4.6 DOHC Oil Change Interval

[c3po]

I have a 2004 Mercury Marauder that has the 4.6 DOHC Engine, I am coming up on 30,000 miles. The owner's manual says to change the oil every 5000 miles.

I will probably be putting on 15,000 to 20,000 miles a year on the car, I plan on keeping an Amsoil EaO Oil Filter on for a year.

I have an AFE Pro Dry Air Filter, and I plan on changing the PCV every 30,000 miles. I will also be putting on a Catch Can.

The car does not see short trip driving.

I can maybe do 2 oil changes with the Pennzoil Platinum, running it out to 8000 miles, or I can do a yearly oil change with the Amsoil OW-20. Obviously the Platinum would be the 5W-20.

I went through the used oil analysis section and I only saw 1 UAO for a Marauder. I will probably have to get a UOA done to see how long I can take the Amsoil OW-20 or Pennzoil Platinum out.

I also plan on running a Maintenance Dose of auto-rx after I finish this Clean and Rinse. I have heard these 4.6 Engines are good, but is there anything I need to watch out for.

If I did a yearly oil change with the Amsoil OW-20 would it be wise to change the PCV Valve out once a year.

I drive the car like a normal person, and I am averaging 23 m.p.g. I also use Amsoil PI once a year.

I know this is overkill, but I have a Filtermag on my Amsoil EaO Oil Filter, some people have said with the Filtermag on there I could probably get away with a Motorcraft Oil Filter.

I am open to suggestions from anyone with experience with these 4.6 DOHC Engines.

 

[addyguy]

If you're comfortable doing once a year 10k + changes, then yeah, ASM once a year would be a great plan. There have been some really, really impressive runs with this oil recently - there was Taurus V-6 that went 28k miles on it, and it looked perfect.

 

[03cvpi]

I've had several 4.6l over the years and there are still 3 in the family. For oil changes, do not exceed the mfgr mileage interval until the car is out of warranty, as doing so could void the warranty. As for the pcv and catch can, unless the car is using oil, don't bother with the catch can and the pcv should easily last 100k. I have used Amsoil 0w20, pennzoil 5w20 and schaeffers 5w20 in my 4.6's, I actually prefer schaeffers 5w20, it just seems to run quieter. And without a UOA I would not run beyond 15k even with Amsoil. Every engine is different, one engine that can keep the oil clean for 20k has a sister engine that will trash the oil in 8k. The motorcraft filter is really good, but I don't think I would run the filter beyond 15k.

 

[c3po]

Originally Posted By: addyguy
If you're comfortable doing once a year 10k + changes, then yeah, ASM once a year would be a great plan. There have been some really, really impressive runs with this oil recently - there was Taurus V-6 that went 28k miles on it, and it looked perfect.


That's why I posted about the Amsoil OW-20, I was seeing people post about going well over 15,000 miles on an oil change.

Did Amsoil address the issue it had a while back with there oil thickening up after 10,000 miles. The reason I ask is there was an old post where they did an oil analysis on Mobil 1 and Amsoil, I think it was The Synthetic Oil Life Study. They were also supposed too test Redline and Royal Purple, but the study just stopped. They were also going to test dino oil, did somebody tell them to stop and if they did not they would get sued.

 

[addyguy]

Yeah, they have. Both ASM 0W-20 and SSO 0W-30 don't thicken up appreciably in service at all.

 

[rg200amp]

The 4.6 is in MANY cars. There are countless 4.6L UOAs. Check crown vics, towncars, f-150, mustang GTs, ect. . .

Since you see no short trips, a once a year oil change can be done useing a quality synthetic like Pennzoil platnium, Amsoil, ect. . .

Your usage looks like a good chance to try Castrol Edge. That would be an intresting UOA to see after a year of use!!!!

 

[tig1]

FYI my 96 Mercury Grand Marquis 4.6 has 206,000 miles and it gets 10,000 OCIs and still runs great. IMO I wouldn't run any oil past 10,000, because by the time you add up your top off oil, filter changes, etc. you have paid for another oil change. Oil is just too cheap to test the limits of lubrication.

 

[c3po]

Originally Posted By: rg200amp
The 4.6 is in MANY cars. There are countless 4.6L UOAs. Check crown vics, towncars, f-150, mustang GTs, ect. . .

Since you see no short trips, a once a year oil change can be done useing a quality synthetic like Pennzoil platnium, Amsoil, ect. . .

Your usage looks like a good chance to try Castrol Edge. That would be an intresting UOA to see after a year of use!!!!


There are many 4.6 UOA's, but many of these are the SOHC Engine or the cast iron 4.6L Engine.

Isn't Castrol Edge something like $34.00 for a 5 quart jug at Wal-Mart. I would go with Pennzoil Platinum for $23.00 a jug at Wal-Mart.

 

[RF Overlord]

c3po, I have been running PP 5W-30 in both of my Marauders since telling ExxonMobil to get bent.

The daily driver has 115,000 and has been run on PP for the last 2 oil changes. I've noticed the motor seems a tad quieter and also that oil usage has dropped from about a quart in 2,500 miles to a quart in over 4,000. (I do 5,000-mile OCIs on both cars)

I don't notice any difference in the blower car, but it has a lot less miles.

