hey guys i had a question about oil pressure in my engine, when im driving down the road i make about 25 lbs (i know its low) but when i let my foot off the gas and kinda coast the oil pressure shoots up to a little over 30ish its way more noticeable when the engine is cold, also what are yalls take on oil coolers? (the sandwich kind between the filter and the block)

  Disc Brakes are for Cowards         

My guess is worn main bearings.  Two things can happen.  First, the pistons are no longer being pushed down by the combustion, rather, drawn up by the suction created by the closed throttle, and secondly, the transmission is driving the crankshaft.  End result is, the crank is lifted closer to the oil holes, reducing the clearance for the oil to leak out.

I don't think an oil cooler will fix the problem, but may increase pressure because of a little thicker oil.  You can buy thicker oil and save the cost of the cooler.

John - "The Hoosier Hurricane"

thanks john i was thinking about using a heavier weight oil i'm using 10w30 with the zddp additive right now, how heavy would you recommend? i know that a rebuild is in order i plan to tear the entire car apart in about 6 months...

thanks -jason

  Disc Brakes are for Cowards         

Go to 20-50.

54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

20-50 thats some thick stuff would that hurt anything?

  Disc Brakes are for Cowards         

Shouldn't, but if your concerned go to 15-40 Rotella T (diesel). Ive been using 20-50 oil in a bunch of cars and never had an oil problem.

54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

okay cool i'll pick up some tomorrow if i get deisel oil do i need the zddp additive? i've read on here that desiel still has close to the amount that our engines require.

  Disc Brakes are for Cowards         

You shouldn't need the additive with oil viscosity 40 and higher. 15w40 and 20w50 should be fine. If in doubt about an oil, go to the manufacturer's website and look up the MSDS for the particular oil you are planning to use.


Lawrenceville, GA

Agree with John in that it sounds like worn main bearings.

Engine oil coolers are fine on trucks where excessive heat in the oil is being generated but can prolong engine warmup and increase engine wear on street driven engines.  For street driven engines, warmer oil is more efficient while also staying cleaner longer.

20W-50 oil is fine in a worn engine.  Like Charlie says, additional wear additives added to the oil are not necessary with any oil with a 40W or higher in its classification.

Lorena, Texas (South of Waco)

Jason,



If "driving down the road" means 2500 RPMs (automatic trans?) you are on the rule-of-thumb edge of minimum oil pressure (10#s for every 1000 RPM). If 20/50W doesn't bring it up, you might try tossing in a quart of Lucas viscosity expander with every oil change until you can arrange a rebuild. It seems more highly recommended than the average "snake oil".



What is your hot-idle pressure? The Lucas boosted mine 10#.

6 VOLTS/POS. GRD. NW INDIANA