Looking for a good 5.4liter mechanic
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Category: Other Topics
Forum Name: Shops, Barns, Varmints, and Trucks
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URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=207107
Printed Date: 18 Jun 2025 at 2:29am
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Topic: Looking for a good 5.4liter mechanic
Posted By: bobkyllo
Subject: Looking for a good 5.4liter mechanic
Date Posted: 15 Jun 2025 at 10:49pm
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My 2008 f150 5.4 has been giving me the raspberries lately. Normal driving regardless how much driving everything is fine. But lately I've noticed with a trailer following me and I go about 14 miles or more when I come to a stop my motor will miss pretty bad and you will here a knocking sound. Get it just above idle and things smooth out very nicely. At first I thought it needs timing chains but that wouldn't come and go depending on the style and amount of driving. Is it possible to have some bad vvt oil selenoids? Once things cool down even with the trailer it is fine until you put some more miles on. I'm hoping you don't tell me to put new phasers in I'm not looking forward to that. |
Replies:
Posted By: Dave H
Date Posted: 16 Jun 2025 at 9:04am
Freind and a mostly succesful mechanic is being plagued with similar problems with his 5.4. I will keep you in mind if he ever solves his problem and I ask you do the same. 
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Posted By: steve(ill)
Date Posted: 16 Jun 2025 at 9:21am
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the variable cam timing is operated by OIL... Your OIL is getting hot / thin out / and not doing its job with the VCT, loosing pressure.... when it cools off, things work better.... when the engine speed picks up 200 RPM from idle, the pump pressure goes up and you dont have a problem. I would change oil.... You might even want to go a grade higher.... Are you running 5w30 ? Might try a 10w30 or even a 10w40 for the SUMMER and see if that helps. ----------- high milage, some pump wear, some loss of pressure at low RPM....
------------- Like them all, but love the "B"s. |
Posted By: Dave H
Date Posted: 16 Jun 2025 at 10:24am
| good thoughts Steve, I will check to see what kind of slickum my friend is using. |
Posted By: bobkyllo
Date Posted: 16 Jun 2025 at 2:43pm
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Steve you make very good sense. I wouldn't consider 165000 miles high miles but perhaps it is high enough in this case. I'm sure i put 5w20 in it the last time I changed oil. What are your thoughts on Lucas? I've had great success in regular motors with no vvt but I'm not sure how this style motor would feel about having Lucas in it. |
Posted By: bobkyllo
Date Posted: 16 Jun 2025 at 2:44pm
| What are your feelings in a 5w40 oil? Thin when cold thicker when warm |
Posted By: Dirt Farmer
Date Posted: 16 Jun 2025 at 3:24pm
| Are there any codes coming up or is the check engine light on, if in doubt you can use a scanner in auto parts lot to see codes. If that's not an option literally Google your truck model engine etc and issue you're having as a sentence in the Google search and a whole list of advice will come up, none of which I saw mentioned using thicker oil, you have to watch going thicker as other tolerances in bearings are very close and could cause other issues. Let us know what you find out. I'm more of a GM person but curiosity got the best of me so I googled like I mentioned above. Good luck. While you're at it see if you can get a solid answer for where the blue fluid in the oval goes for ol Freegas. Just had to throw that in but he's probably waiting on a train in search of a fish samwich. |
Posted By: steve(ill)
Date Posted: 16 Jun 2025 at 3:46pm
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FORD lists the 5W20 to get VERY THIN OIL for less friction / drag and gains .0001 % better fuel economy... It is little if anything as a BENIFIT for the motor... Switching to 5W30 might be all you need to fix the PSI at IDLE... 5W40 would surely get you more pressure, but thats a big jump right off the bat... I would try the 5W30 for a test and see how it does... That would be fine for the winter also... Nothing wrong with 10W30 either.. ------------- Like them all, but love the "B"s. |
Posted By: Lars(wi)
Date Posted: 16 Jun 2025 at 5:45pm
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If low oil pressure at idle is indeed discovered to the issue, a couple routes can taken; Make an adjustment to the engine ECM, to have the ‘low idle rpm’s’ bumped up to hopefully enhance oil psi at idle. Change the oil and filter to a higher weight of oil, pay attention to the the lowest number of the grade of oil, the higher number is irrelevant at this time. A 10w30 is thicker oil that 0w40, it is simple physics, oil gets thinner as it gets warmer, no ‘higher 2nd number’ is gonna change that. I don’t care how many additives/emulsifying ingredients are added, the motor oil will get thinner as it gets hotter. There very well could be a mechanical issue with the engine, oil pump itself may be getting tired, and less able to produce pressure as the pump gets hotter. ------------- I tried to follow the science, but it was not there. I then followed the money, and that’s where I found the science. |
Posted By: steve(ill)
Date Posted: 16 Jun 2025 at 5:54pm
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Lars is correct to an extent on the viscosity... Many would look at this and say 5w vs 30w vs 40 w...... the TRUTH is that 5 wt oil at 32 degrees is THICKER than 40 wt oil at 212 degrees.... YES , 5w20 is thinner than 5W30 at 212 degrees... but going to 10w30 makes a BUNCH of difference ! ............... i dont see any advantage to 5W40 and think that is too much "SPREAD" in the numbers.. lots of addatives... 10w30 is a GOOD CHOICE. ------------- Like them all, but love the "B"s. |
Posted By: jaybmiller
Date Posted: 16 Jun 2025 at 6:17pm
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hmm.. anyone add an oil 'cooler' somewhere ? ------------- 3 D-14s,A-C forklift, B-112 Kubota BX23S lil' TOOT( The Other Orange Tractor) Never burn your bridges, unless you can walk on water |
Posted By: TedN
Date Posted: 17 Jun 2025 at 12:44am
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Not a recommendation but an observation - where I work we run several V10s, not the same engine but similar. When I started in 2006 the Ford recommendation was 5w-20. Our supervisor at the time insisted we run 15w-40 diesel oil, so we would occasionally have a lash adjuster stop working and prop a valve open. The more recently purchased V10s call for 5w-30. This may be because they only put the V10 in the E450 and weren't worried about fuel mileage, I don't know. Our newest E450s use the V8, I haven't worked on one yet so I haven't looked up the oil requirement. And yes, that supervisor is gone and we use recommended oils now. Ted ------------- 190XTD seriesIII, 190XTD seriesI, maroon belly 7000, 190XTD series??? project(or maybe parts) |
Posted By: steve(ill)
Date Posted: 17 Jun 2025 at 9:14am
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More on what LARS was saying.. Here is a graph that shows the oil viscosity vs TEMP... to the left is COLD ENGINE... to the right is HOT ENGINE... Note that the 10w oil when COLD is thicker than the 20 or 30 wt oil when HOT.... Switching from 5w20 to 5W30 will gain you a little bit of viscosity when HOT and may be enough to fix the low psi problem.. Switching to 10w30 will gain you viscosity at IDLE and all the way up the RPM range until you get to operating temp.. The 5W30 would be an EASY test as you just get a little more PSI at HOT ENGINE... but not much difference from COLD as the engine warms up thru the range.. If you want a LITTLE MORE EVERYWHERE... then the 10w30 would be a good bet. Going to 15w40 or 20w50 is NOT a good idea... too much change at the COLD END.(for a NEWER VCT engine).. and some advantage at the HOT end. ( unless you are in south Texas and the "COLD" is 70 degrees F ) .... note the curve is in CELCIUS not Farenheit..  ------------- Like them all, but love the "B"s. |