Greetings all -

First I would like to apologize if any of these questions have been answered before.

I am hoping that all these symptoms are of one source (I know.. wishful thinking), but I hoping also that someone here can help.

04 F150 SCAB 5.4 60k

First off - I have cleaned my MAP sensor..somewhat. I have Seafomed. I do not use E10 gas, maintain regular oil changes and service. I have not, however, changed my plugs or wires.

Symptom one: Rough idle in drive or park. The rough idle is sometimes mitigated by taking foot off of break...vacuum?

Symptom two: Slight engine shutter (like it could die) when coming to a stop (around 5 to 0 mph).

Symptom three: Loud **** lifter rattle upon start up...sometimes. I use only Motorcraft oil and filters.

Symptom four: pre-ignition rattle while driving. This is accompanied with upper engine "flutter" sound.

Engine starts fine - Does not smoke - Has never died on me *knock on wood* - Is responsive - Does not lack power.

I am hoping there is some magic sensor or some kind of singular something that can be done. This did seem to suddenly start all at once.

Any advice will be GREATLY appreciated!

Thank you,

Bug.

 

Throttle body... clean it or replace it.

 

I was considering that but didnt know what I may be getting into. I know my way around a wrench pretty well, but have never taken a TB off a/my truck.

I assume the TB is ported and that the ports get clogged? Obviously the best cleaning method is to remove and either blast it with TB cleaner or soak it.. but is there any benefit to spraying cleaner into the TB while the engine is running?

Bug

 

unplug the 2 wiring harnesses and remove your stock air box

unbolt the 4 10mm bolts

remove TB from the truck


clean using alcohol

let it dry


reverse the procedure. torque the TB bolts to 8 ft-lbs


very easy, and you aren't going to break anything. just don't let any dirt get in there

 

Thanks! i'll give it a try this evening and let ya know!

 

Well... followed your instructions to the letter...got it all nice and shinny like new, but same results. I am in the process of resetting the PCM just in case that is needed.

One thing that I noticed..another symptom if you will...is that when revving to 1500 rpm in drive, the engine shutters somewhat. When I rev over that (2k or so), as it comes down and passes 1500 rpm I can feel it shutter.

Perhaps a loose or broken injector?

 

take it to the dealership and ask if they can do the latest tune downloads for you truck.

what kind of gasoline do you use, what brand? what octane?

 

might want to change the feul filter to if you havent, might be a cheap fix

 

Sounds more serious like a weak coil or clogged injectors.

 

another good idea....and even if it isn't the culprit, it should be done every 15,000 to 30,000 miles


$15 for the filter
$10 for the fuel / ac line disconnect tool (if you don't already have it)


so about $25 at most to do yourself in the driveway. you would be very surprised at how much a dirty fuel filter can mess up your truck

here is an excellent How To on changing your filter
http://www.ford-trucks.com/article/i...0_Pickups.html

 

Thanks all -

I am using 87 oct - no ethanol. Unfortunately, there are few name brand stores to purchase "100% gas" here...most are of the "Beer - Ice - Bread - Cigs" variety..

Changed my fuel filter approx. 6k ago.

About the TB... I did notice that it would not close completely after I cleaned it (or even before I cleaned it) ..without pushing it closed. It wasnt opened much, but still open (unlike the old carb / choke that slammed shut).

I am considering replacing at least two of the O2 sensors (at $45 each gah!) and see if that helps even though there are no codes. I am also considering replacing the MAP sensor and the TBP sensor.