Jerking Problem. With my ST, that is.

[travis baldwin]

Hey friends. Brand new to the ST world. Love my new truck just having a little problem I'd like to share with yall. Backround: Was given this truck by my cousins wife. He passed away and she had no need for it so I gladly took it off her hands. She knew nothing about the service history of the truck other than all his vehicles were regulary maintained.



2003 4.0L

154,000

2wd

automatic



Problem: While cruising from 45-70 MPH the truck seems to disengage?, causing it to jerk / pull very quickly. Its very intermittent. RPM's do not seem to change at all. At first I thought it was the transmision because the jerking/slipping seemed to be coming from the back, however, a little research proved it could be the engine. Sorry, but this is really all the information I have. I bought the car monday and have worked straight 12's so I havent had a chance to check fluids, filters, plugs etc..battery looks newer.



Another question, in this particular instance of not having any maintainence records, what parts should I consider replacing??? Whatever advice you have I am all ears.



Thanks in advance -- Travis

 

[Vic Sorlie]

I'd change out every fluid stem to stern - coolant to differential, plugs, plug wires, air filter, fuel filter, serpentine belt. I'd start with transmission; drop pan to change filter, and install a drain plug in the pan. See Maintenance section of Projects for an easy and inexpensive drain plug DIY. Visit an auto parts store or fast lube to see if there's any OBD codes stored. You can see a list of everything this car needs by using the Online Lookup at my website www.enduranceoil.net.

 

[Scott Tanner]

start with the plugs... they will cause the engine to buck at low rpm high load conditions

 

[swshawaii]

Check engine light or trouble codes?

 

[travis baldwin]

Thanks for the advice guys. No check engine light, taking AutoZone later for the things STanner recommended, they can check codes there correct?

 

[EddieS'04]

Go for wires along with the plugs. No need for fancy high dollar plugs. They help nonthing in our motors. Get the motorcraft or autolite platinums. You might consider spiral core wires. Less resitance than filiment type. Carry more energy to the plugs. Also 8mm spiral core wires will usualy last a life time.

 

[Robert Caffyn]

Does it have an electronic transmission? Could be the lock-up feature engaging/ disengaging. That would give a feeling of not being "connected". Start with fluid changes. Get a trans flush and filter change to get rid of ALL the old fluid. The rest of the above suggestions are right on as well. Bob