Hi guys hoping get some input on my 99 f250 with the 5.4L

Love the truck except when pulling a trailer .. I kno just 5.4 but even with a "lighter" trailer (maybe 4,000lbs) ill have it to floor and motor be screaming but barely moving from wat I have read so far the lil 5.4 should be doin better then wat mine is ...

 

Is there any pinging or rattling noise from the exhaust while pulling?

 

No ... my exhaust was rattling all time but I cut out and ran duals ... i was having problems b4 the rattling began

 

Do you still have the stock cat? (catalytic converter)?

 

No they straight ... but ive had this problem from day one of owning the truck ... with stock exhaust it do same ... motor screaming but not speeding up like should ... im thinking something do with torque converter but hoping get opinions

 

But only when pulling a trailer

 

What are you comparing this to? A 5.4 in a SD is lacking power anyway. (Compared to the v10 and diesels) find another 5.4 and hook up a trailer to it?

I'm just saying, what are you basing it off of? Maybe everything is fine and that's just how it is.

 

Sounds to me like you have unrealistic expectations. You will be using wide-open-throttle frequently when towing something heavy, and there's nothing wrong with that. A larger engine would handle the load easier, but you're not hurting anything by putting your foot into it.

I don't think you have a problem. Your '99 is the only year that didn't get PI heads, so you are pushing all that weight down the road with only 235 HP. That's less than a modern minivan has, it's going to take some time getting up to speed.

 

I had an 06 5.4, which has more stock power, and felt the same way about that motor when towing. My trailers were definitely over 4k/lbs though. I think my rated max capacity was 9400lbs and I probably towed I the range of 5-7k. I felt that the motor had a "dead spot" between 2700-3500 rpms. It would make a lot of noise and not move(figuratively) until it passed 3500 rpms. This is for stop and go towing. I was towing around 7500-8000 on a highway ride that had lots of undulations and it was hard to keep it at speed and was constantly shifting. I just did not like the motor when towing or hauling.

I'm not sure what truck you have but looking at the towing guides for a 99 super cab 4x4 3.73 the max rating is 7400lbs. So 4k is over half the rated capacity. Anything higher and your closer to max which results in decreased performance.

http://hillerford.com/resource_library/RV_towing_guides/1999_towing_guide.pdf

 

Would a head swap help me any since its a 99 ?... and our company has a newer E250 van with the 5.4 and it pulls better then my truck ...

Im just hoping there nothing wrong with tranny or tc tht cause my problem (which wat I was thinking)

 

Yes the E250 will feel more powerful. It's lighter and has PI heads, so 255 HP instead of your 235.

You can put PI heads on your engine, that's a common thing to swap on some other vehicles that share these engines. You'd need heads and a new intake manifold.

 

miles on truck would help...expectations of a truck with 200k miles with abused service intervals would be different than a truck with 75K miles and current service records.

check your tranny fluid....is it red...brown..or black...does it smell like asphalt?

 

Tranny fluid is fresh .. there 145,xxx miles on truck

Wat year did they start the PI heads?

 

2000. Ya just missed it.

 

I towed trailers up to 7,500# with my '97 F-250 SC light duty truck with the 5.4L engine and 3.73 rear end until I sold it this year with 131,000 miles on it, and I never had to floor it to get necessary power out of it. It was a screamer, though.