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Discussion Starter · #1 ·
I recently bought a 2001 dodge Dakota for work. When driving it I noticed the temp gauge would get up a bit past halfway figured I’ll check it soon, After 2 weeks the temp shot up into red and the check gauges light came on, coolant was on the floor, I bought and replaced lower coolant hose, thermostat, and the dorman hose (which was the problem) Bled and replaced coolant, turned on fine, after a quick drive around the block, driving around 20mph, I was pulling back in I heard a ‘clank’ sound and check gauges light came back on but I have no leaks. Looked under the hood and found a hole in the driver side valve cover. Is this a common problem (overheating) with these engines? If so how can I prevent it from happing again.
Note I believe car was burning oil or coolant somehow but the fluids had no indication of mixing with one another, just some smoke out of the exhaust when driving but a lot of smoke when stuck in traffic.
Automotive tire Automotive wheel system Gas Auto part Metal

This picture is the driver side valve cover towards the front of the truck.
 

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Discussion Starter · #3 ·
That's an ugly looking wound to the valve cover.
I think that the first thing to do would be to pull it off to see what parts and pieces of your valve train came loose in there.
When the 'check gauges' light came on, out of curiosity, which gauge was it?

As far as preventing the overheat condition:
I'd say regular preventive maintenance on the cooling system. A flush and fill every five years with a new 'stat & cap & s-belt, and periodically going through & replacing all the hoses.

But I also think that if a cooling system has been neglected for a long enough time, damage may have already happened (head gaskets, cracked heads, etc.) that may be beyond preventive maintenance.

I am not saying that nasty looking valve cover is related, but that is the first thing you would need to address.

Also, on edit: which is the "Dorman hose" you are referring to?
This is the hose I’m referring too, I’m not sure if it’s the return line but it carries coolant, above the engine just below the intake/throttle body. May also be called a heater hose I’m not sure. Also, I’ve looked online and some say it could be valve cover gasket that was leaking or the valve covers were put on the opposite side( (not sure how that could happen) causing it to hit the cover and eventually break. but the truck still turns on and idles perfect. As in no weird noises or knocking. I had a mechanic take look (around 9pm) and he said just from hearing it turn on it does not sound very serious, possibly something came loose causing that hole in the cover but not ‘serious’ engine damage, most likely couple hundred dollar repair but shouldn’t be anywhere near the thousands
 

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Discussion Starter · #6 ·
. . . oh, and it just struck me that yours is a 4.7 with overhead cams, meaning that your valve train (under those valve covers) is a bit of a different animal than what I was originally thinking of.
mine is a 4.7L V8 Magnum if that Answers the overhead came question, not too sure about the cams though
 

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Discussion Starter · #7 ·
mine is a 4.7L V8 Magnum if that Answers the overhead came question, not too sure about the cams though
Also I don’t think they ever did any maintenance on the truck because the valve cover looks like it’s been sitting there since 01 but If I am able to repair it myself I plan on updating the car as in wiring, coil packs, spark plugs, covers, etc. I already replaced the idler pulley and I also plan to replace the tensioner too
 

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Discussion Starter · #9 ·
Yeah, the 3.7 and 4.7s have an overhead cam under each valve cover, as opposed to the 3.9, 5.2 and 5.9s which have the more conventional one cam through the center of the engine (underneath) which pushes the push rods up through the heads to open & close the valves via the rocker arms. As I typed earlier, the 4.7/overhead cam set up is a bit of a different animal that I am not familiar with, but I do know that due to the way it operates, it is set up differently underneath the valve covers.

I did a cursory search to try find you a tutorial to explain what all is going on with the valve train on those, and I didn't come up with much, but I am sure if you do some googles, you should find some good pictures. I did find this for you:

Thanks ! I’ll read it and do a bit more research, I’m hoping to take it apart this weekend with some help, I’ll post an update on here about what I find and/or what I did/do to fix the problem , thanks again!
 

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Discussion Starter · #11 ·
That link I sent you is just general info on the 4.7; it wasn't really what I was looking for, but if you are new to that engine you may find it interesting.

Here is a better diagram and there is a thing that you can click on in the diagram to blow it up so you can actually see what it's showing.


It might be a little confusing because the pic is showing both cams in the same picture (meaning the one over the left head AND the one over the right head) so it might make you think it's showing a dual overhead cam setup, but that is not what it is meaning to illustrate. But what you can see is that the cam actually sits on top of the rocker (no push rod) and opens and closes the valves by pushing down on the rockers (as opposed to pushing the push rods up to the rocker arms). From what I read, they were talking about the lobes of the 4.7 cams sitting right on top of "cam followers" which I assume would interface with the rockers, but I am not really seeing the "followers" in the diagram. The diagram also isn't showing the timing chains for each individual cam, and from what I have read previously on that subject, changing them is a complicated job.

