02 5.4L Engine Power issues when hot out side

[relentless85]

2002 Eddie Bauer 5.4L 2 wheel drive. I can't figure out if this is a trans issue or an engine issue. This only seems to occur when the temp outside is hot (over 90) degrees. My wife drove it this morning with the a/c on and it was about 75-80 this morning, no issues. When she drove it home and the temp outside was 95+, when taking off from a complete stop, it feels like there is less power coming from the engine, like you have to push on the gas pedal more just to get some power to come up to speed.

I don't feel the trans slipping, the engine recently had a tune up at 119,000 (motorcraft plugs, fuel filter, air filter) it now has 125,000 on it. It also had the fuel injectors cleaned at the dealer at 116K and new belt last week. Transmission flush and fill was done at 81K so it is ready for that.

When I put the belt on, i also cleaned the throttle body and MAF with the correct CRC cleaners.

I am stumped. Any suggestions as to why it fees like there is lack of power only when it is hot outside?

 

[rtbrjason]

Probably the clutch fan sucking up more power as it gets hotter. My 99 5.4 acts this way and is usually accompanied by a "jet engine" type noise on take off from a stop.

 

[relentless85]

I thought it was the fan clutch too but I don't hear the jet sound on take off. I found a tsb about taking it to the dealer to have them flash the computer to not pull timing when the computer senses hot air from the intake. I don't know if anyone has had this done? Did it help?

 

[bcmaxx]

I had it reflashed for the same problem, if you can monitor underhood temps. you will see the intake air charge temp is super high when it runs poor, sluggish , lack of power. Mine got a little better when I discovered the sensor was clocked wrong and airflow was not going through it properly. But ultimately was told this is a normal condition. "cold air intake" makes it much worse, as you are sucking hot engine air. I'd imagine if you could move the sensor towards the air inlet near fenderwell it would help. I have a true sealed cold air intake on my jeep, I moved the air intake temp sensor from the intake manifold to just behind my air filter , made a world of noticeable difference