F150XLTSUPERCREW2001

We have a 2001 4/6L XLT Supercrew F150 Auto-trans 88000 miles;

At any speed between 45 and 50 mph it seems like it jerks back and forth between 3rd and overdrive. It is fast and maybe around twice a second. I would guess that something is causing an engine miss however there is no miss at idle or if you are sitting still and rev the engine up. We have No codes come up.

If have been pushing the button to turn off overdrive. Of course the rpms jump from around 1500 to around 2000 rpm. It does it under all conditions between these speeds and all the time; flat road with no head wind or hills or etc.... I also noticed that the tach does seem to jump which tells me means that either it is a very slow response tach or the engine rpms are not changing during the jerking/jumping/shuttering ! It was not doing this before and just started a couple hundred miles ago. Any ideas on where to start ? ? ?

torkum

I would say you have a COP going bad [low grade misfire] and the PCM hasn't picked it up yet. Ford misfire monitors can be a little slow.

lagarre

I had a similar problem, also had no codes. For example, 40 to 60 mph and climbing a slight incline. As the truck starts slowing down it will start missing. The missing also seems to get worse after the engine has warmed up.

I changed all 8 COP's, problem is solved. My truck is a 2002, 4.6 with 93,000 miles on it, I figured the COP's were ready to be replaced anyways. I bought the COP's on E-bay for about $80 shipped to my door.

F150XLTSUPERCREW2001

Thanks for the recommendations guys. I will buy 8 new COPs and install them and report back.

torkum

Fill the boots up with dielectric grease

F150XLTSUPERCREW2001

I need to know if it is even possible for a driveway mechanic to replace the COPs on a 2001 4.6L Triton. With the hood up I reached 3 feet down into the engine compartment and I could tell that there is no way to replace them from the top. I have to guess that a jack and about 24 inches of lift is needed just to get under the truck however if I do this can I get to the COPs to replace them while laying on the ground under the truck? Help !

torkum

I would say by your observation of how to get to the COPs this is way beyond your skills . Take the truck to a shop and have it done.

F150XLTSUPERCREW2001

As a retired mechanical enginneer and experimental machinist I don't beleive I'll will have a problem and if I do I am sure my experience with what I call real automobiles (older than 1970) will serve me well. I have learned that these engines were designed by a nieve rocket scientist. Guess I'll replace these little ditties and move on. I sure appreciate the experience of those who turn wrenches on these space shuttles though. As an old school engine builder I have always stayed lightyears away from these crazy designes.


It's my wifes truck. My ride is a little older and a little more rad. A CJ-7 dune jumper with a small block chevy built to run a little sick. A 6 inch lift with gumbo 44's. Yea, I still get stuck now and then but the warn wench pulls her right out.

I hope that the fuel rail isn't in the way. Thanks for the input guys !

torkum

Are you still going to try to change the COPs laying on the ground?

rickapalooza

replase the boots first usually cures the prob u havin did 4 me n 3 others i know...with the highway speed issue.....ok cruisin but give a lil gas as long as it dont downshift bucks like a bronco...