I know I have read about engine knock before and how the dealers say that a little is fine. My 5.4 in my 2001 Screw knocks on acceleration PERIOD! If I'm pulling a trailer or am going uphill it's worse. Has anyone had anything done by a dealer about this such as adjusting timing, replacing plugs, etc?

 

Hey dirvin,

I think the timing is automatically controlled by the emisions program code in the engine computer, not 100% sure though. I would be looking at the gas you buy and where you get it from. Do you always buy from the same station, do you always buy 87 octane, have you tried higher octane from the same station, have you tried 87 octane from a different station? Also, some stations that are less reputable tend to be sloppy with keeping their storage tanks cleared of water and other contaminants.

If your truck is a 2001, then you shouldn't need spark plugs for a long time, even if you drive a lot. Ignition systems in late model cars don't require the regular attention that older cars used to require.

If I were you, I'd be looking real close at my fuel supply. Get a clear jug and put some in it and inspect it visually as well as smell it. If it smells old, then that'd cause you to knock under acceleration for sure. Look for water in the bottom of the jug and other trash that might be in there too. If the gas doesn't knock you down when you sniff it, then it might be old or just poor quality. I'm just guessing so you might check with some other folks that buy gas from the station you frequent the most.

You might have some other legitimate engine issue, I'm just saying it's pretty rare these days with computerized engine controls and emissions systems that are required to meet stringent federal requirements in addition to enableing us to get higher fuel mileage and more power at the same time.

My $0.02

DaveMan

 

I agree.
Definately try a different source for gas. I use the cheapest GAS I can find in my Screw and only one place around here gives me any problems. Its a a Superpumper(Mobile Gas) and every time I fill up there my engine knocks( So, obviously I don't fill up there anymore).
What octane are you using?
The lowest we have here is 87 but I've been through places that have as low as 85.
Once, I was driving a brand new Motorhome with a Ford V-10 and I wasn't paying attention and I filled it up with 85 and the thing knocked constantly and lost all power whatsoever. I had to floor it to make it up hills at 45 that I was previously letting the cruise control handle at 75! Once the engine starts knocking, the computer retards the timing but it sounds like yours is either not retarding correctly(knock sensor not working) or it has reached the maximum "retard" level.

 

I have had problems with this too. I took mine in to the dealer and they updated the version of the software in the computer. My screw was built in Nov. 2000.

It seemed better after the update. I don't notice it much anymore on acceleration. I have only had two occasions to tow since the update. Once in Sept and last week. In Sept it was there constantly. I filled up on Exxon. Last week I didn't notice it.

I would describe it as light pinging. Not really a hard engine knock.

I have stopped using gas from a mobile station. Don't really know if there is any correlation though.

I do feel it is completely unacceptable. I haven't had to put up with spark knocking on my other vehicles and don't think I should have to on a brand new truck.

 

Thanks everyone..I have tried different octanes at different stations and still the same problem. I am taking it in for the 30,000 mile check tomorrow. I will ask about the software update. Don't know if these guys down here will know what I'm talking about. It seems that I keep them informed on the happenings off of the web and sites like this.

 

It is true that the ignition timing is controlled electronically, but it can also be retarded by your dealer. The technician can quickly connect his service tool to your truck and set what is called the OCTANE ADJUST setting in your PCM (powertrain control module). This should retard your timing about 3-4 degrees.

The down side of this is that it will ALWAYS be retarded, regardless of whether or not you are towing anything. Before you have them do this, they should make sure that your knock sensor is indeed working properly.

If you get your OCTANE ADJUST setting installed and it still knocks unacceptably, the base engine needs to be looked at in more detail, as well as the fuel system.

 

Just got my Screw back from the dealer. They "reloaded" the software in the computer and it's running better than it ever had. Don't know if this will help mileage also. I don't drive like an old man...I like to get to the speed limit or 10 or so miles over in a hurry and I run around 13.5-14 in town and the best I've ever done on the highway is 17.6. I work with a guy that has the 2001 Supercab with the 5.4 and he runs around 15 in town and 21-24 on the highway. We'll see....He drives worse than I do....
Thanks again.

 

21 - 24 mpg & 5.4L Ford. NNNNNNN no! He's yankin' your chain.

TS