[Dre]

I have a '07 Dodge Nitro. My engine light came on and it started to idle as if it was going to cut off. The o ly code that came up was the number two fuel injector. Replaced it along with water pump, idling pulley, serpentine belt, and plugs. It ran fine for two days and the problem is back again. Same rough idling and engine light on. Reading no codes found and no pending codes.

 

[Scar0]

If you have a CEL there is a code. It's just a matter of finding it.
How many miles? When were the plugs changed? What plugs are in it?

 

[Dre]

130k , Champion Double Platinum plugs, changed two weeks ago.

 

[Scar0]

I see you have an SLT. Usually that means you have a 3.7.
Platinum plugs in a 3.7 cause nothing but problems (misfires, burnt up coil packs, poor mileage, etc).
Get them out of there ASAP and replace them with NGK ZFR6F-11G (or equivalent)Gap 0.043”.
3.7 requires plugs changed every 30K.

 

[Dre]

Wow! Ok. I had no idea that would be a problem. I'll replace them ASAP. I've been changing them every 25-30k. Same plugs. Again I truly appreciate the time and effort you've put into this matter.

 

[Dre]

You are correct. . 3.7 v6

 

[Scar0]

Your welcome.
Back a long while ago we had several members with 3.7 using platinum plugs, with problems. So the question came up "why cheap plugs are better for the 3.7?". As it turned out one of our members here knew someone who worked for the company that did the R-n-D for Dodge and the 3.7 engine plugs. Lucky for us... Anyway, they responded with, after lots of testing they simply work the best with the entire combustion system used in the 3.7. Now we know.

One of the side affects of platinum plugs in the 3.7 is excessive carbon buildup in the intake and EGR valve. So you may need to use a fuel additive to clean the injectors, as well as inducing a cleaner into the brake booster vacuum hose to clean out the inside of the intake. Also check the throttle body for buildup. It may need to be cleaned as well. Hopefully the above will help to clean out the EGR. If not, then you may have to pull it and either give it a good cleaning, or simply replace it.

 

[Dre]

On start up...runs great...once it reaches normal operating temperature, the rough idling starts and engine light comes on... AGAIN....So far I've changed water pump, idling pulley, serpentine belt, and recently I've changed the plugs (THANKS FOR THE INFO SCAR). I removed the platinum plugs that were suggested by a mechanic. Not sure where the EGR valve is located but going to try cleaning, or, replacing it next.

 

[Scar0]

Can you get a code for us?
That would help a lot. Right now we are kinda guessing...
When you did the water pump, did you also replace the thermostat?

 

[Dre]

Dodge couldn't get any codes. ..don't understand why. They only told me..."It happens" WHAT?!?! So I basically paid $100 for that life changing wisdom. I now have 20/20 vision again, ran a marathon, found $1000 in my pant pocket while doing laundry. .."Thanks Dodge" lifes great. Thank goodness for you and the others on this forum. They were supposedly checked all that and said everything else is working fine.

 

[Scar0]

Only way they would not get a code is if you disconnected the battery before you went in, and the CEL did not come on during the trip there...
Anyway, EGR is on the drivers side, rear of the cylinder head.

No, or a stuck thermostat could also cause your symptoms, because the temp never comes up enough to "close loop" the system. This should also set a code, however.

How does the oil and coolant levels look? Any coolant in the oil, or visa versa?

 

[Blue ram]

I assume you have tried a injector cleaner fuel additive. (Sea foam, or similar)

 

[Dre]

Sea foam cleaner. CEL was on at Dodge. Oil and coolant fine.

 

[Scar0]

 

[Blue ram]

Frustrating to say the least

 

[Dre]

I would try to clean the throttle body myself, but I may screw it up even more. I was told I could spray throttle body cleaner through the air intake as well. Didn't sound right so I wanted to find out. Yes/No

 

[Scar0]

You can remove the air intake tube from the TB and wipe it out first. (Use your finger to open the throttle valve.)
Then you can start the rig and use a TB cleaner and spray it into the TB. It may temporarily puff white smoke out the exhaust while doing this(Normal). If you use to much it can cause the engine to die. No biggie, just restart it.
Don't pour a liquid directly into the TB!
You can also disconnect the vacuum hose from the brake booster side and induce cleaner into it, to clean the manifold. Pinch off the hose in between sprays to prevent it from running to lean.

 

[Dre]

@Scar0...thanks for the info. Just tried all that. It does run much better.

 

[Ivoshkov]

I am having the exact problem with my 08 (only the code says #1 fuel injector) it will start and run great while cold but on restart after it warms up it runs horrible.

 

[Dre]

Frustrating. . . I know. It finally just stopped running after every possible thing was tried. I'm not going to put any more money into it.