what are the dangers of using the wrong oil in a 5.4 like one that requires 5w20 but you find out it has been running shell rotella 15w40 for since almost new with 3,00 mile draqin intervals and is there any harm to go back to 5w20 or 5w30

 

I read somewhere (on here I think in the 04 F150 forum or the modular motor forum)that someone found out the largest failure of the new 5.4 motor is the use of too thick oil cloging gallies or not being able to get through gallies in the motor. From what I read the lower end gets oil starvation.

I would get it changed back to 5W30 or 5W20 right away. changing back should not be a problem. The problem comes in when you mix weights. Yes there will still be some of the 15W40 but after about 6K (2 oil changes) everything should be fine and back to normal as long as you use the same oil (the 5w20 or 5w30).

 

which would you reccomend i use

 

15W-40 is WAY too thick/heavy for these engines. You are only hurting it by going with that heavy of a viscosity. These are modern OHC engines built with much tighter clearances versus the old style pushrod OHV engines that could use "thicker" oils. These Modular engines were built to best run on today's 5W-20 and 5W-30 oils. And in all reality if you are going to use a "dino" 5W-30 oil you might as well use Motorcraft 5W-20. It's a high quality semi-synthetic oil that doesn't shear like a regular dino 5W-30. A regular "dino" 5W-30 usually shears to a 20 weight oil in a short time period leaving deposits. If you are going to use a "real" synthetic oil, such as Mobil 1, then the 5W-30 weight oil is fine. It's shear stable. If you want to see Used Oil Analysis' of Motorcraft 5W-20 oils in the Ford Modular engines check out www.bobistheoilguy.com and use the search function in the used oil analysis section. It's a wealth of information.

Whimsey

 

what about running 10w30 or 10w40 in a 98 4.6 that calls for 5w30?? (sorry to hijack)

 

No offense to anyone but I would just use the oil that is recomended by the manufacturer. They build the motors and put in a certian oil for a reason. If somthing should happen to your motor and they find out you wern't using the correct type(weight) you could have a good battle on your hands to get it replaced under warranty. I am not saying they will not replace it just that with some service departments it could be more difficult.

As for me I have been running Amsoil 0W30 in my Focus that calls for 5W20 and have had no problems, in fact my MPG went up a but. I plan on using the same 0W30 in the F150 as soon as funds come avaible to purchase an 04 or 05. I only decided to use the 0W30 after I found out what the recomended weight oil is and the reason for using it.
One last thing. I may be wrong but I heard, by owning a focus, that ford started putting 5W20 in it starting on 01(2000 focus came with 5W30) to get a better fleet PMG rating. A single car will not see the MPG rise but in a fleet it will bump up the average a gallon or so. Again I just heard this and have no proof but it seems to make some sence.

 

This is serious stuff we are talking about here. We are in the automotive engine rebuilding business. We began seeing engine failures prettty early in the history of the 4.6/5.4 engines, after warranty expired. I can't talk to the issue of how Ford was handling these under warranty.

Folks were taking their cars and trucks to quick change shops or changing the oil themselves and just using what they had been using in the past, typically a 10w-30 or 10w-40 oil.

Our trade technical association - Automotive Engine Rebuilders Association (AERA) issued a technical bulletin on this a number of years ago. The finding:

It is absolutely critical for long engine life that the engine oil be strictly according to Ford's specs and that the lower viscosity number must be 5. I repeat 5. That means 5w30 or 5w-40 is you can find it for summer time use. Don't use 10w-whatever oils, or 20w-something oils. Period.

What happens is that there are very small drain holes in the cylinder heads (I'll avoid the technical stuff) and the oil pools up there and does not drain fast enough back into the block if it is too thick. This starves the bottom end of the engine and leads to premature wear and bearing failure.

We have not found that in this application that synthetic oil is any improvement for this issue. It is viscosity which is critical. By the way, we are not in the oil change business, but you should know that additives in the oil, including some of the viscosity fixers begin to wear out much earlier than most people think. By 3,000 miles most of those additives have broken down, even if the oil "looks" good.

