Fuel economy questions?

[Hagar1]

I've had far too many vehicles that were hard to do plugs on. The worst I owned was a '99 S-series Jimmy with the 4.3, the center plug on the driver's side (#3 IIRC) was almost impossible to get at because the steering shaft was about 3/4" off the boot for the plug. Had to slide a spark plug socket on it, then use an offset wrench to get it out...all through the fender well because that was the easiest way to get to it.

I guess you never changed plugs on a Monza with a V8? Had to get some of the right rear plugs from underneath. Can't remember if it was the monza or the Chevy van that required taking the engine mount off to get a couple of plugs out.

 

[HangmanNY]

Can any of you guys tell me the torque specs for the NGK laser iridium spark plugs in the 5.7l Hemi?

I was trying to find it, but I thought one of the guys suggested also changing the coil boots over the plugs?
I’m about 125,000 miles on the truck. Is that technically necessary or not?

I understand I’m supposed to use a dab of a dialect Electric grease, where the coil boots go over the plug.

Thanks.

 

[2003F350]

Can any of you guys tell me the torque specs for the NGK laser iridium spark plugs in the 5.7l Hemi?

I was trying to find it, but I thought one of the guys suggested also changing the coil boots over the plugs?
I’m about 125,000 miles on the truck. Is that technically necessary or not?

I understand I’m supposed to use a dab of a dialect Electric grease, where the coil boots go over the plug.

Thanks.

If the coil boots look good and aren't starting to crack, I'd leave them alone. If one or more are looking shoddy, then it's worth it to replace them all.

As for the torque specs, I don't know the exact number. 'Tight' is what I've always gone with on spark plugs. About 1/4 ugga, no duggas.

 

[2003F350]

I guess you never changed plugs on a Monza with a V8? Had to get some of the right rear plugs from underneath. Can't remember if it was the monza or the Chevy van that required taking the engine mount off to get a couple of plugs out.

I didn't, but getting at plugs from underneath wasn't anything new to me - did it on a couple of different vehicles, usually with headers. I thought we were sharing horror stories.

Because I had a 3800 SII SC in my '98 Grand Prix GTP. To do the rear plugs, had to remove the 'dog bones' (front engine mounts) to rock the engine forward to make it easier to access the rear plugs. My evidently 'larger than average' forearms prevented me from being able to reach them otherwise.

 

[Hardracer]

If the coil boots look good and aren't starting to crack, I'd leave them alone. If one or more are looking shoddy, then it's worth it to replace them all.

As for the torque specs, I don't know the exact number. 'Tight' is what I've always gone with on spark plugs. About 1/4 ugga, no duggas.

I agree...usually bout a 1/4 turn more after seating.

 

[09SilverRam]

I've had far too many vehicles that were hard to do plugs on. The worst I owned was a '99 S-series Jimmy with the 4.3, the center plug on the driver's side (#3 IIRC) was almost impossible to get at because the steering shaft was about 3/4" off the boot for the plug. Had to slide a spark plug socket on it, then use an offset wrench to get it out...all through the fender well because that was the easiest way to get to it.

Same. I had an olds bravada and hated the plugs on that thing.

 

[Wild one]

The worst ones i ever did plugs on were the early Mustangs with either a 390 or 428 in them,if you ever run into an early big block Mustang with holes torched in the inner fenders,you'll know why,lol. The next worst ones to do were the mid 70's Monza's with a 305 or 350,the back plugs on my supercharged 3.8 Buick are a bit of a pain to do to. I've never thought the plugs on the trucks were that bad to do,but i'll agree the worst ones were the back passenger side ones,the drivers side aren't bad if you have the magnetic swivel socket and a short 1" or 1.5" extension.
When you have the coils off,pull the boots and check the springs and contact point under the springs over close for corrosion,i usually wire brush the springs clean,and stretch them out about a 1/4" and use my dremel with one of these brushes to clean the contact point in the coil tower.If the springs are badly corroded you can buy new boots with springs from Rock Auto

443-02 Cleaning & Polishing Brushes | Dremel

High quality Cleaning & Polishing Brushes 443-02 for your project. ✓durable ✓highest safety standard ✓perfect results. Find out more!

www.dremel.com

https://www.amazon.com/Dremel-Accessory-Cleaning-Removing-Materials/dp/B0035PVRSG?th=1

https://www.amazon.ca/Dremel-Accessory-Cleaning-Removing-Materials/dp/B0035PVRSG?th=1

 

[HangmanNY]

I watched a good video on the throttle body removal and cleaning. I plan on doing that as well as replacing the spark plugs with the NGK laser iridium plugs.

