No oil pressure, where to connect mech pressure gauge?
05-07-2013, 01:49 PM
#1
Rennlist Member
Thread Starter
No oil pressure, where to connect mech pressure gauge?
Hey all, its been a while.
For the past couple of months I've been pulling the fuel pump fuse and cranking the engine over build oil pressure before I fire the engine, which has always worked after 10 seconds or so, but as of yesterday the engine isn't making any oil pressure with this method (according to the dash gauge). I tried firing the engine twice but after 10 seconds of running and showing no pressure I killed it and have been hesitant to attempt that again. Today I pulled all the plugs out and was cranking it over for 15 seconds at a time but still didn't get anything. (Side note - that gear reduction starter I bought in a group buy on here a couple of years ago works awesome, so props to whoever it was that set that up)
I last drove the car a week and a half ago and it was running without any issues (and the week before that I did a 400mi trip in it), so I have no idea why its doing this now. I've had no problems starting it in far lower temperatures with the same oil, so I don't think the viscosity of the oil is an issue...
I'm going to rent a mechanical pressure gauge to hook up to see if my pressure sender has somehow died - what would be the best place to connect that to the engine? Remove the electric sender and connect it to that port? Or is there another port somewhere that would work well? Unfortunately I'm working with a limited selection of tools
Jumping ahead of myself, I know the oil pickups can sometimes get cracks in them, but if that was the case wouldn't that have caused some pressure issues when it was running?
As usual, thanks for any help!
Of course this is happening two days before I am supposed to drive it out to CA from CO for the ALMS race at Laguna Seca this weekend... (its been almost a year since the car has done something to **** me off, so I guess I was due
)
For the past couple of months I've been pulling the fuel pump fuse and cranking the engine over build oil pressure before I fire the engine, which has always worked after 10 seconds or so, but as of yesterday the engine isn't making any oil pressure with this method (according to the dash gauge). I tried firing the engine twice but after 10 seconds of running and showing no pressure I killed it and have been hesitant to attempt that again. Today I pulled all the plugs out and was cranking it over for 15 seconds at a time but still didn't get anything. (Side note - that gear reduction starter I bought in a group buy on here a couple of years ago works awesome, so props to whoever it was that set that up)
I last drove the car a week and a half ago and it was running without any issues (and the week before that I did a 400mi trip in it), so I have no idea why its doing this now. I've had no problems starting it in far lower temperatures with the same oil, so I don't think the viscosity of the oil is an issue...
I'm going to rent a mechanical pressure gauge to hook up to see if my pressure sender has somehow died - what would be the best place to connect that to the engine? Remove the electric sender and connect it to that port? Or is there another port somewhere that would work well? Unfortunately I'm working with a limited selection of tools
Jumping ahead of myself, I know the oil pickups can sometimes get cracks in them, but if that was the case wouldn't that have caused some pressure issues when it was running?
As usual, thanks for any help!
Of course this is happening two days before I am supposed to drive it out to CA from CO for the ALMS race at Laguna Seca this weekend... (its been almost a year since the car has done something to **** me off, so I guess I was due
)
05-07-2013, 02:06 PM
#2
Addict
Rennlist Member
Rennlist Member
There may be better ideas but punching an oil filter and threading in a hose barb should work. Add some JB weld. You could even prime the system with a mityvac or brake bleeder.
05-07-2013, 02:12 PM
#3
Rennlist Member
It will be messy but if you want a quick verification just pull off the oil filter and make sure the oil is getting that far. I know from personal experience that if you've developed a crack in your pickup such that the pump can't suck the oil up from the pan, nothing will come out of the oil filter fitting.
Assuming we are talking about the 951 in your signature, you should be able to work out a tee at one of the lines to the external oil cooler.
Assuming we are talking about the 951 in your signature, you should be able to work out a tee at one of the lines to the external oil cooler.
05-07-2013, 02:21 PM
#4
Another idea. Test your oil pressure sending unit to verify that it is working. If you reverse the terminals the gauge should peg on the high side. This would be an easy check.
05-08-2013, 08:32 PM
#5
Rennlist Member
Thread Starter
Sorry, forgot to mention that little detail about what the car is. It is on my 951.
I swapped the wire around on the pressure sensor and the reading on the gauge did not change, but when I held the two wires together the gauge pegged out at the max. Any idea what sort of resistance readings I should get from it if I test it with a multi-meter?
It looks like oil is flowing up into the cam housing, but I am unable to crank the engine over and watch into the cam tower at the same time to confirm if its flowing up or is just stationary in there.
Unfortunately none of the parts stores near Boulder have a pressure gauge to rent, much less a new pressure sender in stock. Jfrahm, it looks like you're in Boulder as well - have you (or anyone else) ever been to Carquip on Arapahoe?
Thanks for the suggestions so far.
I swapped the wire around on the pressure sensor and the reading on the gauge did not change, but when I held the two wires together the gauge pegged out at the max. Any idea what sort of resistance readings I should get from it if I test it with a multi-meter?
It looks like oil is flowing up into the cam housing, but I am unable to crank the engine over and watch into the cam tower at the same time to confirm if its flowing up or is just stationary in there.
Unfortunately none of the parts stores near Boulder have a pressure gauge to rent, much less a new pressure sender in stock. Jfrahm, it looks like you're in Boulder as well - have you (or anyone else) ever been to Carquip on Arapahoe?
Thanks for the suggestions so far.
