'04 5.4L Oil consumption observation
#1
'04 5.4L Oil consumption observation
I have a 2004 with 5.4. I have had it since around 30,000 miles, and currently have 326,000 miles on it. I have used motorcraft 5-20 and motorcraft filter since day 1. Timing chain tensioners and guides were replaced at 178,000 miles (I even posted a write up about it here with photos). Replaced a leaking oil filter mount gasket around 200,000 miles. Other than plugs, COPs, and throttle body cleaning, I haven't really had to do anything to the engine. I change the oil every 5000 miles, and for the first 270,000 miles or so, I never even had to add oil between changes. It is now starting to burn oil between changes, and I usually have to add 3 quarts between oil changes. I know with 326,000 miles, I should expect some oil consumption, but here is the observation that kinda has me baffled: During the first 2500 miles after an oil change, it uses very little oil, around 1/2 of a quart. the remaining 2 1/2 quarts of consumption comes in the next 2500 miles before the oil change. Anyone know why that might be? No CEL lights, no noticeable loss of power, no noticeable leaks under the truck.
#2
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#5
326,000 successful miles is not what I'd call a problem, lol. As reliable as that engine has been, I'd be A-OK with that oil consumption. But yea, the manner in which it uses it seems odd, but as good as that motor has been to you, you almost just wanna say "oh well". If I were adding that much oil, I might even consider stretching out the change interval a little bit.
#6
at about 1700+ miles, additives in the oil begins to break down......by 2500 miles, much of the additives are at their minimums.......we use to add zinc to our oils back in the 70's to reduce friction with the racing side of the house.....we did some testing in our street cars to try to establish a reference point of longetivity...and that's what we came up with
#7
With 326k, you are going to have some blowby. The blowby depletes the additive package and lowers the viscosity faster than in a tight engine, so it starts burning it. This is why I suggested 3k change intervals, or a heavier oil. If you go heavier, do not get anything that's more than 5W on the lower end, your VCT will hate you.
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#8
An observation of mine that relates, and confirms @glc and @beachkid's opinion, is a distinct decline in oil pressure relative to miles on the oil change. I have a very nice fancy electronic analogue / digital aftermarket oil pressure gauge on my 2004 5.4L with 221k miles. Hot idle (verified by OBDII reading of EOT) oil pressure with A/C on, in gear, will be 27.5 lbs right after a fresh oil change with 5w30 Full Syn Moblie 1. At 2500 miles, the oil is still pretty and clean - and no more than one quart consumption, but Oil pressure under will be around 25 lbs. By 4000 to 5000 miles, color begins to darken progressively and by 5000 the oil pressure will hover around 23 lbs.
I think the oil becomes diluted with some hydrocarbons and combustion products from blow-by along with a breaking down effect.
PS. Forgot to mention that at 212K, did a complete chain/phaser job and installed a Melling 10340 Oil Pump (definitely boosting oil pressure).
I think the oil becomes diluted with some hydrocarbons and combustion products from blow-by along with a breaking down effect.
PS. Forgot to mention that at 212K, did a complete chain/phaser job and installed a Melling 10340 Oil Pump (definitely boosting oil pressure).
Last edited by F150Torqued; 01-06-2017 at 07:04 PM. Reason: Afterthought
#9
Thanks for the info. I was sure that I was getting blowby at 326K miles, but I wasn't quite sure why the curve in oil consumption. I've used the 5-20 exclusively because of the vct system. If I do switch to 5-30 will that not mess up the VCT? Will it really help reduce blow by that much? Originally, I had just planned to keep going every 5000 miles with 5-20. I mean, it's worked pretty good so far.
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#11
Yes, I've been ridiculously happy with the reliability of this engine. What's even more impressive is that all the parts that you would expect to have needed replacement have not needed it. Starter, water pump, alternator, A/C compressor, Power steering pump...all original. I might try adding the thicker oil between changes. What about an oil additive like STP or Restore to help slow the breakdown of the oil? I've never used additives before with this truck. I had come to the conclusion that they were not worth the money, but then again, I've never had an engine with this many miles before either.
#13
Anyone know why that might be?
#14
at about 1700+ miles, additives in the oil begins to break down......by 2500 miles, much of the additives are at their minimums.......we use to add zinc to our oils back in the 70's to reduce friction with the racing side of the house.....we did some testing in our street cars to try to establish a reference point of longetivity...and that's what we came up with
You have no idea what you are talking about. 2500 miles the additives are at their minimums???????? In case you haven't noticed this isn't the 50's, 60's, or 1970s.
Last edited by Paul888; 01-10-2017 at 09:28 PM.