I just got a '98 F150 w/ a/t and 4.2, and I am looking for any tips to increase reliabilty, aside from changing the 2 weak gaskets. The upper intake gasket looks remarkably thick, so I suspect it has beeen changed. Not sure about the one @ the timing cover, so that one goes.
It has 108K miles, runs excellent although the check engine light is on. A/C blows cold for 3 seconds then warms up, so I suspect I will be recharging it tonight. Other wise it is a great truck and I stole it.
I would like anyone with 2 cents to throw in to advise on things to watch for, things to fix early, or snything specific to this engine/transmission to make it reliable and help it last. I am coming from the venerable 300 I-6, so I respect bullet-proof.
Also, any tips to increase power like an EGR restrictor plate as is used in the 300 ?? K & N is on the way, and I have read the stickies before buying the thing. Thanks guys [ and ladies !].

 

As far as power goes:

https://www.ford-trucks.com/forums/s...d.php?t=237505

Tips for ya...I don't have many.
Run SeaFoam through it...that seems to help the truck tremedously. Every person that has used it has recommended it. If you really want to make you tranny smoother...I guess use some Royal Purple in the tranny...although I've never heard of that in an auto. With the K&N on the way, I guess you have the filter out of the way.

Have you done a systems check or anything? Like looked at the plugs and wires and all that fun stuff? Other than that...clean the injectors, TB, and other miscellaneous 'carbon build-up' applications.

Joe

 

Getting to all that this weekend. Every time I get a vehcile I go over all of that stuff if the seller can't document how recently things like filters, wires, plugs, etc were changed. Just went to Autozone for diag of ck engine. Nothing specific though- misfiriing cylinder, slow response of o2 sensor. They reset it and it has not come back on. It runs great too. I have injector clnr in it now, and I am going to run Seafoam through the intake tonight. I will be towing a boat with it, so I am likely going to put in a trans cooler.n The owenr's manual says the 4.2 with auto andf 3.55 is rated to 7200 lb tow capacity. Any experience with this ?? My 4.9 I-6 with the 3.08 was rated at only 5300 or so, and it struggled with my 4500 boat/trailer combo.

 

Don't sweat it. Our 4.2's can easily tow a bot/trailer combo all day. Just stay out of overdrive as much as possible.