How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Chris (aka- Moose) Your Own Question
Chris (aka- Moose)
Chris (aka- Moose), Technician
Category: Ford
Satisfied Customers: 43860
Experience:  16 years experience
Type Your Ford Question Here...
Chris (aka- Moose) is online now
A new question is answered every 9 seconds

quarts..changes in my 2002 f15 supercrew with the 5.4L...synthetic oil

Customer Question

I use about 2 quarts of oil between changes in my 2002 F15 Supercrew with the 5.4L. The truck has 62k on it and I have used fully synthetic oil since around 25k. Any idea what is causing this? Also, can I go back to the semi synth 5w-20 after using full synthetic for so long?
Submitted: 7 years ago.
Category: Ford
Expert:  Chris (aka- Moose) replied 7 years ago.

Hello XXXXX'm Chris, a current Ford Lincoln Mercury employee.


Thanks for visiting Just Answer. I will do my very best to help you resolve your concerns.


What brand and grade oil have you been using?

At what interval are you changing your oil?

How much oil do you put it when serviced?

How long do you let it sit before checking the level?

Customer: replied 7 years ago.

What brand and grade oil have you been using? Normally Pennzoil or CastrolFull Synthetic 5w-20.


At what interval are you changing your oil? Every 5k.


How much oil do you put it when serviced? 6qts per the service manual.


How long do you let it sit before checking the level? Usually right after the oil change then again a few hours later.



Expert:  Chris (aka- Moose) replied 7 years ago.

If its burning oil then there is not much you can do accept replace the engine. If you notice a puff of smoke on startup then most likely it is valve stem seals. I personally only run the oil which the people whom built the engine specify, I do not believe the full synthetic has caused this but it is not recommended and motrcraft oil may have different polymers and additives needed which other brands do not have. According to ford the oil loss over 5k is within specs. I personally think no oil should be lost but we cant even warrnty claims like this since it falls within specs. I do suggest you replace the PCV as it may be a fault and allowing oil deposits to get into the intake. Another suggestion is to swap back to motorcraft 5w20 and change the oil at 3 or 4k intervals. I know this may be a hassle but the other options are to run it low on oil or do engine work. Neither you nor I would choose that do to expense.

If you would like fords oil consumptiontest and specs reply and I will gladly post them for you

Chris (aka- Moose) and 4 other Ford Specialists are ready to help you
Customer: replied 7 years ago.

So if Ford claims this amount of oil loss to be normal then there really isnt an issue with the engine is there? Is there nay issue with sticking with the full synthetic and just making sure it is topped off?


I'd like the oil consumption test and specs please.

Expert:  Chris (aka- Moose) replied 7 years ago.

Personally I think the full synthetic will be fine to continue to run and just keep it full. Like I said earlier I do however prefer motorcraft brand since its a ford product. Do check that PCV valve though. According to ford there is not an issue but as a tech or customer like yourself it would not set well with me knowing my vehicle was using oil.

I have owned about 9 ford trucks and have only used ford products to service them and so far I have not had a oil consumption concern. We get this concern at my dealer about 1 every 3-4 months. Many of them turn out to be used vehicles which were previously mistreated and not the current owners fault.

CLICK HERE for the test