258 Oil pump change out

frhrwa

New member
I'm only getting 20lbs or less oil pressure, has anyone put a high output oil pump in there rig? if so, what type, and what results did you get? thanks..
 

High volume pumps are good. High pressure pumps are a waste of money. Remember oil pressure is the product of clearances in the engine. The engine is basically a controlled leak. So if you had 20psi before you will prob have 20 psi later unless the pump was completely worn out. I would put a service Gauge on it and verify your readings then go from there. Hoping all is good in the engine then a pump replacement may help as they are known to wear out I would opt for a high quality melling replacement.
 
High volume pumps are good. High pressure pumps are a waste of money. Remember oil pressure is the product of clearances in the engine. The engine is basically a controlled leak. So if you had 20psi before you will prob have 20 psi later unless the pump was completely worn out. I would put a service Gauge on it and verify your readings then go from there. Hoping all is good in the engine then a pump replacement may help as they are known to wear out I would opt for a high quality melling replacement.
so, by high volume, is melling a brand name? or type? thanks.. I can put a manual oil guage on to monitor the pressure just to double check it.. actually would rather have manual guages anyway... never did like electric sending units
 
Melling is the brand. I run high volume in all mine. It will put a slight amount more drag on your distributor so make sure your dist gear is in good Shape.
 

Is the melling readily available at parts houses like AutoZone or Napa, or ? what type oil do you use? Ive been running Rotella
 
Should be. I use 530 winter 10-30 summer. I don't bother with synthetic last one I tried to switch over the motor started knocking the next day.
 

i think my engine has a high volume pump in it. it idles at around 40 psi and runs on the highway up above 60 to 70psi. since my engine has been redone recently (i am not sure exactly when, i bought it with the engine already done and the guy i got it from didn;t know) and it had other good upgrades done, i think they did a high volume pump too
 
When I had my 4.0 rebuilt, the mechanic talked me out of going with HO oil pump because of the extra wear on the distributor. He told me that a minimum of 10 lbs of oil pressure for every 1,000 RPM is all that engine needs to be lubed properly.
 
That's right. High volume pumps have been found to have an issue over the past couple years, The slot for the dist drive wasn't cut deep enough and the upward pressure on the dist wipes out the cam gear and can destroy the pump at the same time. Check endplay!
 
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