ho to tell if you have oil pressure if gauge doesn't work..... (1 Viewer)

[Bones]

so i hop into my 40 today after sitting idle for 2 weeks. 2 weeks ago she ran fine with all gauges working, have never had an issue with engine.

today i pump pedal, pull choke, turn key. she fires right up like she always has. i scan gauges an immediately notice i am showing no oil pressure. i shut her down. total time of maybe 30 seconds. while she was running, she sounded like she always does. the sending unit is connected, no oil on ground, no oil on engine. dip stick reads full. dizzy has not been removed recently and is fully seated.

is there a way to trouble shoot whether it is the oil pump vs a ground vs bad gauge, etc? in other words is there a simple way to tell if engine is getting oil?

thanks
andy

 

[BRShap]

I just went through the same thing. It's highly likely that the sending unit is bad. You could pull it and use a multimeter to check for continutiy in the wiring. If thats good I'd just order a new one. They're pretty inexpensive.

 

[brooklyn]

Same with me, changed sending unit and all was fine (had erratic readings). Got a bit of an oil bath when I took the old one off and tried to put the new one in -

 

[Solace in Solitude]

Pull the oil filler cap, start it up and see if you can see the rockers being oiled.

 

[Mace]

Unscrew the oil sender and add a mechanical gauge to it. That'll give you the most representative data point.

What year and motor?

 

[sggoat]

x-2 on the prev soln's.
Before you buy a new sender, pull the old one off and squirt carb/throttle body cleaner in the inlet hole-clean all that static gunk out of it-blow out with low pressure air, then reinstall. test it to see if the oil pressure comes back up. A secondary mechanical gauge is always good(it doesn't give you false readings due to stuff like grounds, or fuse issues)

 

[Bones]

thanks guys.

danny, i did as you said, and i did see oil on the rockers, but it did not look like anything new was getting up there. so i went to my second 40, both 1978 2f. started her up, and did looked in oil cap, saw the same thing, and she has oil pressure according to the gauge.

i removed the wire to the sending unit and it was beyond dirty, plus it has a crack in it. wire looks good though. i will tear into this weekend and remove the unit, clean it as per sggoat instructions and get back.

thanks as always gang.

andy

 

[sggoat]

thanks guys.

danny, i did as you said, and i did see oil on the rockers, but it did not look like anything new was getting up there. so i went to my second 40, both 1978 2f. started her up, and did looked in oil cap, saw the same thing, and she has oil pressure according to the gauge.

i removed the wire to the sending unit and it was beyond dirty, plus it has a crack in it. wire looks good though. i will tear into this weekend and remove the unit, clean it as per sggoat instructions and get back.

thanks as always gang.

andy

They don't splatter on the rockers---they dribble----

 

[Solace in Solitude]

I'd check the connector that slides over the sensor tab - it may simply not be making contact.

Mine fell off the sensor twice in the middle of nowhere - the second time, I fixed it.

 

[shawnfj40]

If you take that wire that goes to the oil pressure sender and touch it to ground you should see your oil gauge sweep. If the gauge is working you can either clean up your connections on the sender and check again or use a multi meter to check the sender to ground continuity while you start the motor. The sender works by varying the ground to your gauge.

 

[Bones]

shawn, i did as you said and nothing happened with the connector. but when a cut the connector off and just had bare wire the gauge swept over. so i think my issue is this. i cleaned up the bottom of the sending unit and touch wire to post and gauge swept. so from this i am concluding that the connector went bad somehow. i will fashion something new to attach it this weekend.

thanks again to all who replied. it is much appreciated.

andy

 

[Solace in Solitude]

They don't splatter on the rockers---they dribble----

shawn, i did as you said and nothing happened with the connector. but when a cut the connector off and just had bare wire the gauge swept over. so i think my issue is this. i cleaned up the bottom of the sending unit and touch wire to post and gauge swept. so from this i am concluding that the connector went bad somehow. i will fashion something new to attach it this weekend.

thanks again to all who replied. it is much appreciated.

andy

An insulated female spade connector fits fine.. just split the insulation on one side

 

[reddingcruiser]

Uh.....it's not rattling, knocking, overheating and seizing up!

Couldn't help myself.

 

[Bones]

Uh.....it's not rattling, knocking, overheating and seizing up!

Couldn't help myself.

thank you kind sir!!!

 

[shawnfj40]

Glad you found it. Congrats!

 

[65swb45]

Uh.....it's not rattling, knocking, overheating and seizing up!

Couldn't help myself.

Having flashbacks Dick?

 

[65swb45]

@StaleAle was intermittently loosing oil pressure on the way back from CMCC this year ...until he recrimped the connector on the sending unit.

 

[shawnfj40]

It sure gets your attention when it just drops to zero