I have a 4.7 liter v8 Dakota. It has been to the shop twice now for overheating and no heat coming from the heater. The first time the thermostat was sticking shut. A couple days after the repairs, it was overheating with no heat coming from the heater again. They said the new thermostat was sticking shut as well, and that the heater core was plugged. It has been flushed and a new thermostat was put in again.

The truck is overheating AGAIN after a few days. The temperature needle comes just short of the red line. The heater is still working fine, though. The reservoir is overflowing and there are bubbles coming up through the coolant. I have been told that there would be leaking from the pump if the pump went out. There is no leaking. I also have been told that if it is a bad head gasket, the coolant would be changing color. However, the coolant is still green. What the hell could be the problem?

 

Sorry Bad news you have a blown head gasket everything you list says yes.

The 4.7 is an engine you should never overheat its a fact

The cooling system on a 4.7 should be a priority and maintained every year

 

It does sound like a blown head gasket. Coolant color does not mean there isn't a leak.

An exhaust gas sniffer can be put near the filler neck to detect combustion gases. There are also kits that change color if exhaust products are detected.

Unfortunately pulling the heads can be difficult on the 4.7.

 

Yea, when I open the bleeder just a little to let the air bubbles out, it never stops bubbling. Air is definitely getting forced into the system. What kind of cost would the replacement head gasket incur in the 4.7L v8? It is a high mileage truck at 229k miles, so I'm wondering if it would even be worth it. Fortunately, the second trip into the shop to get the heater core flushed was free since it was under their warranty from the first trip in.

 

Prices vary considerably.

Is it just the head gasket or did the head itself warp from overheating? Which bank? You might be able to tell by pulling the spark plugs - sometimes they are "steam" cleaned by a head gasket leak.

How's the rest of the truck? Can you do this yourself? The worst part is setting the the valve timing.

If you do decide to do it replace the timing set while you're in there. They have a 250k inspection interval - not replacement but inspection and you're getting close.

 

Just my opinion

I say at that mileage an engine swap with a rebuilt may be your best bet.

Still not cheap call around is the only way to see what it would cost you.

The 4.7 is a solid engine it just doesn't like getting overheated

I will ad one more thing the 4.7 needs a quality oil and regular oil changes if you do that it will last you many years.

 

I don't have the proper tools or expertise to do the replacement myself. The rest of the truck is fine, though. New spark plugs, new fuel injectors, new ignition coils, new battery, starter is solid and fires right up in the coldest weather, new fuel pump, new brakes, new exhaust, four wheel drive works great. There's rust on the body, but that's what one would expect after nearly 15 years in Wisconsin. Interior is great. It just seems that the mileage has taken its toll on the engine itself and the cooling system. I have had this truck for two years, now.

 

Get a couple of quotes before you do anything.