I have a 2003 Dodge Ram 1500 4.7L. I just purchased the truck not to long ago and decided to go through and do an overall tune up it has been acting a little sluggish, and was getting bad mpg. The truck has 156k on her. First I changed the spark plugs after I had ran a full can of seafoam through a full tank of gas. It didn't give me any issues, and the truck ran better. Next I decided to put half a can of seafoam in the oil, and the rest into the break booster vacume line. The truck smoked like it was supposed to, and then I took her out and drove it hard till it stopped. Here is the problem. When I got home and put the truck in park it died as soon as I took it out of gear. It started back up just fine, and then idled rather pathetically, and died again. The truck runs great better than ever while in drive, but if I take it out of gear It dies instantly, just like someone turned the key off. One thing I have noticed is that if I disconect the break booster vacume line like before, it idles perfectly fine, and when I reconnect it the same bad idling issue resumes. My other thought is that the seafoam did its job dislodged something and gummed up a sensor. Any other thoughts or suggestions would be very helpful thanks!

P.S. I've changed the oil since adding the seafoam to it, and the problem still persists just an FYI.

 

Have you cleaned the throttle body yet?

 

After Seafoaming you need to change the oil and the spark plugs again...

It will also help to clean the Throttle Body if you haven't done that already.

You may have a clog in a vacuum line somewhere too though...?

 

Yeah I should of waited to to put in the new plugs before seafoaming it, but at first I wasn't going to induce it through the vac line and oil. But I had a change in heart and did it anyways. I've change the oil since, and pulled a few plugs they both look just fine. I going clean the TB next as you guys mentioned, and see if it helps it probably needs to be done regaurdless. There could be a clog in the vac line, i'm going to dig into that seems how i'll have it all apart. I'll keep you all updated on what I find out. Others out side the forum have mentioned replacing the TPS, IAC, and/or O2 sensors.

 

Make sure your PCV valve isn't FUBAR. You might have clogged it inadvertently.

 

I guarantee that seafoam knocked a whole bunch of crud loose.

 

I've used Sea Foam in several vehicles. Never had an issue (never changed the plugs either). Hope the PCV valve is still on the oil filler. Dodge buried them in later years. Good luck and keep us posted.

 

Im not big on additives, but seafoam is great stuff. I believe using it in the oil is what eliminated my hemi tick. But with that amout of miles on his truck and running basically a whole can thru it all kinds of crud has gotten knocked loose...ive seen a high mileage GM 6.0 completely stalled out after the owner claimed he dumped half a can into the oil and then proceeded to drive 1000 miles with it in there. Gobs of sludge and all kinds of crap came out of that thing when the drain plug was pulled.

 

So as suggested, I went ahead and started with the cheapest and easiest fix. I took the throttle body apart and cleaned it with CRC Throttle Body Cleaner and an old toothbrush. To my suprise it wasn't very dirty. While I had it apart I decide to disconnect the (IAC) Idle Air Control Sensor to see what kind of shape it was in, and it was all gunked up. I sprayed the CRC on a rag cleaned out the hole it went into, and wiped the sensor down really well. I put the old sensor back in, reconnected the throttle body with a new gasket (only $4), turned the truck on, and she idled great! I drove it around the block parked it in the driveway, and it stayed running strong like normal as I took it in and out of gear. I hope this helps anyone that runs into this problem in the future, and a BIG THANKS to all the members on here for your responses they were much appreciated! CHEERS!!!

 

Good job.

And the CRC is good stuff, that's what I use.