Known overheat issues 4.7 RAM V8? EDIT FIXED

[volaredon]

Maybe it's a location thing, I don't know, but the impression I get from people around here is that the 4.7 is a total POS.

well, I'm about to find out. I too just bought one. From what I hear (I hope they are right) that after 2008 they did some improvements, my new ride is a 12 which, besides being the next to last year for that engine, they did improve ratings (IF they can be believed) to 9.8:1 CR, 310 HP. If true (and even if it falls short by 60 hp or so) that is most HP in any vehicle I have had. I have seen/heard multiple places, that the newer ones with 16 spark plugs (which is what I got) are supposed to be much better about issues like valve seats not dropping as readily and not so sludge prone as the earlier ones. I got a former Fastenal truck (but there was 2 owners in between
Fastenal and me) Mine is a '12 reg cab 8' bed 2wd. I needed to replace the 99 Dakota which is dissolving before my eyes (never seen a truck deteriorate so bad over a 6 month period) and needed something "new enough" that a bank would help me buy. I don't have that kind of$$$$ sitting around. The truck I got is 1 year removed from being at the cutoff for that to happen, and I DID NOT want a 4 door, with a uselessly short, silly short bed!!!!

 

[volaredon]

That's a chain driven water pump isn't it? Kinda like the infamous 2.7L engine, but maybe not dumping water DIRECTLY into the sump.

nope. the 4.7 isn't like that. I had my fill of 2.7s. If I never see another one, it wouldn't break my heart
Never owned one and never will/ but have worked on plenty of 2,7s.
My Mom had an Intrepid with the 3.2 which was a much better choice.

 

[Dale Davies]

My neighbor bought a 4.7 1/2T Dodge plow truck recently, so no real history. It seems to overheat bad on the highway and I did warn him about plow blockage. They tried a new stat. Anybody familiar with "known" issues with this engine? Is there any tricks to filling them? I have not looked at it, he just called me. Heater works REALLY well he says. Bear in mind it's been COLD here high temps last two weeks in low 20's and teens this week.

I told him to try and figure if it is "really" overheating (feel around heads etc) try to find infra-red thermometer.
He said T stat changed things, I even mentioned maybe the new stat is defective
I can't see a rad blockage as it would seem the heater would block first, but ?? (These heaters have tiny passages)
Likely not a water pump or heater would not work "well"

Ideas?

How many miles on this engine? It is a SOHC POS, aluminium head on a cast block. As aluminium and cast iron expand at different rates, the head moves on the head gasket. The number of miles is not exactly the determining factor in when they will fail. Heating and cooling cycles is the control factor. An engine driven on short trips and allowed to get to ambient again, will have many more heating cycles than an engine driven longer distances. The short trip head gaskets will fail at lower mileage than the long trip gaskets for this reason.
To diagnose head gaskets, when the engine is somewhat cool, remove the rad cap. Bend a short U in a piece of welding rod or coat hanger. Slip that under the vent valve so the cap is not holding pressure. Make sure the rad is full and put the cap back on. Now any combustion gas leaking past the head gaskets will bubble in the overflow bottle after the thermostat opens. Quickly snapping the throttle open will bring much more bubbles if the gaskets are failing.
These engines and their V6 relative are a pain in the butt to work on. Most likely require removal of the timing cover to reset the chain tensioners, one for each side.
I did gaskets on a Jeep 3.7L V6, and cussed like a sailor. They had poured stop leak in and plugged the radiator, so it would overheat in a couple of miles. New radiator and it ran like a top. A month later a guy pulled out in front of her, and it was written off.

 

[67Dart273]

Well guys it turned out to be an "easy fix" as the internet says. The son had replaced the T stat and PUT IT IN BACKWARDS. At some point he had pulled it back apart and turned it around, works fine now. LOL I appreciate all the comments

 

[Dale Davies]

way too heavy. Cast iron everything! These newer motor were all cast aluminum with integrated water and oil pumps, serpentine drive, MPFI, yadda yadda. They couldn't save the Slant either, too small valves too long of a stroke. Bring it back in Aluminum with a redesigned cross flow head, EFI? Its still a straight 6, long and long for all the new transverse mounted platforms. Sometimes you gotta start fresh. Spitfire motor, over 300HP in a NA V6? Try that in a 5.2 with 2 less cylinders and a wonky balance crank.

The General and Ford had to travel that road also. The Pentastar has had some issues, Ford 5.0L mod loses valve seal at 60k to 100k miles. The head warps a bit. Usually just out of warranty, but if you take it to Ford for the misfire on 4 and/or 8, they will replace the heads. Take heads off yourself or a trusted mechanic and have the vavles and seats ground, and good to go. The GM LS has been fairly trouble free. That said, all three could have gotten similar results with a major redesign of the existing heads for emissions and economy. Ford was kind of on the right track with the Exploder/Mountaineer GT40P heads. Improved burn and no reliability issues. Getting headers to clear plug wires was an issue.

 

[rustycowll69]

Well guys it turned out to be an "easy fix" as the internet says. The son had replaced the T stat and PUT IT IN BACKWARDS. At some point he had pulled it back apart and turned it around, works fine now. LOL I appreciate all the comments

I had a somewhat similar experience on an 02 3.5L Intrepid Police. I bought it off an online auction. It was specified to have 60-some thousand miles and an overheating problem, but I took a chance on it, winning the bid at $1600. I drove it 13miles home, no problem, but it would slowly build heat just idling in the driveway. I checked the electric fans, the fan relays. I even pulled all the heat exchangers and cleaned out all the dirt and bugs clogging the fins. As a last resort I pulled the t-stat. It was not oem, so someone had replaced it, and put it in backwards. I bought a genuine mopar t-stat, installed it correctly, and I've put almost 100k more miles on it in the last 14yrs with zero problems. In all fairness to the mechanic who installed the t-stat backwards, it is not an easy R&R. It's a rather inaccessible t-stat location, on the side of the block, directly under the exhaust manifold. Unless you dismantle a lot of surrounding accessories, you have to do it sight-unnseen, mostly by feel.

 

[Dale Davies]

Well guys it turned out to be an "easy fix" as the internet says. The son had replaced the T stat and PUT IT IN BACKWARDS. At some point he had pulled it back apart and turned it around, works fine now. LOL I appreciate all the comments

Great to hear the repair was easy. It should have got hot once and then heat would make it to the thermostat and it would open. At that time it would work as designed. Had a slant overhauled at the hi school I had gone to as I had no place to work on it. The thermostat I had bought would not fit the correct way, so a student installed back asswards. That is how I come on that bit of information.