Yes; Especially since the factory-installed metal tag that's bolted onto on the diff. cover says "Use 75w140 Synthetic Gear Lube ONLY".
Improved gas mileage with new spark plugs & wires???
- Thread starter wavinwayne
- Start date
- Status
I don't think 75w90 Syn. would hurt anything in this particular Expy. We don't tow with it. It is used only to haul my wife & daughter to & from school. BUT, I'm not willing to chance it.
Sweet!quote:
Originally posted by wavinwayne:
BlazerLT,
I replaced the PCV valve about 4k miles ago, so it doesn't need to be replaced.
Ok, If you want to get the most mileage out of that big truck, you might want to change your transfer case and differentials to synthetic.
My observations after the plugs/wires replacement:
The Expy runs EXACTLY like it did before. No noticeable improvements whatsoever. This is not really a bad thing, though. It seemed to run just fine before I changed the plugs/wires.
I just thought that with 114k miles on the original plugs/wires, I would feel SOME improvement in throttle response, acceleration, etc......NOPE.
FWIW, the specified gap for the plugs is .054". The center electrodes on the plugs I removed were burned down to approx. .075". This is one reason I expected to feel some noticeable improvement in power, etc.
Oh well, nothing ventured, nothing gained. Maybe the gas mileage will improve a little with new plugs/wires.
Last thing....If you have an Expedition 4.6L or 5.4L: Unless you REALLY, REALLY enjoy working on it, pay to have this particular job done for you. For me, it was a MAJOR PITB. If I'd had an extra $200 laying around, I definitely wouldn't have done this job myself.
The Expy runs EXACTLY like it did before. No noticeable improvements whatsoever. This is not really a bad thing, though. It seemed to run just fine before I changed the plugs/wires.
I just thought that with 114k miles on the original plugs/wires, I would feel SOME improvement in throttle response, acceleration, etc......NOPE.
FWIW, the specified gap for the plugs is .054". The center electrodes on the plugs I removed were burned down to approx. .075". This is one reason I expected to feel some noticeable improvement in power, etc.
Oh well, nothing ventured, nothing gained. Maybe the gas mileage will improve a little with new plugs/wires.
Last thing....If you have an Expedition 4.6L or 5.4L: Unless you REALLY, REALLY enjoy working on it, pay to have this particular job done for you. For me, it was a MAJOR PITB. If I'd had an extra $200 laying around, I definitely wouldn't have done this job myself.
Wayne,
PITA...yes
But
You know that all of them has been changed properly.
Because of the location of the back 2 plugs (you know the ones) many shops skip those.
When I changed my plugs, the back 2 were different brands.
Also, when you do it, you KNOW that they aren't cross threaded.
Torque to 15lbs without antiseize, any tighter and they could pop out of the head, I kid you not.
Now here is the unbelievable part... there are guys (who drag race) who can change the plugs in 40 minutes!!
Try resetting the ECU (computer).
Take the negative lead off of the battery for 10 minutes. This will reset your ECU and the computer wil relearn its fuel trims and spark advance with the new parts.
I believe (and I could be very wrong) that it take 6 to 10 full run cycles (cold start, up to operating temp with mixed driving, cool down to ambient temp is one run cycle) for the computer to re learn the adjustments with the new gear.
PITA...yes
But
You know that all of them has been changed properly.
Because of the location of the back 2 plugs (you know the ones) many shops skip those.
When I changed my plugs, the back 2 were different brands.
Also, when you do it, you KNOW that they aren't cross threaded.
Torque to 15lbs without antiseize, any tighter and they could pop out of the head, I kid you not.
Now here is the unbelievable part... there are guys (who drag race) who can change the plugs in 40 minutes!!
Try resetting the ECU (computer).
Take the negative lead off of the battery for 10 minutes. This will reset your ECU and the computer wil relearn its fuel trims and spark advance with the new parts.
I believe (and I could be very wrong) that it take 6 to 10 full run cycles (cold start, up to operating temp with mixed driving, cool down to ambient temp is one run cycle) for the computer to re learn the adjustments with the new gear.
Thanks, 'tard.
You are correct. I do know that everything was done to my specifications. Even an experienced, honest mechanic would not have taken the time to double & triple-check everything the way I did. Praying a lot during the job didn't hurt, either.
I disconnected the negative lead before I started the work, so the ECU is currently in the re-learning process.
You're right about the back 2 plugs. Major trouble getting to them. Thank God I have small hands. Getting to the back plugs on the passenger side was much more difficult than the drivers side, because of all the heater hoses & electrical wires.
As far as the racers' 40-minute plug change is concerned, that is truly incredible. If I could do that, I would jump back & kiss myself.
You are correct. I do know that everything was done to my specifications. Even an experienced, honest mechanic would not have taken the time to double & triple-check everything the way I did. Praying a lot during the job didn't hurt, either.
I disconnected the negative lead before I started the work, so the ECU is currently in the re-learning process.
You're right about the back 2 plugs. Major trouble getting to them. Thank God I have small hands. Getting to the back plugs on the passenger side was much more difficult than the drivers side, because of all the heater hoses & electrical wires.
As far as the racers' 40-minute plug change is concerned, that is truly incredible. If I could do that, I would jump back & kiss myself.
UPDATE
When I replaced the Expedition's plugs & wires last weekend, I filled up the tank (at the station a mile from home) prior to doing the job. Since I started with a full tank of gas, I was able to accurately calculate the mpg improvement.
I just re-filled the tank today. I got 295 miles on 17 gallons of gas, or 17.35 mpg.
YIPPEEEEEE!!!!! That's quite an improvement over the 14-15 mpg that the Expy was getting.
[ September 11, 2005, 09:28 PM: Message edited by: wavinwayne ]
When I replaced the Expedition's plugs & wires last weekend, I filled up the tank (at the station a mile from home) prior to doing the job. Since I started with a full tank of gas, I was able to accurately calculate the mpg improvement.
I just re-filled the tank today. I got 295 miles on 17 gallons of gas, or 17.35 mpg.
[ September 11, 2005, 09:28 PM: Message edited by: wavinwayne ]
Yay! It was worth it!
Good job. The next time will take half as long, honest.
I've changed mine 3 times, the last set are copper core plugs that I side gapped.
Actually I found the back 2 plugs on the drivers side were the worse ones because of how the fuel rail and regulator are positioned.
Good job. The next time will take half as long, honest.
I've changed mine 3 times, the last set are copper core plugs that I side gapped.
Actually I found the back 2 plugs on the drivers side were the worse ones because of how the fuel rail and regulator are positioned.
- Status
