05 Ram 4.7L overheated, low compression bank 1...

[xjfish]

Overheated due to being ran low on coolant, waterpump leak. No coolant in oil, no oil in coolant, no coolant in exhaust or any obvious air bubbles in coolant - does not overheat with coolant in it. Runs terrible and has no power. Someone else previously threw a MAP sensor and 02 sensor at this thing. Found low compression (10-60psi) on all driver's side cylinders. #7 (driver's rearmost) being the least compression. Pulled valve cover and found both intake and exhaust rocker arms had puked out and were laying in the head, minimal damage to camshaft. 1-3-5 rocker arms and lash adjusters look fine. Thats as far as I've got inspecting this thing for today.

Has anyone ever seen one of these piles jump timing on one head before (spun cam gear perhaps)? Thoughts?

[Notch]

Tensioners seem like a common issue on 4.7s. They have 3 timing chains and they suck to time. Did you do a hydrocarbon test when you had it running? These engines are notorious for being junk any time they get overheated. I would just price out an engine at the point you're at, but thats just my opinion. If I remember right, engine labor isn't much more than head job labor.

[KrisR]

Send a pm to Turbo302. He has experience with these.

[Turbo302]

Good engine if maintained and not extremely overheated. Couple things could have happened. Have you reinstalled the rockers yet? Take a look and see if the installed valve height looks consistent across all cyl's. What generally happens is when these things get hot, the valve seats drop and then the rocker clearance opens way up and kicks out the rockers. You may have got lucky and had the valves start to seize in the guides and thus were sticking and then kicked the rockers out as well.

In any case, reinstall the rockers and give it a shot. If the valvetrain is super noisy afterward, the seats probably dropped and the valve clearance to rocker is too much. I did have one that sheared the keyway on one cam, but that was after the seats dropped and locked that cam up. If seats dropped, it will need the head reworked or a HEMI swap!

If the 4.7 in my 01' Dakota ever pukes, I am definitely doing the HEMI swap with a cam upgrade. It would be a little sleeper with 400whp!

[Fernanernie]

Tensioners seem like a common issue on 4.7s. They have 3 timing chains and they suck to time. Did you do a hydrocarbon test when you had it running? These engines are notorious for being junk any time they get overheated. I would just price out an engine at the point you're at, but thats just my opinion. If I remember right, engine labor isn't much more than head job labor.

So.......




















Turbo LS swap?

[xjfish]

Thanks for the replies. Turbo, your post is especially helpful, thanks! I have not reinstalled the rockers yet. I will check valve stem height. I was not even sure if the cam was keyed. I have more experience with timing 4.0L Fords and the like... I'm still concerned with the low compression across the board for that bank. This is not my truck, might be kinda hard to sell this guy on a HEMI swap, let alone a 10,000hr turbo LS swap. Truck as 130K on it and is in nice shape otherwise, guy wants to fix existing engine if possible. I'll dig into this thing more tomorrow if I have time. Mostly, I just enjoy Shop Talk discussion from time to time.

I just talked to a regular customer with an 01 4.7L Dakota, has 190K+ maintained miles on the clock and still runs like a raped ape, he loves it. I also have a longblock (with bad rod-knock) sitting next to my tool box out of a heep with 160k. Opted to swap a used engine in that one.

[I Tried]

Check the head around the lifter. I had one do the same thing and it cracked the head around the lifter.


The shitty Mopar water pumps are going to give those of us that fix this stuff tons of work!!! I put a 3.7 in 2 weeks ago and have a 4.7 with the same issue you have all because of a water pump failure.

[I Tried]

Check the head around the lifter. I had one do the same thing and it cracked the head around the lifter.


The shitty Mopar water pumps are going to give those of us that fix this stuff tons of work!!! I put a 3.7 in 2 weeks ago and have a 4.7 with the same issue you have all because of a water pump failure.

[Notch]

Check the head around the lifter. I had one do the same thing and it cracked the head around the lifter.


The shitty Mopar water pumps are going to give those of us that fix this stuff tons of work!!! I put a 3.7 in 2 weeks ago and have a 4.7 with the same issue you have all because of a water pump failure.

Curse of the Chrysler .7 engines.

[Paul Revere]

My 4.7 has 200,8xx miles on it, runs great. However the transmission is giving me issues, goes into limp mode only when warmed up and only when you slow down below 20-15 mph.

[xjfish]

Curse of the Chrysler .7 engines.

I tried: I will take a closer look at that head for cracks. Busy with another head job on a Mercedes and didn't have time to touch this truck today.

I went through the engine in a 2.7L Concorde rental vehicle at my last place of employment. When I got to this thing there were huge chucks of timing chain guides in the pan, tensioners were shot, etc. By some miracle the thing ran smooth when I was done and had over 320K on the car last I saw. I replaced many other stupid parts on the car during a few year period but the car did have the original transmission, which somehow worked flawlessly.

Mr. Revere: Any Transmission DTCs?

[Paul Revere]

Just a P0700 thus far. Which from what I can tell is a generic code that needs to be further diagnosed.

[xjfish]

I did have one that sheared the keyway on one cam, but that was after the seats dropped and locked that cam up. If seats dropped, it will need the head reworked or a HEMI swap!

This seems to be exactly what happened, had time to dig into this today. Found keyway on drivers cam in two pieces. Tension on the cam nut still allowed the sprocket/cam to turn, but it had slipped out of time. That head is coming off for sure, probably both.

[sinSStr]

My 4.7 has 200,8xx miles on it, runs great. However the transmission is giving me issues, goes into limp mode only when warmed up and only when you slow down below 20-15 mph.

A prequel to Speed? "Twenty, stay above twenty! There's a bomb on this Jeep. If we slow down, it'll explode."

[Notch]

This seems to be exactly what happened, had time to dig into this today. Found keyway on drivers cam in two pieces. Tension on the cam nut still allowed the sprocket/cam to turn, but it had slipped out of time. That head is coming off for sure, probably both.

Seems like another .7 issue considering its common for the Hemis to do the same thing.