codydurr

ok so I have a 2004 fx4 with a 5.4 with 177k miles. I didn't notice this problem until I changed the plugs and cops. the problem seems to occur all throughout the rpm range but most prominently around 1750 rpms. its almost like the truck starts to bog down, even on flat ground and then all of a sudden has all the power it needs. I notice it more when towing my boat. I have 3.73's on 34'' nittos with an edge evo on lvl 2 and full dual exhaust from the manifolds back with only the from 2 cats as well as the gotts mod. Ive also changed all the filters. I reset the evo back to factory and did the computer reset and then loaded the tune back on and it seems to have made no difference. the motor sounds like a mac truck so I know the phasers need to be changed but when I had my 04 lariat(before it burnt to the ground) it sounded the same with more miles and ran like a champ. im lost here

Newfiedan

If it sounds like a mac truck the fan is not disengaging. Check it first then once that is done pressure wash out your radiator as that will help things run cooler. If it's plugged up then that will not help things.

codydurr

the fan disengages around 20 mph. I will wash the rad. out tomorrow and see if that helps. It was just odd that it started this after the plug and cop change.

Newfiedan

Could be coincidence, either way the "mac truck" sound is usually caused by the fan not disengaging but either way let us know how you make out. I know it can caused delayed shifts as well due to the drag on the engine rpm.

codydurr

Well I've cleaned the condenser as best I could with a garden hose.it seemed to help a small amount but today was fairly hot and it seemed to start doing it again.the previous owner the a k&n in it and it was so filthy I deemed it unwashable, thus I replaced it with a Fran and cleaned the maf. Could the throttle body being gunked up cause these symptoms? Could this possibly be related to the phasers being bad(noisy)? Also when the impg display on my edge dips I hear the engine start to bog and then out of nowhere it runs fine, until it does it again.this all happens about once a mile or so.also I've got a p0420 that keeps popping up

Especial86

iTrader: (1)

Are you getting any rattling from the cats at all?
It usually sounds like a heat shield is loose or a Ping pong ball in your exhaust..

Cleaning the throttle body might help out quite a bit.. You need to remove it to clean the underside with TB cleaner and a rag.. If its caked up real good then that could be your answer.

codydurr

I'll have to check the tb in the a.m.. I have not noticed a rattling from the cats but I've only got the front 2 left as the p.o. deleted the rears when he did the exhaust.

Especial86

iTrader: (1)

Did you do the plug change after you experienced some misfiring?
How many miles on the plugs installed now?
A misfire could have melted down a cat, which can restrict exhaust flow. Any big exhaust leak can also throw a p0420 code..

codydurr

Yes there was a pretty bad miss. I'm gonna check the tb and maybe out my longtubes on with some high flow cats. The 0420 code seems to pop up every3-4days

codydurr

I've got about 1500 miles on the new plugs and cops