2001 5.4L SuperCrew. Today in 93 degree weather, it was an absolute dog on acceleration after sitting in traffic after several lights. Once I had run for a while it was fine again.

Seems like I remember folks writing about this... I'd like more info before I head for the stealer... er... dealer.

 

Look where you live at! its only the humidty capitol of Texas. I live in Dallas and my truck has been running the same feels like I am towing a trailer or something.

 

I remember reading in the manual that an engine will auto switch to four cyls if it's overheated...
Could be a reason....

 

Autoswitch to 4 cyl? Never heard that... interesting.

RP

 

Do you happen to have one of those FIPK intake setups with the open element under the hood? If so, then you are just sucking in hotter then normal air and the result is a sluggish motor.

If not, then it could still be the hot air coming in from the fender (gotta be darn hot for that!!). I'd guess the humidty is not helping matters either.

 

The computer switches alternate cylinders off in the case of a loss of coolant. The injectors on those cylinders turn off and they just pump cool intake air to cool the motor. I think it's called "fail safe cooling", but you'd think that would only happen if in fact you lost all the coolant or part of it and your engine temperature went above a certain point.

We're you running the A/C on max as well, creating even hotter under-hood temperatures?

If you're really stuck in traffic put it in neutral and step on the gas a little to bring your rpm's up to 1200 or 1500 so the fan sucks more air through the rad. Switching to neutral (or park) also helps keep the tranny fluid temps down (if you're stopped anyhow).

Otherwise an open intake filter under the hood will do it too.

Have you got the "smaller" radiator when you should have the larger one?

 

Completely stock setup except large, 2.02" radiator installed, not abnormally hot, AC on, and guess what... today, I could not get it too repeat the process... I think the engine confuser... er... computer... can be a tad flaky... will have to see if it happens again.

 

I haven't had this problem with my 2001 5.4L Screw, but when I had my '98 Dodge Dakota 5.2L, the fan clutch would kick in on hot days with the A/C on and the truck not moving. The fan clutch put a big load on the motor until I got moving again, and it made a roaring noise. Once the fan clutch disengaged, the motor had its usual power back. Does the Ford 5.4L have a fan clutch?

 

Beastrider, I have the same problem and have been trying to get it fixed since last year. In hot weather, the truck turns into a dog, then it runs fine. It is not overheating. Ford has replaced my egr valve sensor twice and it will fix the problem tempoarily. I found a TSB listing thru this site for this very thing, but the dealer cant seem to match it up. I am very fustrated with this problem. Truck is a 01 screw with the 5.4 and stock aircleaner. If you find out anything, please let me know. Thanks.
Terry

 

I also live in Houston, and mine is a dog in summer too. Good old open K&N, . Anyway, once you get moving the underhood air cools off quite a bit. The main thing I hate, is that NOISY fan leaving a stop light in summer. It sounds like the truck should be lifting the front end off the ground from all that racket, LMAO!!!,,,,98


I'll be getting pulleys and electric fan very soon, hopefully that will help some.

 

I noticed my '01 Scab 5.4 did not like the 93 Shell when we had a 97* day here last week. I switched to the 93 Amoco(BP) and it ran quite a bit better. Ran better when it cooled off a day or so later also.

 

Probably just heat soak and high temps. On days like that, which we have also been having here, there is a lot of heat being generated.

If you aren't overheating then the truck is working harder to get rid of the heat. Even though coolant temp might stay steady the engine can reach a level of greater heat soak.

 

Yeh... but... the only thing is my 97 never did this... even in 106 degree weather pulling a trailer... this aint right... will try different gas and see if it makes any difference... otherwise, off to the dealer.

 

Beast, don't feel bad, I'm in the same boat with my '00 5.4L. When outside temps are below 90 and humidity is low, I don't have any problems and my engine seems to make excellent power with good throttle response. BUT get above 90 with higher humidity and it feels like I'm stuck in concrete.

Let us know if you find a cure.