oil pressure sending unit question

scutly

Petty Officer 1st Class
Joined
Aug 20, 2009
Messages
368
is this a merc or sierra only part? or is there a "generic" 1/8" / 0-80 PSI small block GM sending unit i can pick up from the auto parts store? i was hoping to avoid paying $30 at the "boat store". watched my buddy drop $100 plus this afternoon for the cheap set of zincs, 2 quarts of drive lube and the pump for the quart bottle :eek:
 

boat127

Petty Officer 2nd Class
Joined
Apr 18, 2010
Messages
196
Re: oil pressure sending unit question

first off what are you working on year model s/n.
second what makes you think its the oil pressure sending unit
and you can get them from merc or sierra
 

scutly

Petty Officer 1st Class
Joined
Aug 20, 2009
Messages
368
Re: oil pressure sending unit question

first off what are you working on year model s/n.
second what makes you think its the oil pressure sending unit
and you can get them from merc or sierra

1994 merc 5.7 ser # OF 133662.

my gauge reads zero. i grounded the wire from the sending unit and my gauge pegged at 80 psi.

MERCURY MARINE pART # 815425T
or
MERCURY MARINE PART # 90806
or
Sierra International 18-5899 Marine Oil Pressure Sender

SIE-18-5899_lg.jpg
 

boat127

Petty Officer 2nd Class
Joined
Apr 18, 2010
Messages
196
Re: oil pressure sending unit question

one thing i would recommend is to hook in a mechanical gauge and confirm you do have oil pressure.
 

scutly

Petty Officer 1st Class
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Aug 20, 2009
Messages
368
Re: oil pressure sending unit question

cmon dude im WAY past all that. can you answer my question? or ya just bored?
 

boat127

Petty Officer 2nd Class
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Apr 18, 2010
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196
Re: oil pressure sending unit question

i would get the merc one but do as you wish
 

scutly

Petty Officer 1st Class
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Aug 20, 2009
Messages
368
Re: oil pressure sending unit question

don't get me wrong. if ya read any of my other posts you'll see im all for OEM "marine" parts when needed. i just don't want to come to find i spent $30 on something i could have got at pep boys for 10 bucks. if its marine grade only im cool with that. but i don't go to west marine to pay double for fan belts and spark plugs.
 

fivedawg

Recruit
Joined
May 3, 2010
Messages
3
Re: oil pressure sending unit question

my oil pressure gauge was not working, i removed the wire from what i thought was my oil pressure sender and turned the key , psi went pinned to 80 psi, replaced the wire and ran engine, psi never moved off 0 psi, i removed what i thought was my sender, and after research seem to be my oil pressure switch for the alarm, but was right on oil filter housing. now im confused if this is not my sender where could that be and is this my problem
 

scutly

Petty Officer 1st Class
Joined
Aug 20, 2009
Messages
368
Re: oil pressure sending unit question

my oil pressure gauge was not working, i removed the wire from what i thought was my oil pressure sender and turned the key , psi went pinned to 80 psi, replaced the wire and ran engine, psi never moved off 0 psi, i removed what i thought was my sender, and after research seem to be my oil pressure switch for the alarm, but was right on oil filter housing. now im confused if this is not my sender where could that be and is this my problem

on top of engine, in front of the distributor and a little off to the port (left) side is where i found mine. manual says to test it by removing wire and GROUND it. gauge should peg at 80. i ended up scoring a new quicksilver one on ebay for $10 :D
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: oil pressure sending unit question

...watched my buddy drop $100 plus this afternoon for the cheap set of zincs, 2 quarts of drive lube and the pump for the quart bottle :eek:

That's real cheap... Here (Australia), we'd pay around $400 for that lot.... I jest not!

Oh, as long as the sender is 33-240 ohms, buy it anywhere you like (I'd paint it to prevent corrosion if it, not OEM).

Chris....
 

fivedawg

Recruit
Joined
May 3, 2010
Messages
3
Re: oil pressure sending unit question

so then the paert i have must be my oil pressure switch for the alarm? possibly?? i have a mercrusier 5.0lx alpha one engine, the oil pressure sender is universal for all mercruiser engines correct?
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: oil pressure sending unit question

so then the paert i have must be my oil pressure switch for the alarm? possibly??

If it came from above the oil filter, it's a switch... There are 2 there (if it has an electric fuel pump), one for the alarm and the other for the fuel pump (if it's electric).

fivedawg said:
i have a mercrusier 5.0lx alpha one engine, the oil pressure sender is universal for all mercruiser engines correct?

Yep...

Chris.....
 
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