[pdavey]

I am hoping some folks on this forum may have some insight as to what is going on with my truck.

Truck: 2005 Dodge Power Wagon QC 5.7L Hemi - 84,000 miles
Performance Upgrades: Green Cold Air Intake, Gibson Catback Side Swept Exhaust

Issue: Occasionally when coming to a stop at a stop sign or stop light the trucks RPM's (usually between 600-800 @ idle), will drop to about 300-400 and feel like it is going to stall out, but usually it recovers immediately. I have had it stall on me a couple of times though. The computer is not throwing any codes so that has led me to believe it is a fuel system or an air system issue. The truck runs perfectly other then this.

I have taken it to the dealership to figure out what is the issue and so far I have had the Throttle Body replaced (thought was a faulty idle control valve) and I have had the ECM Flashed with an update concerning a TSB that was similar to the problem I have been having, however the problem still persists. The dealership seems to be at a loss and I dont have a lot of confidence they can fix the issue at this point.

I am thinking next step will be to clean the EGR valve, but figured I would throw it out to the collective wisdom of the forum for thoughts.

I really appreciate your help in advance.

 

[crash1369]

yup I think the PCV valve could cause that, it's an auto right?

 

[pdavey]

Yup, it is an automatic. You think the PCV valve could cause those problems? Would it just be a cleaning that would be needed?

 

[crash1369]

if i remember correctly a few people have had similar problems and replacing the pcv solved it. either way it costs what ~$13 so even if it doesn't work is probably cheaper than just driving to the dealer

I don't know about cleaning it, dodge says not to and I figure just encase their pretty cheap might as well get a new one. I belive all you have to do to change it is twist and pull it's under the hemi hat on the left (facing the engine)

 

[04Ram2500Hemi]

Mine stalled on me at 40,000ish miles. It turned out to be carbon on the throttle body. Granted you have had the throttle body replaced, but I'd take a close look at the PCV valve too.

 

[pdavey]

Thanks guys. I will pick up a new PCV valve and also a new EGR gasket set (and clean the EGR) tonight and let you know.

 

[crash1369]

if you want to do the egr also thats fine but I would try the pcv first and determine if that fixes it or not. that way youll know what did it, if ou change both at the same time you wont know what fixed it. if you care

 

[Original Junior]

I have the same issue on mine. It's been like that since 5000 miles or so. Coincidentially, it started around the same time I installed my new muffler and dumped it. I just thought maybe the idle drop while coming to a stop was due to that (I don't know: reduced back pressure; more free flowing; etc.) I guess I never thought about it much but I guess I'll replace the PCV this weekend. Just figured it was semi normal. Never shut down on me so I didn't worry about it.
Anyone have the part#? Thanks

 

[pdavey]

Well I replaced the PCV valve and the problem persists (the PCV valve was pretty gunky though so it was a good replacement). I will try cleaning the EGR next and let the group know. If anyone else has any other ideas, let me know.

Thanks.

 

[crash1369]

huh, I'm a little surprised that has seemed to fix it for everyone else. Ok well let us know how it goes with the egr.

 

[flattire]

My first thought would be throttle body dirty or idle speed control....but those have been replaced.....next thought would be fuel (either going too rich or too lean) would cause temp stalling.....wondering if the o2 sensors are getting "tired" and not responding to the sudden decel when letting off gas and going to brakes.....

Also the throttle position sensor ...TPS....these move with throttle and eventually get worn out where they contact inside.

 

[olsarge]

Low tranny fluid. Causes TC to stay in lockup.

 

[TwinStick]

If nothing else seems to work, I would have the TPS replaced(throttle position sensor). I am also wondering if the back pressure was reduced by the new exhaust enough to cause this ???

 

[pdavey]

Isn't the TPS part of the throttle body in the Hemi? Not sure it is a part that can be replaced on it's own.

UPDATED - Checked the Manual/CD and the 5.7 does not have a separate TPS. It is part of the TB. The diagonstic's section also refers to replacing the whole TB when the TPS fails.

 

[Original Junior]

What all is entailed in removing the hemi hat. My shop manual is an 03 and unfortunately it doesn't give any insight to the hemi. I bought it for my 03 diesel but never look at the gasser stuf until I bought the wagon. The darn manual has every thing for a 5.9 & 4.7 but little on the 5.7. Do I just remove the two bolt and pull? I'm planning on changing the PCV this morning. Thanks

 

[crash1369]

sounds good to me (I haven't done it yet ;D)

 

[pdavey]

it is real easy to remove. Just undo the bolts and the tube going to the oil filler. make sure to unplug the temperature sensor in the front of the box and lift.

While you have it off I suggest installing a cold air intake and leaving the hat off all together. One of the problems with the design of the hemi is the OEM airbox. it is way too restrictive. The hat looks nice, but really doesn't do anything.

 

[pdavey]

No EGR Valve on a 5.7 Hemi HD series truck

Well here is an interesting story. The Manual says that the EGR valve is located on the front of the engine on the right side (left side if you are facing the vehical) right below the side of the first cylinder. When I looked for it last night I couldn't find it, so I thought I would try again in the morning with a bit more light. Well I still couldn't find it, however i found a plate covering the area where it should be. It then dawned on me that our trucks likely do not have EGR valves because they are HD trucks and do not have the same emissions standards. Moral of the story, if you are looking for an EGR valve on a 5.7 Hemi and it is a 2500 Series or Power Wagon, it isn't there

Also I have shot an email off to Gibson on the idea that it could have been the exhaust system per TwinStick. I will let you know what I find out from them. It is certianly a posiblity given that the issue didn't start until after the system was put on.

 

[crash1369]

yeah I was gonna say I didn't think we had one, but I wasn't sure and figured you knew what you were talking about ;D

 

[crash1369]

I would be surprised if it was the exhaust but if you think that could be a cause you could always just try adding a little back pressure and see if that helps, just put something in there to restrict the flow a little.