something else I noticed is that a one of the lobe on the cam had a "chip" on the top of it where it was wearing. The lifter had some shining spots on it but nothing that had started scoring and it still rolled smoothly. Obviously if I had not have the cylinder head issue with would have gone out at some point....

Does anyone have a real answer why hemis eat lifters/cams? I do realize the needle bearings go but is it a material or production defect? I have done some searching and have come up with earlier production of the mds lifters doing this but there is no definitive answer as far as specific part numbers go (at least I didn't find anything). From what I can tell all of the new mds hemis use the same lifter and they have superseded a fair amount of previous lifter models.

So what cam, heads, milled how much if any... did you end up putting in?


As for the lifter, I'm guessing bean counters had something to do with the lifters falling apart, I never seen a 6.1 or 08 back 5.7 do it, something changed in 09+.

I did exactly what you said. Had to grab another new head (drivers side eagle), 6.4 srt cam and springs ,new lifters and took 20 thousandths off. I used all ARP hardware for the hell of it.

Any idea what the compression is after taking 20 off the heads?

I wanted to have the bad head cut apart to see what the heck happened but there was a $150 core charge so I sent it back.

It amazed me how easy this engine was to work on. Almost makes me want to put one in my Challenger.

So you’re running a stock tune with the 6.4 cam?

side track,

my experience with 6.4 heads on 5.7 blocks....stock 3.917 bore.....too close needs to be notched if the factory bores are just slightly off you can have an issue, , 3.937 bore they'll clear ..but best results notch it, don't need much.

I think it has to do with the VVT cam lobes,
53022064BD (cars) duration intake 258* exhaust 288* / lift intake .472 exhaust .461
53022314AD (trucks)duration intake/exhaust 290* / lift intake .472 exhaust .460Automatic 5.7
186/208 (4 lobes are actually 205 on the exhaust for MDS)
499/493 (4 lobes have 486 lift on the exhaust for MDS)
115LSA
103ICL

Not sure why but I think when the oil is cut to the MDS lifters there not enough residual oil to keep the roller lubed and the aggressive nature of the MDS lobe puts more stress on the roller....so it's a design flaw in my opinion...…..Lifters don't fail on the Non VVT cams.

Yup, for now. Waiting on headers (which are freaking expensive for this thing) before a tune. Runs fine....

That makes sense. It looks like there has been a few iterations of lifters since the intro of MDS. I wonder if they have actually solved the issue with new vehicles.

It is definately NOT because of the MDS, I have done many on 3/4 ton trucks including one I bought in tuscon with a flat cam and drove all the way here (2000 miles) and fixed. I still have that cam laying here, is there a way to prove what it came out of?

The non MDS engine has full pressurized lube to the lifter body all the time

Correct,... you have 2500 NON MDS ? what year is it ?

09. It's the one I put the 6.4 SRT cam in.

Interesting. Where they all 5.7s?

2009 through about 2012 5.7 is what I have seen and as low as 101,000 mileson up to my 2011 with almost 300,000 miles. Never an earlier one, no 6.1, 6.2< or 6.4 either flavor. Anything newer is probably ending up at the dealer so I don't know if it's a continuing issue or if they fixed it yet. I am looking for a decent 1/2 ton 4 door 09+ I can buy cheap and swap in my 6.4.

the issue happens with high idle hours, most common is when Idle hours exceeded 7% of total hours. my youngest stepsister works for AutoAssure warranty company and according to their records 90% of all lifter claims are 5.7s with idle hours between 7% and 9% of total hours usage the other 10 are 6.4s with Idle usage above 5%. The Dodge dealership my nephew works at does 2-3 a month same common thread High idle hours ...my brother is a fleet mechanic for a local Municipality, they do 1-2 pursuit charger week and 1-5 1500 2-3 2500 rams a month, keep in mind that when the engine goes in to ECO mod the computer registers that as idle hours,

Dave that 09 2500 you did , did it have solenoids or plugs?