That picture of your valve cover damage got me interested, so in the process of looking for a better picture of the 4.7 OHC valve train, I came on a few threads in forums related to the subject of rockers "jumping off" on that engine. So I guess that must be not uncommon. I am not saying that I think a rocker "jumped off" & punched a hole in your valve cover, but the concept does have my interest aroused. I guess that I am thinking that that is NOT what happened, as I would think you would hear some clattering if that was the case.

But anyway, I'll wish you well on this job and I am interested to read your follow up.
Thank you for the info , hopefully it’s not too complicated for me to take on, I normally work on my cars instead of going to a shop but I also know I have my limits, thanks again I’ll update soon !
 

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Discussion Starter · #12 ·
That link I sent you is just general info on the 4.7; it wasn't really what I was looking for, but if you are new to that engine you may find it interesting.

Here is a better diagram and there is a thing that you can click on in the diagram to blow it up so you can actually see what it's showing.


It might be a little confusing because the pic is showing both cams in the same picture (meaning the one over the left head AND the one over the right head) so it might make you think it's showing a dual overhead cam setup, but that is not what it is meaning to illustrate. But what you can see is that the cam actually sits on top of the rocker (no push rod) and opens and closes the valves by pushing down on the rockers (as opposed to pushing the push rods up to the rocker arms). From what I read, they were talking about the lobes of the 4.7 cams sitting right on top of "cam followers" which I assume would interface with the rockers, but I am not really seeing the "followers" in the diagram. The diagram also isn't showing the timing chains for each individual cam, and from what I have read previously on that subject, changing them is a complicated job.

That picture of your valve cover damage got me interested, so in the process of looking for a better picture of the 4.7 OHC valve train, I came on a few threads in forums related to the subject of rockers "jumping off" on that engine. So I guess that must be not uncommon. I am not saying that I think a rocker "jumped off" & punched a hole in your valve cover, but the concept does have my interest aroused. I guess that I am thinking that that is NOT what happened, as I would think you would hear some clattering if that was the case.

But anyway, I'll wish you well on this job and I am interested to read your follow up.
Update : so I woke up Saturday and went to the junkyard with my brother to pull a valve cover off, after doing so I looked inside and took some pics of what it looks like under the valve cover. We took the valve cover back home to my truck and after taking off the valve cover of my truck we saw that a rocker arm fell off towards the front of the engine, BUT it fell off because a valve lifter was stuck in the ‘up’ position. When the cam rotated and the other side of the rocker arm matched the height of the lifter it caused it to loosen up in turn causing it to get picked up by the cam and shooting it towards the valve cover. My cam has minor scratches but no major damage. So today (Sunday) I looked up the prices for junkyard lifters and it’s about $1.50 each lifter, but the junkyard with the truck is a good 40 miles away, so I plan to just buy them in store for around $10, install them (with some coolant as I had to remove coolant lines to take off the valve cover) and I’ll post another update on how things go. I was very suprised on his this engine didn’t have push rods but I remember you mentioning it or reading it in an article you sent, thank again! I’ll post another update soon
 

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Discussion Starter · #14 ·
Good update with good pictures! Thanks!

Yes, the OHC 4.7 is a bit different than most other V-8s. As I typed previously, when I was looking for that last diagram I sent you, I came upon at least a couple of threads on Dodge forums related to a rocker coming off. I would have thought, however, that this would make it run crappy and make some valve train noise, but that presumption does not come from any personal or practical experience. If you do a google using "Dodge 4.7 rocker jumping off" you will find some posts on Dodge forums talking about that subject.

From what I have read, it is changing the timing chains that is real tricky on those engines.
So I went to the parts store and bought the lifters because I didn’t have enough time to get them at the junkyard as my brother had somewhere to be, but what we realized after putting the new lifters and rocker arms back together is that one of the valves got bent, when turning the engine by hand it (the valve) would go down all the way but wouldn’t fully return up, causing the rocker to be loose and that’s what caused this whole problem the first place. After weighing my options on taking it in to get fixed or junking the truck I find it easier and cheaper to do an engine swap with a
Dodge 4.7L Rebuilt Reman Engine Long Block, I’m not sure if it will fit but it would be nice if it did. I still need to do some more research on engines and I also don’t feel like spending another 5k on just an engine alone where as I can use the 5k as a down payment on a car, but i also don’t want a car, I like this truck so I think I’ll be moving forward with a rebuilt engine or a refurbished one. As for now I guess I’ll just need to stick it out a couple weeks/months more till I can figure something out, my brain is still racing around thinking about it all happened and what caused it to get bent in the first place lol if you do come across any more information on this engine or other engines, maybe even some potential candidate engines I’d love to hear from you ! You’ve been a great help, thanks again ! I’ll be posting more updates as I look up more information on the truck and engines but if plans change and I decide to buy another truck I’ll be in touch , this is not goodbye but a talk to you soon !
 

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