[Don47]

NOTE

If you have the 4.0L (R/T) engine use this below LINK

Changing Nitro Plugs 4.0L

If you have the 3.7 engine in your Nitro use this Thread.

I have attempted in separating "Changing Nitro Plugs 3.7 & 4.0L" into two THREADS. One for each engine type, since there are differences mainly the requirement of removing the intake manifold on the 4.0L (R/T) engine to end any confusion. I did not remove the posts concerning the 4.0 engine from the original thread but did mark them in RED.

Hopefully this will help.

The 3.7 liter (226 CID) six-cylinder engine is an 90° single overhead camshaft engine. The cast iron cylinder block is made up of two different components; the first component is the cylinder bore and upper block, the second component is the bedplate that comprises the lower portion of the cylinder block and houses the lower half of the crankshaft main bearings. The cylinders are numbered from front to rear with the left bank being numbered 1, 3, and 5 and the right bank being numbered 2, 4, and 6. The firing order is 1-6-5-4-3-2. The engine serial number is located at the right front side of the engine block.

The 4.0L Liter (244 Cubic Inches) 60° V-6 engine is a single overhead camshaft design with hydraulic lifters and four valves per cylinder The engine does not have provisions for a free wheeling valve train. The cylinders are numbered from front to rear, with the right bank odd numbered, and the left bank even numbered The firing order is 1-2-3-4-5-6. The engine identification number (2) is located on the rear of engine block just below the left cylinder head



I can't locate th spark plugs in my 2007 Nitro to replace them and what plugs are best?

SPECIFICATIONS
SPARK PLUGS

ENGINE PLUG TYPE ELECTRODE GAP

3.7L V-6 ZFR6F - 11G (NGK) 1.1mm (0.043 in.)

4.0L V-6 NGK R - ZFR5LP 13G 1.2mm - 1.35mm (0.048 - 0.053 in.)

 

[rickaren]

I can't locate th spark plugs in my 2007 Nitro to replace them and what plugs are best?

I too have a 2007 Nitro (R/T) and have read they do not need to be replaced till 100,000 miles! Check your Owners Manual.

 

[keonz]

try NGK or Splitfire. they are good.

 

[don1047]

I do not have a Nitro R/T I have a Nitro SLT 3.7 engine and the owners manual and delar says to replace the spark plugs at 30.000 mi.

 

[don1047]

How do I locate and replace them and what plugs should I use.

 

[Cyklopz]

Changing Nitro Plugs 3.7 & 4.0L

I could not find any detailed pictures or instructions for replacing plugs on the Nitro 4.0L but I managed to figure it out. Here are some pics and information that may help others.

Overall list of tools used: Ratchet with 6/3/1" extensions, 8/10mm sockets and plug socket, 13mm open/box wrench, pliers, flashlight, shop towels, minimal cursing.

To replace the plugs you will have to remove the entire intake manifold on top of the engine:

1. Remove the four (4) hoses on the passenger side, one has two bolts holding it in. 8mm socket used for these

2. Remove the four (4) bolts holding the throttle? assembly on the front passenger side of the manifold. 10mm socket used for these

3. Remove the four (4) bolts holding the assembly to the right of the throttle? and disconnect electrical connection. Watch out for the O-ring inside as it will fall out easily. 10mm socket used for these.

4. Remove the two (2) nuts on the drivers side of the manifold that are towards the bottom, move the hanger out of the way and then remove the two (2) copper nut/bolts as well. 13mm box/open wrench used for these.

5. Fully loosen the seven (7) long bolts along the center top of the manifold. The rear most bolt is very tight fit, I used a 1" socket extension for this one as the socket on the ratchet was to short and anything else was to long. 10mm socket used for these.

Pictures listed below. More in part 2.

Cy

 

[Cyklopz]

Changing plugs on 2011 Shock 4.0L 4x4: PT. 2

Continuing from part 1:

6. When all hoses and nuts/bolts are loosened and removed you can carefully remove the intake. You will have to wiggle it around a bit to slip it free and watch the metal hose on the passenger side as it slides into the manifold about 3-4"s (also watch this when mounting the manifold when done).

