Stalling engine after driving short distance

JASON ESTES

MEMBER
1998 DODGE RAM
5.2L
V8
4WD
AUTOMATIC
176,700 MILES

Purchased the truck listed above 1500 and immediately noticed my heater core had a leak because my windows were fogging up. Replaced it with the one from my broke-down 1997 Ram 2500 that heated like a champ. Heater blows cold, temperature gauge stays at 130. Replaced thermostat same problem. Replaced coolant temperature sensor same problem. No more dogged windows but won't get hot.
Check engine light came on and have a code for misfire on #5. Engine starts dying when I stop at intersections after a few blocks. So I replace plugs, wires, distributor cap and rotor. Check engine light off but still dying once warmed up, (gauge still not riding, heater still not heating).
Oil pressure high. Exhaust leak between o2 sensors. Possible oil in coolant. Can anyone tell me what is the problem here? Cracked head? Blown gasket? Stuck valves? And what's up with the darn heater and gauge?

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1 Reply

JACOBANDNICKOLAS

MECHANIC
109,758 POSTS

Hi,

You have a number of different issues happening. If you have coolant mixing with the engine oil, either you have a bad head gasket or something is cracked.

Lets start with that concern since it is the biggest issue. Take a look through this link:

https://www.2carpros.com/articles/head-gasket-blown-test

Now for the other issues. Do both heater core hoses get hot when the engine is warn and the heater is on? If they do, then the issue is related to what is called a blend air door. If you look at pic 1, I attached a pic of the door. There is an actuator to move the door in different directions when you change temp. On this vehicle, it is controlled by engine vacuum. If there is no vacuum, the actuator won't turn the door for heat. Also, if there is a vacuum leak, it can cause the engine to stall when at idle Take a look through these links and let me know if any of them help.

https://www.2carpros.com/articles/car-heater-not-working

https://www.2carpros.com/articles/replace-blend-door-motor

Keep in mind, some actuators are electric and others, like yours, can be vacuum or cable controlled. The vacuum reservoir is mounted in the passenger side cowl plenum area, under the cowl plenum cover/grille panel. The cowl plenum cover/grille panel must be removed from the vehicle to access the vacuum reservoir for service. That is where I would start checking for vacuum leaks. Also, here is a link that explains how to find one:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

If you look on the back of the control panel, you may see a cable. See pic 2. If the cable is there, make sure it is properly attached. If you follow the cable (if it is of a cable design) it will lead you to the temp door. At that point, confirm it moves when you change temperatures.

Okay, I see the oil pressure above. It is still within the safe range, so it really isn't that much of a concern at this time. The exhaust leak is a different issue. A leak before an oxygen sensor can allow unmetered air to make its way to the sensor. In that case, the computer sees the system as running lean and will try to compensate by adding fuel. That can also be a partial cause of the stall.

If the check engine light is on, I recommend having the computer scanned to see what codes are stored. If possible, let me know what you find.

The coolant / oil mixing is a much bigger concern, but I wanted to give some direction on these others.

Let me know if this helps or if you have other questions.

Take care,
Joe

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