KCAP

Not sure where to go with this problem, thought the experts might have some thoughts that I have not.

I have a 2005 Lairat, 2WD, 5.4 with 99,000 miles. Love the truck it is my second of the new body style. Normally, I trade off every 2-3 years, with the economy and job security the way it is this last year, I am not sure Obama is going to wave his majic wand over me or my family, so I think I better hold on to this one for another year or so.

With that in mind, last week I was due for an oil change which is normally done at Jiffy Lube but one of my maintenance techs that work for me offered to change out most of my other fluids as well once he heard me say my truck was reaching the 6 digit mark. So cool, that should save me some serious jack and took him up on it.

We changed the tranmission fluid and filter and added some Lucus, changed the rear end fluid, air filter, power steering fluid changed the wiper blades, cleaned the injectors with some sea foam and yes of course changed the oil and filter only this time adding some Lucus there also.
(Thought the Lucus might quite it down a bit, which it did).

All is well, until the 45 mile drive home from work. About 20 miles into the drive running about 60-65 mph and the truck shuts down, information center is reading "Engine Fail Safe" and flashes over to read "Low Oil Preasure". I worked (coasted) my way to the side of the highway, got it stopped, put it in park, shut the key off and restarted it. Preasure is reading fine on the guage, engine light is on. Shut it back off, checked the oil level, all is good. Inspected the under truck for fluids with nothing found. Started it back up and took off. Hmm?

About 10 miles down the road, it does the same thing, only this time, not in a good spot. I repeated the same steps as the previous and ended up getting it home. Pissed off at my truck, I called they guy that helped me do the fluid changes. He was in disbelief, never heard of such a thing for what we did and the levels still at full. Had just done the same thing to his dads 2005 F150 and no problems.

He suggested checking the oil sending unit connection next the the oil filter, possibly got some power steering fluid on it from changing it out. If not, try flashing the computer. Which I did, of course there goes any codes but it seemed to do the job for about a week staright, then yesterday it happened agian, WTF?

It seems to me that oil preasure is either there or it is not, it is not a intermitent problem. If that is ture then I guess electrical my have some play here. It could be the lead to the sending unit maybe it has a short or a wire may be loose from being in such a close location to the filter. I could see that being in the way of hands while putting the oil filter back on. Or it could possibly be the sending unit it self.

I think I will take all the equations out of it and have the oil and filter changed again (just in case it has something to do with the Lucus) and replace the sending unit, it's only $8.00 at Auto Zone.

Anybody have any ideas, I appreciate your help.
Thanks,

Mod (Ret.)

I would not bother changing the oil and filter just yet, as I don't see this as the problem. Lucus oil treatment provides additives such as ZDDP and other wear agents, which will not cause low oil pressure, or any other oil problems; it's good stuff.

In reading your post, you did not indicate any oil leaks, so I'll assume you are not loosing oil. Did you check the dip stick to see if it's at the full mark? Our engines take 6 QUARTS of oil to register full. Most oil changing shops advertise an oil change to be an oil filter and up to 5 quarts of oil. Perhaps the oil change tech did not reconize this. Check the dipstick.

If you are mechanically inclined, crawl under the truck and look around the oil filter, power steering pump, and any other area the technition may have been around to see if any wiring got removed, pinched, or broke.

Without being there to look at the truck, I'd say an oil sensor is providing a false reading, but without being able to see if this is the case, I could not give you any positive opinion about driving the truck safely. You said the oil pressure gauge on the dash is providing a "safe" operating range. This is good. You also did not report any noises coming from the engine area, this is also good. When an engine is starved of oil pressure, the first engine part to pitch a fit is usually the rod or crank bearings. You'll know this as they make a horrible "knock knock" noise. Big trouble. The valve train lifters will also make the "click click" noise, but the rod and crank bearings are usually the first to let go with low oil pressure while running at the speeds you indicated.

Call the shop that did the work and ask them if they will cover the towing charges to their shop, as this seemed to happen after they did the work. If they refuse to pay, then have it towed to the closest shop and have it checked out. Let the first shop know this; if the second shop finds the fault and can confirm it happened due to neglegence by the first shop, then you have a case against the first shop to have them pay for the repairs (and towing).

Be polite, but firm. It is possible that this problem happened and has nothing to do with the fluid changes you had done; but unlikely.