7. When the manifold is gone it is now very easy to reach the plugs and do the swap. Just disconnect the electrical wires, remove the retaining bolt on the coil and slip the coil out of the well. Then use an extension and plug socket to remove the plugs one by one.

8. Use thread lub and dielectric grease in the boots as desired. Carefully insert the new plugs guarding against cross-threading.

9. Reverse all steps to re-assemble all components.

10. After double checking everything during the rebuild reconnect the negative battery terminal and start motor. Check for leaks or any dash codes/lights. Take for a test drive and enjoy!

It took me quite a while to complete this project as it was all new to me and I had to make a couple of runs to Lowes for additional tools. I'd say it took about 3.5 hours going slowly and having to figure some things out.

Cy

 

[rickaren]

Great Job Again Cyklopz!

You are not changing your plugs already are you? Read they should last 100,000 miles!

 

[Cyklopz]

Rick,

I did but just because I wanted to upgrade to higher performance plugs over stock. The new Bosch seem to be running great so far.

Cy

 

[Ohio Mopar]

I slapped a set of IR Fusion plugs in my 3.7L in October(much easier to change I might add) and it is like getting 2 more cylinders under the hood!!!!

 

[Eugene Onegin]

Cyklops your the Man.

 

[DIDYOMA]

Nice write up on this man, you took time with posting this and made sure it was right. Thanks yo.

 

[jhnhopkins]

Replaced the plugs in my 3.7L at 88,000 miles, gap was about 60thou and worn about half down to the root. The Bosch Platinum plus plugs really make a difference. You do need a 6 foot long extension to get at them tho. They are hidden deep. lol

 

[rtd2]

Another plug question

About to change Plugs in my 3.7l I've seen several users report good results using NGK's Iridium #6441 BUT when I went to autozone and Advanced their computer both listed Bosch's New Iridium #9604 as the plug that fits my Nitro? any thoughts or anyone used this Bosch plug 9604? thanks

 

[dhh3]

The 3.7 is basically the 4.7 with 2 cylinders cut off. I am a member of the Jeep Commander forum and a multitude of members with both the 3.7 and 4.7 have had dubious results using plugs other than the ones recommended by Mopar. Since I never changed the plugs in my Commander in the 5 years I owned it (only drove a little over 36,000 miles), nor did I have my Liberty Renegade with the 3.7 long enough to warrant a plug change, I can only offer what the other members posted. My Nitro is at 6,000 miles now, so a plug change is a while away for me. I would be curious to see what other members on this forum have done.

 

[jhnhopkins]

Spark plugs

I'm running Bosch Platinum Plus in my 3.7L and am very happy with them. Currently at 95,600miles.

 

[dhh3]

This is good to know as I have always been a huge fan of these plugs. How many miles do you have on your Nitro, and how long ago did you change them? Did you notice any performance difference, and did it affect your mileage? Thank you for the reply. While on the Jeep forum, I was never comfortable with the only choice being what the factory recommended. It was like an "inside job"!

 

[jhnhopkins]

Sorry, total 95,600, plugs were changed at 88,000mile, so there's only about 7,600 on the Bosch plugs.

I'm in Canada so know fuel mileage [sic] is 10litres/100km. When I bought the truck with 27,000mile on her it was 10.5litres/100km, so it is better.

Performance improved also, but I put that down to the 0.060"
plug gap in the original plugs. lol.

Ran splitfires in my Cherokee, and liked them too.

 

[dhh3]

Thank you for the reply. Now I know what I am going to do when it is time to change my plugs. I plan on adding the Mopar CAI first. I'm going with the Mopar, only because I do not want to void my new warranty. I'll monitor the results and then go from there.

 

[rtd2]

Great info. thanks for the replies everyone. I think I'm going with the Bosch Platnium plus mainly cause I found them on sale for 2.59 ea. I was just suprised how much the Box stores computers varied. I found a link that has good info. on the plugs that are available for the 3.7l

Sparkplugs.com - Application Search Results