Happy motoring - use the right viscosity oil or you'll be seeing us or someone like us sooner than you think!

 

My thoughts exactly. Ford recommeds 5W20 for a specific reason. That's why I use Motorcraft 5W20 no matter what the temp is. I have towed 7000lbs in 98 degree heat with the a/c on and never had any issues with my 2001 5.4L.

 

well my 97 4.6 has had 10w-30 Castrol GTX w/ Fram filter since it was new. when i got it recently with 112,000 miles from my grandfather, I went to 5w-30 Valvoline w/ a Motorcraft filter now it has 116,900 miles and counting. no problems so far. (knock on wood)

 

I use the Motorcraft 5W20 in my 2002 F-250 and my new 2004 E-450 6.8 motorhome chassis. In fact, here in Phoenix if you go to a Ford or Lincoln/Mercury Dealer Fast Lube that is the recommended oil. That oil is a very fine product and these new engines need thin oil due to tighter manufacturing processes.

 

Exactly! Ford would have suffered penalties if they didn't meet CAFE standards. The 5-20 oil, being thinner, pumps easier, and gives a very small amount of increase in MPG. There have been NO changes to any of the motors Ford has built for years. The 2000 and on Focus motors are IDENTICAL, but Ford switched recommendations to the thinner oils for the later models. Take a visit to Ford Europe, and you will notice no reference to 5-20 anywhere. That being said, if you choose to run 5-20, bully for you. If you choose to run 5-30, you will not do any harm, and will most likely extend the life of the engine by a measurable amount. I agree that the low number should be 5. But everyone is personalizing this subject way too far, instead of scientifically observing data. A 5-20 will be fine, and MC's offering is VERY good. 5-30 will also be fine, and will protect better in heat. M1 comes to mind here. 5-40 will also be fine, and the Shell Rotella synthetic is a very good offering. If you can find it, German Castrol 0-30 is superior in every respect, and will serve you well in any temp you are likely to encounter, and still be alive in. Look at AutoZone, and read the back of the bottle. If it says "Imported from Germany" you have found repackaged Castrol SLX. It is green colored, and has a smell kind of like gummy bears.
If you keep your low number at 5, you can make a choice as to the high number based on temps and driving conditions, as well as how long you want the engine to last. For the majority of folks, MC 5-20 and a Motorcraft filter will serve you well for over 100,000 miles.

 

NNOOOO!!!

Don't tell everyone about the German Castrol, now there won't be any left at the store when I get there!

 

The 15w-40 the engine has been getting is on the border line of causing damage. Any oil with a viscosity rating over 40 will cause hot spots in your engine as the oil doesn't flow as fast and the cooling from the oil is diminished. I assume we are talking about your 2003 Expo. Depending on the miles this engine has with the 15w-40 would determine the viscosity I would recommend. If you are over 50,000 miles, I would stay with a 5w-30. The engine has been broken in with a strong wedge front of oil in front of the main bearings which will now be slightly "loose" because of it. You may end up with low oil pressure at temp which will accelerate wear. If you are less than 50,000 miles, switch to the 5w-20 in any of the brands and it should run significantly better and fuel mileage will surely go up.

 

My dad just bought a used 03 f150 4x4 5.4 it has 15,000 miles on it PO used 10w-30 should there be much damage to the engine

 

Hard to tell from your post whether you have a problem. Where was this truck located for its first 15,000 miles? If it was in the South and most of the mileage is in the summer months, things are probably O.K. If it was in a cold climate and driven a lot in the winter, there could be trouble.

But, if the engine runs quietly, smoothly, has no evidence of internal wear (next oil change, cut open the oil filter and look for any particulate matter), if it does not use any oil, if compression is good, then you may have caught things in time.

In any event, switch to a good 5w-20 or 5w-30 dino oil or one of the 0w-20 or 0w-30 synthetics. Change oil every 3,000 miles and always replace filter with a good one, no off brand stuff.