Re: 525 efi oil pressure loss?
 

I too prefer a bit cooler running temp myself. Engines fluid viscosities stay where they should easier & the combustion chambers are les likley to have detonation. :) Jamie / Lakeside

Re: 525 efi oil pressure loss?
 

I dont know what nmanual you are looking at but merc this is out of the mers 525 service manual

Re: 525 efi oil pressure loss?
 

I don't have a scanner to show you but it says on page 34 of my mercury racing , operation, maintenance and warranty manual. Do not use, straight weight oils, non-detergent oils, oils containing solid additives, multi-viscosity oils other than the ones recommended or low quality oils. The only oil it says to use is marine engine oil 25-40

Re: 525 efi oil pressure loss?
 

I agree 25 40 is the best but what I posted is from the 525 merc service manual straight from merc

Re: 525 efi oil pressure loss?
 

My manuals came with my boat from eliminator. The print date on the manual is 2002. Maybe you have a revised issue.

Re: 525 efi oil pressure loss?
 

Brand new impellors both sides. What else could it be?

Re: 525 efi oil pressure loss?
 

2005 42 Executioner, 525 EFI's, Synthetic oil 40W, Fresh oil/filters (merc racing), 140 hrs TT on all. 3 hrs on oil/filters and impellers.

Many thanks

Re: 525 efi oil pressure loss?
 

I just had this happen to me also, I found the oil pick up had fallen out of the oil pump for some reason. Replaced the punp and had the pick up brazed on the new pump. $100.00 repair, however it did take a whole weekend to get the motor out and back in :mad: What I had done was just changed the oil and took the boat to the lake for a weekend with the family. I noticed that my oil temps were kind of high and was concerned about that so I was really watching everything closely. As oil started to fill all of the lines from the coolers and filters I started to see my preassure start to sipke and drop. The water was rough and I can only assume that as the pan oil was filling the voids and the boat rocked the pump itself would hit oil and spike the pressure and then come out of the oil and drop pressure. Got the boat back to the trailer and pulled the filter off and it was about half full at best. I put a bucket under the filter housing and cranked the engine over and it spit out no oil at all. Talk about a close call, while your filter is probably the cause of your problem I just thought I would share my problem with you.