As far as your PCV valve, I agree with 03cvpi...there's no need to change it so often.

 

[Art_Vandelay]

Originally Posted By: tig1
FYI my 96 Mercury Grand Marquis 4.6 has 206,000 miles and it gets 10,000 OCIs and still runs great.


What oil and filter combinations have you run for 10,000 OCI's? How much makeup oil does the 4.6 need for that kind of interval?
Any short trip driving?

 

[c3po]

Originally Posted By: Art_Vandelay
Originally Posted By: tig1
FYI my 96 Mercury Grand Marquis 4.6 has 206,000 miles and it gets 10,000 OCIs and still runs great.


What oil and filter combinations have you run for 10,000 OCI's? How much makeup oil does the 4.6 need for that kind of interval?
Any short trip driving?


Good question, I would like to know the same thing.

 

[tig1]

Originally Posted By: c3po
Originally Posted By: Art_Vandelay
Originally Posted By: tig1
FYI my 96 Mercury Grand Marquis 4.6 has 206,000 miles and it gets 10,000 OCIs and still runs great.


What oil and filter combinations have you run for 10,000 OCI's? How much makeup oil does the 4.6 need for that kind of interval?
Any short trip driving?


Good question, I would like to know the same thing.





Just like clockwork I add one qt. at 6000 miles. It's been like that from the beginning. I use M1 10-30 most of the time, but have M1 5-30 now. Pure one filter. Have made a lot of long trips with this car. One trip to Maine, one to Colorado, and 16 trips to Florida all from Illinois. At the end of this week, going back to Fl. have family there. M1 has kept this engine very clean and quite. Also a lot of town driving.

 

[c3po]

Originally Posted By: tig1
Originally Posted By: c3po
Originally Posted By: Art_Vandelay
Originally Posted By: tig1
FYI my 96 Mercury Grand Marquis 4.6 has 206,000 miles and it gets 10,000 OCIs and still runs great.


What oil and filter combinations have you run for 10,000 OCI's? How much makeup oil does the 4.6 need for that kind of interval?
Any short trip driving?


Good question, I would like to know the same thing.





Just like clockwork I add one qt. at 6000 miles. It's been like that from the beginning. I use M1 10-30 most of the time, but have M1 5-30 now. Pure one filter. Have made a lot of long trips with this car. One trip to Maine, one to Colorado, and 16 trips to Florida all from Illinois. At the end of this week, going back to Fl. have family there. M1 has kept this engine very clean and quite. Also a lot of town driving.


Do you think that you had to add a quart of oil because you were using 10W-30, I think they back speced 5W-20 to 1994 or around that time.

Was your consumption oil leaks, or was it burning oil.

 

[tig1]

No leaks at all. It uses a qt. at 6000 miles whether I use 10-30 or 5-30. Doesn't seem to matter. I've never used 5-20. Just can't bring myself to use that weight. Old school I guess. I changed oil 1200 miles ago and oil is still remarkably clean.

 

[c3po]

Originally Posted By: tig1
No leaks at all. It uses a qt. at 6000 miles whether I use 10-30 or 5-30. Doesn't seem to matter. I've never used 5-20. Just can't bring myself to use that weight. Old school I guess. I changed oil 1200 miles ago and oil is still remarkably clean.


I am stumped, have you changed or checked your PCV Valve lately.

 

[tig1]

Yes. I changed it even though it has always remained very clean.
I think 6000 miles on a qt. is very good oil consumption. I owned a 91 Ranger and it took a qt. every 3500 miles. My son now owns the truck and it has 327,000 miles on it, all with 10,000 OCIs. M1 10-30.

 

[Ben99GT]

Originally Posted By: 03cvpi
As for the pcv and catch can, unless the car is using oil, don't bother with the catch can and the pcv should easily last 100k.


The PCV should be replaced every 30-50,000 miles on the 4.6Ls.

The catch can is a not a bad idea on high-revving 4V Modulars.

 

[c3po]

Originally Posted By: Ben99GT
Originally Posted By: 03cvpi
As for the pcv and catch can, unless the car is using oil, don't bother with the catch can and the pcv should easily last 100k.


The PCV should be replaced every 30-50,000 miles on the 4.6Ls.

The catch can is a not a bad idea on high-revving 4V Modulars.


I can see what Ben99GT is saying, how can a PCV Valve go 100,000 miles, what if someone only drives there car 5000 miles a year, do they keep the PCV Valve on for 20 years.

I say this becuase my Dad is lucky if he puts 5000 miles a year on his Marauder, he probably averages 2000 to 3000 miles a year.

 

[Art_Vandelay]

Originally Posted By: tig1


Just like clockwork I add one qt. at 6000 miles. It's been like that from the beginning. I use M1 10-30 most of the time, but have M1 5-30 now. Pure one filter.


Mobil 1's worth the money if it takes you to 10K. Your real world experience with two 4.6's are pretty solid evidence to consider.

Do you think a Motorcraft filter can go the whole 10K interval?

 

[tig1]

Yes, as long as you start off with a clean engine and using Synt. oil.