I experienced the same situation when I installed my new 6.2 last summer. I was also told it was normal.
I have a question for you fellow merc. 6.2 owners.. Do you seem to have low oil pressure once the engine is warmed? I went all summer with the problem and inquired to merc and they gave me the 4psi minimum crap at idle. I am just not used to that and was wondering if anyone else was having the same situation? Thanks Dwight
I experienced the same situation when I installed my new 6.2 last summer. I was also told it was normal.
You must be using a multi-grade oil or synthetic - right? Try using a sae 40w or the merc 25-40
I will try a straight 40 in the spring to see what happens. I thought about replacing oil pump with a high volume and see if it helped but, it is alot of work to do it. Thanks for the replies Dwight
Whitey,
I use 50wt Valvoline Racing Oil. Works great but you must remember that warm up does not mean idle to the wake buoy then WOT. 50wt racing should bring up the pressure.
I will try in the spring, Why do you suppose mercruiser set the pressure so low?
I have this problem with a 383 motor I just built. When investigating this to see what may be causing it I found the oil filter was so hot you could not hold onto it. While the oil is cool the oil pressure stays around 40lbs then when it gets hot it drops off to about 10-12lbs. This worries me that the oil is to hot to do its job fully. I am going to install an oil cooler in the spring before I run it any more. You guys may check your oil temp. as well to see if it is getting hot and causing your press. to drop off.
I would make sure that using an oil other than whats recomended won't create a warranty problem down the road. What about installing an external oil cooler? Cooler oil=higher viscosity?
Can you guys give me a direction to an oil cooler application. I know the 6.2s do not have them and I thought that I would love to install, I am not sure what type or brand would work best. Also I am considering some exhaust what are you guys running? Do you guys know if bbc exhaust risers can fit on the sbc manifolds? Thanks Dwight
It is a problem, theres no oil cooler, the motor only has a 4qt oil pan, you can do the math. I've seen the 4psi in the manual, what the hell? At 5200rpm, 4psi is not enough psi, especially under a long sustained throttle period.
Note that we had a customer with dual motors that ruan 14lbs. of boost, 38 total timing, 6200 rpm for long periods with stock bottom end, stock pistons, etc but the few things that were changed was the pan (10qt Olson) and a oil cooler from Rex Marine, never had oil psi problems!
Dustin