Question-------------------------
Followup To
Question -
-------------------------
Followup To
Question -
I have now ran my truck with a new Fram TG-5 filter since my origional E-mail to you while watching my oil pressure closely with no further problems. On initial start-up, I notice a slightly elevated pressure which drops off to normal reading once engine is warmed up. As a further note, I had recently changed out the intake mainfold gaskets and possibly had dropped a minor piece of debris into the oil pan.
And now I have another question I hope you can assist me with. My fuel economy has slowly declined to around 12 to 13 mpg around town driving with approx 15 to 16 on the highway. Do you know any way to increase this relativelyinexpesively. As an aside, the truck has an aftermarket exhaust consisting of a twin 2-1/2 inch after cat system. Would I likely pickup some economy by dropping the pipe size back down to 2 or 2-1/4 inches? Thanks for your assitance in advance.
AnswerGlad to hear that the oil pressure is back to normal.
There is an inlet screen on the oil pump and any pieces of manifold gasket would not likely pass through it. In fact, if enough pieces got caught on the inlet screen you would have a low oil pressure problem from insufficient supply.
Exhaust tuning is a fine science. If you had true duals (no cat), you could apply paint to the head pipes from the exhaust manifolds to the mufflers. Running the engine would yield a point where the paint bubbles and a crossover pipe would need to be weld between the head pipes at that point.
With your cat-back system, the answer is not as clear.
I think your money would be better spent on making sure that the engine was in full tune (this includes checking all emission systems and note that a defective oxygen sensor can cause a drop in economy without making the engine run poorly) and that your cat and muffler(s) are not restricted. A vacuum gauge can be installed on the intake manifold and monitored for a drop in vacuum after starting the engine. This is not a drop asscoiated with opening the throttle, but a gradual drop after obtaining the initial vacuum reading at a idle. If vacuum drops off, there is likely a restriction in the exhaust.
