oil pump replacement HELP my ST IS DEAD!!!

[TowTrac]

has anyone changed out an oil pump on a 2004 GEN 1 ST 4x4 auto. how hard was it???? any info would be greatly appreciated. I'm pretty mechanically inclined. I just changed out my water pump.

THANKS!!!!!!!!

 

[scott degroot]

What's up with the oil pump? Not a common failure item

 

[TowTrac]

well I really don't know if it is the pump. I have found zero threads on it as well, my pressure gage is acting up but I haven't replaced the sensor yet so I should do that first.

 

[Gavin Allan]

Your pressure gage is just an idiot light. It does not display anything relating to the actual oil pressure exept that you have a few psi to trip it if the needle is not at zero.

 

[Richard L]

You never said how the oil pressure gauge is "Acting Up", but...the oil pressure gauge on Gen-1 Sport Tracs is just an idiot light and the sending unit is known to be defective, especially when the weather gets cold. It sticks and shows no oil pressure, and a few minutes of idling the gauge will register normal pressure.



The idiot/gauge will jump to the normal operating range when the sending unit senses about 8 PSI of oil pressure. If the sending unit sticks, which is all too common, the gauge will show no oil pressure at start up and you will probably get a "Check Gauge" light. After a few minutes of idleing, the sending unit will unstick? and oil pressure will register on the gauge as normal.



The only solution is to replace the sending unit, or just ignore the gauge? I personally do not recommend ignoring the gauges, so I would opt to change the sending unit. My Sport Trac had the same problem, and the Sending unit was replaced by Ford under warranty, but it was only a few months old when it started acting up.



The alternative is to add an aftermarket mechanical or electronic oil pressure gauge that is a true gauge, and not an on/off idiot gauge.



...Rich

 

[Vic Sorlie]

I've never seen an oil pump failure in the 30+ cars I've owned, so have never attempted to replace one with engine in car. Getting access to it in a 4x4 Trac is going to be a major job, IMO. I recommend you check operation of yours with a direct pressure gauge before you take this on.

 

[TowTrac]

Thanks, all. I know my valves are shot, I didn't know if it was due to oil pump failure. I won't throw money at the pump then. now I'm contemplating if I should just do the valves, engine swap, or get rebuilt heads. Thanks again everyone

 

[Gavin Allan]

How do you know that your valves are shot?

What part of the valves are shot?

 

[Richard L]

towtrac,

As Gavin just asked, How do you know your valves are shot? How do you know it was caused by a bad oil pump. It sounds like you just made that leap without performing any real diagnostics to confirm your suspicions?



Early Sport Trac 4.0L engines are known to have a condition called Timing Chain Rattle caused by defective Timing Chain Tensioners. The noise is often described as a tapping or clattering sound that comes and goes especially when the engine is cold.



The early Sport Tracs were also known to have defective oil pressure sending units that caused erradic oil pressure gauge reading (does not really measure pressure just an on/off gauge)



I would advise you to get several professional diagnostic tests and opinions about what's wrong with your engine?



...Rich

 

[Steve Krusich]

Replace the oil pressure sensor. They are KNOWN to fail. That is your oil pressure explanation.