I am at @ 126,000 miles now. If I’m going to remove everything to do the plugs then I may consider changing the coils (for peace of mind). Are there any better grade coil sets out there? Or is it strictly Mopar? Thanks for any helpful advice on this?

 

[Hardracer]

From what I've read from the guys here they pretty much said theres no reason to change a coil unless there bad for some reason(cracked boots, maybe something like that)....I cant remember if they said their good to a higher horsepower or rpm though.maybe both dont know..I'm sure someone will reiterate it.
I asked this before when I went to the iridium plug..my earlier truck year didnt come with the iridium plug and I switched to it.i ain't changing plugs ever again.

 

[Wild one]

I watched a good video on the throttle body removal and cleaning. I plan on doing that as well as replacing the spark plugs with the NGK laser iridium plugs.

I am at @ 126,000 miles now. If I’m going to remove everything to do the plugs then I may consider changing the coils (for peace of mind). Are there any better grade coil sets out there? Or is it strictly Mopar? Thanks for any helpful advice on this?

As Hardracer says,if you don't have any misfiring issues,leave the coils alone,you can clean up the springs in the boots,and the contact point under the springs ,or if they're badly corroded you can replace the boots and springs with new ones from Rock Auto.
The boots just pull /pop off with a twist,and the springs will slide out of the boots.
I like to stretch the springs out about a 1/4" .
The stock coils are superior to the majority of aftermarket coils,and are good to well in excess of a 1,000 hp.
With all the gubbermint controls,the OEM coils have been pretty well perfected

I use these brushes in a Dremel to clean up the contact point in the coil tower

Amazon.com

More Information for NGK 58969

 

[Hagar1]

I didn't, but getting at plugs from underneath wasn't anything new to me - did it on a couple of different vehicles, usually with headers. I thought we were sharing horror stories.

Because I had a 3800 SII SC in my '98 Grand Prix GTP. To do the rear plugs, had to remove the 'dog bones' (front engine mounts) to rock the engine forward to make it easier to access the rear plugs. My evidently 'larger than average' forearms prevented me from being able to reach them otherwise.

Doing the rear plugs on a 2003 Dodge Caravan was not something I would want to do every day.

 

[Sherman Bird]

Fellas,

I have a 2015 ram bighorn with a 5.7 L hemi. We have been towing a small 5 x 10 enclosed utility trailer for the past couple of years. we have made numerous trips between Long Island and the West Coast of Florida.

I always have this thing switched to “tow/haul” mode. And whenever we are trailing, I’m only using premium fuel.

For some reason, we are averaging 13.5 miles per gallon for the first 2/3 of the journey. Then the last 350 miles or thereabouts, the fuel economy starts crashing. And it doesn’t matter which direction we are driving. By the time we get to Florida or Long Island it winds up averaging around 12.1 miles per gallon to 12.3 miles per gallon.
By the way I have routinely changed the transmission fluid and have the new PPE pan, I have changed the transfer case fluids, front and rear differential fluids. I am using the “ high-performance lubricants” motor oil for the past 20,000 or so. And I have routinely changed the air filter. The only thing I haven’t changed so far all the spark plugs. And I’m about 125,000 miles on the truck.

And I can’t figure out why fuel economy seems to be crashing for the last 350 miles of the journey. Once again, it doesn’t matter which direction we are going. It will average 13.5 miles per gallon for most of the journey. Then when we get to our destinations, it’s somewhere around 12 miles per gallon to 12.3 miles per gallon.

I’m looking for explanations on why this could be happening?

Thanks!

