Oil Pressure Question - RTH Needed

[1994Hewes]

So I left my office this evening after my '84 FJ60 sat in the lot all day and about 3 minutes in to a 5 minute drive, I noticed the oil pressure needle was essentially pinned at the top. I arrived at my destination and the truck sat for about an hour and I came back out and cranked it to find the gauge now down below the L (low), but not buried like it is when off. Temp gauge was just above C since I hadn't gone very far also.

I just had an oil change last week performed by a very good FJ60 mech. I am not much of a wrench, but I checked that the wire for the oil sending unit is connected as I saw in other threads (to the pin in the middle). Oil level is fine as well and no leaks or anything to be found.

Under the oil filler cap, how much oil should I see? It looks well lubed, but I don't actually see a pool of oil in there.

Do you think this is a sender/gauge issue and its actually safe to drive. At the moment I'm stranded trying to make sure I won't kill my smooth running 2F if I run it.

 

[gregnash]

Believe that is more of a sending unit issue. Check to ensure that your galley plug (between 5 and 6 cylinder right above the 5 cylinder spark plug) is still there and not weeping any oil or gone completely. Do a quick search on oil galley and to confirm the location.

Other than that look for some strange/large oil puddles or leaks underneath if you can.

 

[1994Hewes]

Galley plug is definitely still in place. Though I still need to do the fix. Local parts shop has a sending unit in stock for $7. May have to run there and find out.

 

[gregnash]

Does pressure gauge move as you revv the engine? What weight oil did you use on the recent change? I have heard tell of guys moving to synthetic with lighter weight oils have this happen. I went from whatever the PO was using (in cold weather) to a 5W30 and my needle moves from the top mark to the bottom mark from moving to idle respectively (and sometimes varies).

 

[1994Hewes]

No movement in gauge except for when it first cranks up. Not sure what he used on the oil change, but I know he always uses the same synthetic and has for a while. I did ground the gauge against the block while somebody sat and watched it move the needle sweep up the gauge, so I think that means the gauge is good. What about the oil level under the cap? What should that look like?

 

[1994Hewes]

So I replaced the oil sending unit with the one from O'reillys which looks nothing like the OEM unit. Turn the key to On and the gauge goes up to H. Crank the motor and it falls back down below L. Feels like the sending unit to me. Going to order an OEM unit tomorrow.

 

[gregnash]

You should not see any oil pooled in the valve train unless it has been running for a while and then it should be very very slight. Basically, everything should look wet in there, good and lubed, but that is pretty much it.

Yeah sounds like the sending unit is bad or maybe your gauge is going out?

 

[1994Hewes]

It's got to be one or the other. Everything sounds good at idle and running so things are getting lubed.


Thanks for the help gregnash!