99,000 miles is not that big of a deal, and unless you have knoking noises or other engine sounds, I would run that engine for another 100K without worry.

KCAP

Thanks for the information. Glad to hear that the Lucus is in the clear.

Yes the fluids were all up, I have checked everytime this has happened (3 times now) and no leaks, not even a little. I keep everything very clean and any leaks would be hopefully noticed.

The maintenance tech that did the work for me is Kevin, a guy that works for me, so we did it after work in my building. We decided to take your advice and change out the oil sensor tommrow also double check the plug connections to see if there is any loose connections within the plug itself.

I will let you know how it comes out, only tiime will tell.

Thanks for your input.

JCT191

Interestingly enough, my 2005 F150 did the exact same thing this morning on my way to work. Cruising along at 50MPH going downhill, the truck just shuts off. Low Oil Pressure and Engine Fail Safe Mode flashing away.

The difference is, I haven't done any work on it since my last oil change about 4 months ago. The thing that really gets me is the fact that the EXACT same thing happened to me last year at about the same time(mid Jan.)

To fix it last year, I cleared the codes and gave her a little shot of STP gas treatment. BOOM problem gone until this morning.

I will attempt the same remedy again this evening and will let you know how it works out.


Just out of curiosity, is the temp in you area below 10 degrees?? Might be related somehow if it is.

KCAP

Welcome to my world, glad to hear I am not alone.
I am in St. Louis and the temps have been very mild over the last month.

I would say that each time this has happened it was well above 10 degrees. I have not had the chance to change out the sensor as of today, hope to get to it tommorow.

What do you think STP gas treatment does for this situation? I find that kind of interesting as we did do some Sea Foam thru the injectors when we were changing all the fluids.

JCT191

Well after work I threw on the old code reader and got the verdict.

Code were P2111 - Throttle Actuator Control System - Stuck Open.
and
P2104 - Throttle Actuator Control System - Forced Idle.


Not really sure what steps I should take from here any help from anyone would be appreciated.

WHTF150

these modular motors are built with very tight clearences n have a front mounted oil pump wich require thin motor oil,.. so any additives or sludge in the oil might actually cause oil starvation triggering a warning from ecu specially on cold climate. if this was me the first thing i'll do is to flush the motor with mistery marvell oil run a gallon with 2 qrts of regular oil for 30/40 min if using any other cleaning additive follow manufacture recos ( make sure to let the motor idle only, not race it and make sure to not drive it ) then drain n fill up with good engine oil and make sure to use a motorcraft oil filter wich is important.

juallhuce

You have two options. One of them will without doubt 100% fix your truck. One of them may or may not.

1. Replace the throttle body. This is a guaranteed fix. It's not abnormal for me to replace 1 or 2 of these a week for this same problem. Same exact complaints, same exact codes. This WILL fix the problem.

2. Remove the upper plenum(the big plastic box that rides on top of the throttle body) and clean the butterfly with some carb cleaner and a toothbrush.(preferably one you'll never brush your teeth with again) Don't spray too much carb cleaner directly into the intake. Spray most of it on the toothbrush and clean any carbon buildup/gunk you can see. Hit it with one or two shots just to clean any excess off and go drive it. Also, you can pray while you're on your drive. Throttle body's are expensive.

It's just carbon build up that causes the problem. There's no permanent fix other than Ford redesigning the throttle body to better cope with the buildup.

Hope this helps...

Jamie

Mod (Ret.)

If these codes were stored from your last email, I wish you would have posted them. They add an entirely new meaning to your problem.

Here is a great site you can go to and read all about the codes, and in most cases, get a detailed description of what they are telling the technition in the way of a repair:


http://www.obd-codes.com/search/

You can also Google them: it's as simple as just typing in the trouble code at the Google box, then start reading.

eacdabnow

I had the exact same problem- codes and all. First I had the throttle body replaced and the system cleaned... same problem. The dealer was in disbelief, after four days of investigation they came up with this one. The front main seal had a tiny leak which was dripping on the crank shaft position senor which inturn was causing the computer to think the motor was not running and shut if off. Giving the low oil pressure in the code center. Good luck this little problem cost me $900.00 bucks and it was only that cheap because I argued with the dealer about not being able to fix the problem the first time.