It all fell apart. Help

[Zinnmaster]

Long story short. My son just bought a 08 ram 4.7 with 85000 miles. Had it about a month and it all fell apart. I get a call from my son saying the truck died while on the freeway. He said engine light came on truck got hot and was pouring antifreeze from the over flow tank. Got the truck towed home and started diagnosing the problems. Obd reads p0117. Tempature control sensor low voltage. Ok. Also I noticed the water pump bearing was rattling. I was worried he blew a head gasket or cracked the head. From the over heating Checked the oil and it looked clean. Oil change was done when he got the truck. So we replaced the tempature sensor. New water pump. And a new battery. After we got the truck together it started up just fine. We let it run to see if it would over heat again. It did the opposite. The truck really never got hot. Tempature outside was in the mid 30s. So I figured the thermostat is stuck open. Replaced thermostat and new coolant. Put truck back together again and went to start it. Now it will start for a second then die. Won't run, rough idel if it does run for a few seconds. I start it and give it has and it misfires until 3000 rpm and the roughness goes away. Foot of gas pedal rough idle the dies again. And the red light comes on dash. The electric throttle control light stays on. New engine light. We scan it now reads p0300. Multiple cylinder misfire. And heavy white smoke from exhaust. So now I'm lost. I think we have a bad head and I stopped throwing money at it till we know what's wrong.

Any one wanna confirm my diagnossis before it gets towed to a mechanic?

 

[Zinnmaster]

Oh forgot to mention it has good oil pressure. Have not done a compression check. However it doesn't matter on the compression because if it is low it's still going to a mechanic.

 

[MADDOG]

Before you take it to a dealer or shop I'd suggest you do 3 things:

1. Clean the throttle body.
2. Replace the EGR valve.
3. "Burp" the air from the cooling system.

 

[Zinnmaster]

Throttle body cleaned. But can't really burp the coolant because truck will not run long enough to get warm and cycle coolant. Unless there is another way to do it. I see the EGR valve is cheap. And I will replace it. But shouldn't it throw a code?
I'm really trying to understand how this truck fell apart so fast.

 

[Redtruck-VA]

I don't know 4.7 engine but I have seen low temp indication from not circulating water across the sensor bulb. The cooling system might have been air lock from the initial work and over heated when started. I would take a look at the spark plugs for signs of being overly hot.

 

[Mikecollins]

Where did you get your sensor apperently cheaper sensors are hit and miss for mopar dont know why just see everybody saying they are crap and wont read correctly. And the coolant temp sensor on this generatio when bad tells the pcm that coolant is 40 below and it dumps tons of fuel to warm up faster.

 

[Demon-HeMi]

heavy white smoke from the exhaust, you blew the head gasket and more than likely warped at least one head, the 3.7 and 4.7 motors are known for warping heads on even a slight overheating, multiple misfire just means the coolant is getting into multiple cylinders...

been down this road before with a 4.7, sucks really bad

 

[Demon-HeMi]

this was my 03, my head gasket failed in just one cylinder and this was the smoke i was getting...


when i drove it and got up over an idle it would smoke out the street, it sucks and i hate that this happened to you, especially since you just got the truck, but at the very least you are going to need new head gaskets...

take it to a good shop and have them pull the motor apart and check the heads and see if they are warped and can be saved

 

[Karlsweg]

Head gasket and water is going into the cyLinder causing a missfire.