mercruiser, high oil pressure?

adiesraceboat · 02-08-2011, 10:57 AM

hi all, not used my boat over the winter took it out the other day and oil pressure was reading high, from 40 ticking over and upto 80 as i tried to get on plane. oil and filter were changed last year. have since changed oil filter again but still the same problem.
i heard could be pressure relife valve, is that the next best thing to check? if so where can i find it and what do i need to do? any diagrams on line to help?

cheers.

Matt · 02-08-2011, 02:08 PM

If you've already changed the filter, then I'd be putting a mechanical gauge on temporarily to double check the readings.

pro-rig · 02-08-2011, 04:13 PM

Dont rely on the gauge readings as senders can play up, as matt says do a mechaniacal oil pressure test.

adiesraceboat · 02-08-2011, 08:37 PM

where can i get a gauge to fit on? what type? where to i conect it to? will it conect where the gauge on the dash is, or more direct place to the engine?

cheers guys

Tony Davis · 02-08-2011, 09:22 PM

the relief spring is inside the pump.

pro-rig · 03-08-2011, 08:04 AM

Remove the oil pressure sender and screw the mechanical gauge in its place.

Mike Bontoft · 04-08-2011, 08:38 AM

What did the oil pressure normally run at ? And what was the weight of the new oil. If the oil is a heavy weight and cold all the excess oil will have a harder time getting through the reliefe valve and port, you'll see high oil pressure until things warm up. Like everyone is saying check the sender first with a mechanical gauge. Connect the gauge directly at the engine, depending on the engine model the sender could be mounted in a few different places but usually directly on the engine block, the senders are cylindrical (about 1 1/2"dia. and 1 1/2" long) with a small hex at the base and a wire terminal on top. Unscrew it only by the hex not body and plumb in the correct fittings to attach a gauge. I am on the island and have a gauge if you need one.
Mike

adiesraceboat · 08-08-2011, 09:46 AM

Hi mike, cheers for the offer very kind of you, think its best if i just get a marine engineer to check it out for me, as they already have the gauges and know far better than me on how and where to fit. will try get it looked at tues or wens fingers crossed.