 

[Hagar1]

The worst ones i ever did plugs on were the early Mustangs with either a 390 or 428 in them,if you ever run into an early big block Mustang with holes torched in the inner fenders,you'll know why,lol. The next worst ones to do were the mid 70's Monza's with a 305 or 350,the back plugs on my supercharged 3.8 Buick are a bit of a pain to do to. I've never thought the plugs on the trucks were that bad to do,but i'll agree the worst ones were the back passenger side ones,the drivers side aren't bad if you have the magnetic swivel socket and a short 1" or 1.5" extension.
When you have the coils off,pull the boots and check the springs and contact point under the springs over close for corrosion,i usually wire brush the springs clean,and stretch them out about a 1/4" and use my dremel with one of these brushes to clean the contact point in the coil tower.If the springs are badly corroded you can buy new boots with springs from Rock Auto

443-02 Cleaning & Polishing Brushes | Dremel

High quality Cleaning & Polishing Brushes 443-02 for your project. ✓durable ✓highest safety standard ✓perfect results. Find out more!

www.dremel.com

https://www.amazon.com/Dremel-Accessory-Cleaning-Removing-Materials/dp/B0035PVRSG?th=1

https://www.amazon.ca/Dremel-Accessory-Cleaning-Removing-Materials/dp/B0035PVRSG?th=1

Yes, those old Mustangs with the big engines we not much fun, even less fun when the engine was hot. After we have spent some time in this trade, we all can relate to some pretty ugly stories.

 

[Sherman Bird]

Doing the rear plugs on a 2003 Dodge Caravan was not something I would want to do every day.

Try replacing the driver's side spark plugs on a 70's V-8 Monza! HOO! BOY!

 

[turkeybird56]

NGK is a premium manufacturer and supplier of Original Equipment parts to several major auto manufacturers, numerous industrial manufacturers and small engine makers. If you look up your vehicle on NGK's application guide, trust the part they say "meets or exceeds OEM". They know what they're doing and are top quality. As mentioned above, source them from a reputable vendor. Ebay and Amazon are known for having knock-offs floating around. I personally use RockAuto as they are a no-BS vendor and handle their business quickly. Usually the best prices every time, but not always. Also, if you don't have a quality gap check tool, purchase one. Don't use the Mickey Mouse "coin style" gauge. Use a quality feeler gauge type (calibrated wire loops) and learn how to properly adjust them, should they need adjusted. Modern plugs are very easy to damage if mishandled or attempting to improperly gap. Don't trust the verbiage of "gapped from the factory" or "pre-gapped". Always, ALWAYS check gap on new plugs, right out of the box. Every time, always. Find and use the torque spec for your plugs as well. Over-tightening plugs is bad.-

SERIOUSLY """DITTO""" to above.

 

[turkeybird56]

Try replacing the driver's side spark plugs on a 70's V-8 Monza! HOO! BOY!

Wasn't the Monza one of those Chevy dream boats where U had to lift the motor??? I remember one of them style vehicles U had to, just not the model.

 

[Sherman Bird]

Wasn't the Monza one of those Chevy dream boats where U had to lift the motor??? I remember one of them style vehicles U had to, just not the model.

You had to remove the steering column AND jack up the engine! Brilliant, eh?!

 

[turkeybird56]

You had to remove the steering column AND jack up the engine! Brilliant, eh?!

So I did remember the monstrosity. I had an X car in 82 one of them front wheel drive Citations. Nothing special there.

 

[Sherman Bird]

So I did remember the monstrosity. I had an X car in 82 one of them front wheel drive Citations. Nothing special there.

I was in a Chevy Dealer. We had a VERY RARE 350 powered Spyder Monza with the hood decal of a Tarantula! ALA the Firebird decals. I Really cussed over those spark plugs!

 

[HangmanNY]

Spark plug gap tools. It’s been a long time since I looked at spark plug, gapping tools. Someone said to avoid the coin type ones. Well, now I’m seeing all different different kinds of spark, plug gapping tools. There’s the round one with the metal rings. Now there’s all other kinds of gapping tools.

Any advice or recommendations?