Replace spark plugs?

[Lilflowww]

hi everyone, I am very new to car maintenance so this could be a very stupid question.

So I am planning for a road trip in August from Chicago to Denver, and I am looking to replace all worn parts on my 15 fpiu. Its a 3.7L v6.
I noticed that the noise comes from spark plugs when idling is kinda annoying because it was very loud when the hood is open, so I am deciding to replace all of them.

Car runs great, there are no significant issues like misfires. However since it already has 155k miles on it and I did not find any spark plug replacements from carfax car maintenance history, and the manual says they should be replaced every 100k miles.

Also I never heard what a good fpiu engine sound, so I just found some dealer walkaround videos and their engines all sound loud, just like mine. Does that mean the noise is not even a thing?

Should I replace them? I am very worried if it gonna break down in the middle of nowhere. Also I already have all required tools and ordered replacements, but I can return them so not a big deal. Thanks!

 

[richey]

hi everyone, I am very new to car maintenance so this could be a very stupid question.

So I am planning for a road trip in August from Chicago to Denver, and I am looking to replace all worn parts on my 15 fpiu. Its a 3.7L v6.
I noticed that the noise comes from spark plugs when idling is kinda annoying because it was very loud when the hood is open, so I am deciding to replace all of them.

Car runs great, there are no significant issues like misfires. However since it already has 155k miles on it and I did not find any spark plug replacements from carfax car maintenance history, and the manual says they should be replaced every 100k miles.

Also I never heard what a good fpiu engine sound, so I just found some dealer walkaround videos and their engines all sound loud, just like mine. Does that mean the noise is not even a thing?

Should I replace them? I am very worried if it gonna break down in the middle of nowhere. Also I already have all required tools and ordered replacements, but I can return them so not a big deal. Thanks!

I am not sure what "noise" you think your sparkplugs are making. I'm willing to bet you are talking about valve chatter which is normal on these engines. I switched my oil to 5W-30 and they quieted down a bit. I have been told that these engines handle 5W-30 just fine but Ford wanted to milk an extra 1-2 mpg out of them so they went to a thinner oil.

As far as changing spark plugs it is a good idea. I would pull one and inspect to see what it looks like. It could be that they were changed before you bought it. Any in-house maintenance would not likely show up on a Car-Fax. The two main issues you may run into doing spark plugs are:

1. The little clips on the ignition coil plugs sometimes go brittle and they break when removing them. Not hard to replace, but it's annoying.

2013 FORD POLICE INTERCEPTOR UTILITY 3.7L V6 Ignition Coil Connector | RockAuto

RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog.

www.rockauto.com

2. The ignition coil boots swell up and get stuck and rip when you try to remove them. You then need to use long needle nose pliers and remove them little piece by piece. It can be a real pain in the neck, especially if it happens to the rear bank since it's harder to see back there. If it does happen you can buy just the coil boots and contact springs and rebuild them yourself. I found that the best way to avoid ripping the boots is buy slightly rotating the coil back and forth until it breaks free from the spark plug. Works about half of the time.

2013 FORD POLICE INTERCEPTOR UTILITY 3.7L V6 Spark Plug / Ignition Coil Boot | RockAuto

RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog.

www.rockauto.com

I did notice a smoother idle and slightly better fuel economy from changing mine, but they were really fouled. The problem with leaving them alone is that if the boots are not already stuck, they will be eventually. If they aren't stuck then it is an easy task, if they start tearing then you'll add an extra hour or two easily.

 

[Lilflowww]

I am not sure what "noise" you think your sparkplugs are making. I'm willing to bet you are talking about valve chatter which is normal on these engines. I switched my oil to 5W-30 and they quieted down a bit. I have been told that these engines handle 5W-30 just fine but Ford wanted to milk an extra 1-2 mpg out of them so they went to a thinner oil.

As far as changing spark plugs it is a good idea. I would pull one and inspect to see what it looks like. It could be that they were changed before you bought it. Any in-house maintenance would not likely show up on a Car-Fax. The two main issues you may run into doing spark plugs are:

1. The little clips on the ignition coil plugs sometimes go brittle and they break when removing them. Not hard to replace, but it's annoying.

2013 FORD POLICE INTERCEPTOR UTILITY 3.7L V6 Ignition Coil Connector | RockAuto

RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog.

www.rockauto.com

2. The ignition coil boots swell up and get stuck and rip when you try to remove them. You then need to use long needle nose pliers and remove them little piece by piece. It can be a real pain in the neck, especially if it happens to the rear bank since it's harder to see back there. If it does happen you can buy just the coil boots and contact springs and rebuild them yourself. I found that the best way to avoid ripping the boots is buy slightly rotating the coil back and forth until it breaks free from the spark plug. Works about half of the time.

2013 FORD POLICE INTERCEPTOR UTILITY 3.7L V6 Spark Plug / Ignition Coil Boot | RockAuto

RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog.

www.rockauto.com

I did notice a smoother idle and slightly better fuel economy from changing mine, but they were really fouled. The problem with leaving them alone is that if the boots are not already stuck, they will be eventually. If they aren't stuck then it is an easy task, if they start tearing then you'll add an extra hour or two easily.

Hi,

Thanks for your reply! I found this very informative and useful. I will take a look at the spark plugs tonight when I reach home. Thanks a lot!

 

[peterk9]

I am not sure what "noise" you think your sparkplugs are making. I'm willing to bet you are talking about valve chatter which is normal on these engines. I switched my oil to 5W-30 and they quieted down a bit. I have been told that these engines handle 5W-30 just fine but Ford wanted to milk an extra 1-2 mpg out of them so they went to a thinner oil.

............................................................................................

5W-30 is the recommended oil.

Peter

 

[richey]

5W-30 is the recommended oil.

Peter

My oil caps disagree.

 

[Lilflowww]

5W-30 is the recommended oil.

Peter

Just checked manual, 5W-30 is recommended for EcoBoost engines and 5W-20 is for other regular engines

 

[Lilflowww]

Alright I came back with the result: I removed one of the spark plugs and found out the gap on the old one is not the same as the new one. The old one is kinda rust but still looks good, so I did not bother replacing anything

 

[J_C]

?? What do you mean gap on old is not same as new? You need a gauge to measure gap and determine how worn they are.

Doesn't the 3.7L need the intake manifold taken off to replace the rear bank of plugs? I'm wondering if this might be a good job to take to a shop to have done, given the context of the topic. You could also ask the shop about the noise. Some noise is normal, but other could be excessive valve or chain noise or something else. In other words, has it gotten louder? My '14 3.5L does not make much noise at all. It has synthetic 5W-20 in it.