Oil pressure and temp issues

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Norm Miller
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Re: Oil pressure and temp issues

#31 Post by Norm Miller » Sat Aug 03, 2019 7:17 pm

In your photo it appears the knurled nut on the sender is touching the sheet metal over #4 cylinder.
If it's grounded it won't work.
 

Brad Ripley
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Re: Oil pressure and temp issues

#32 Post by Brad Ripley » Mon Aug 05, 2019 12:03 pm

Greg, the sender in your photos of July 11th according to the markings were of a sender which must be used with a re-calibrated gauge. If your gauge has been rebuilt and therefore recalibrated, then the sender with a threaded stud (shown in your last photo) is the wrong one.

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Re: Oil pressure and temp issues

#33 Post by Greg Spreeman » Thu Aug 08, 2019 7:15 pm

Hey Guys,

Sorry for the recent silence. My mother-in-law passed away in March which rocked the family. Now, just last week, her husband, my father-in-law passed away. I guess to complete the old saying of, "things come in threes...", my mother passed away the first week of December. Not a good year. In any case, getting back to the car issue, North Hollywood rebuilt the temp gauge so I called them and they sent me a new temp sender. I also purchased a decade box and, with the instructions in a post above, I'll try to see what she is doing. I guess after the decade box to measure resistance and a multimeter to measure what his happening at the sensor, I'll have a better idea of what is happening. BTW, the Porsche 996 ran a bit warm today so, when I got home, popped open the rear deck and saw that the coolant level was low. Poured in some more antifreeze and noticed it ran right on to the garage floor. Hoping it's just the reservoir.

"And the hits just keep coming"

Best, Greg
Greg Spreeman
1965 356SC Coupe
1964 356C Sunroof Coupe

Greg Spreeman
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Re: Oil pressure and temp issues

#34 Post by Greg Spreeman » Fri Aug 09, 2019 12:23 pm

Here is what I got with the decade box:
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Greg Spreeman
1965 356SC Coupe
1964 356C Sunroof Coupe

Greg Spreeman
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Re: Oil pressure and temp issues

#35 Post by Greg Spreeman » Fri Aug 09, 2019 12:24 pm

Here is another setting and the result
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Greg Spreeman
1965 356SC Coupe
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Wes Bender
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Re: Oil pressure and temp issues

#36 Post by Wes Bender » Sun Aug 11, 2019 11:15 am

I hesitate to muddy the waters, but I've got to ask the question. When you run the engine and get it up to normal temperature, is the oil filter canister getting hot to the touch? If it isn't, something is blocking either the restrictor hole in the junction block or the one in the filter housing standpipe. If either of these is blocked, your oil temperature sensor will only see ambient temperature and will read lower than it should.
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Re: Oil pressure and temp issues

#37 Post by Greg Spreeman » Sun Aug 11, 2019 8:36 pm

I am bypassing the canister and have the full flow system. I accidentally left the temp sensor out and started up the car a few days ago and ended up lubricating my entire engine bay. So, I am definitely seeing oil running through the system.
Greg Spreeman
1965 356SC Coupe
1964 356C Sunroof Coupe

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Bill Tate
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Re: Oil pressure and temp issues

#38 Post by Bill Tate » Sun Aug 11, 2019 9:54 pm

Greg, If you have blocked flow through the bypass filter you will have pressure at the temp sensor but no flow. The temp would be via conduction rather than by the flow of hot oil over the sender. You need flow to reflect temp of oil exiting the oil pump. Can you open flow to the bypass filter and recheck temp reading? KTF
Bill Tate
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Re: Oil pressure and temp issues

#39 Post by Wes Bender » Mon Aug 12, 2019 10:36 am

If you have eliminated the oil line that used to go from the junction block to the filter (and the second line from the filter to the case), I think we've found the problem. As Bill indicates and as I was alluding to above, you have to have a path from the junction block back to the case. The restrictor in the junction block will prevent excessive bleed-off of pressure. You need that flow across the sensor or your readings will be too low. Not just pressure at the junction block, but flow past the sensor. Do you have that flow?
Some days it just isn’t worth the hassle of chewing through the restraints......

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Re: Oil pressure and temp issues

#40 Post by Greg Spreeman » Fri Sep 06, 2019 11:24 am

Okay, so we continue with baby steps. I hooked up the oil canister again so oil should be flowing by the temp sensor. For the Hell of it I pulled the top off the canister after I ran the engine for about 10 minutes and the canister was still full of oil. I did this since the temp gauge was only showing about 100 degrees or a bit less but, a thermometer dropped into where the dipstick goes was showing closer to 150 degrees. With the engine off, shouldn't all of the oil drain out of the canister? I wouldn't think there would be a check valve in there any where though, I could be mistaken.
Greg Spreeman
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Wes Bender
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Re: Oil pressure and temp issues

#41 Post by Wes Bender » Fri Sep 06, 2019 12:52 pm

There is a small hole part way down the standpipe in the canister. The oil level can't drop below that hole. Depending upon how soon after shutting off the engine that you took the lid off, it may have not drained down very much. Was the oil hot in the canister? If it was only warm or was relatively cold, there is a partial restriction in the system somewhere.

Following a rebuild a few years ago, I installed a new filter in the canister. I had cleaned everything during the rebuild. After running the engine for about 20 minutes on its initial start-up for about 20 minutes, the canister was still cool to the touch. After removing the filter element, I found the remains of an insect plugging the hole in the standpipe. The bug had to have been in the filter for it to get into the hole. Oil had filled the canister before the bug found its way into the hole.
Some days it just isn’t worth the hassle of chewing through the restraints......

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Rudy Bernhard
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Re: Oil pressure and temp issues

#42 Post by Rudy Bernhard » Sun Sep 15, 2019 2:05 pm

Earlier in the discussion there was mention of using a thread sealer on the threads. The circuit is completed by the conduction of the sensor to the engine through the threads, for both temp and oil pressure. Do not use Teflon tape or a sealant on the threads of the block or the sensor. They can add resistance, or cause the circuit to be open.
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Dick Weiss
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Re: Oil pressure and temp issues

#43 Post by Dick Weiss » Sun Sep 15, 2019 5:46 pm

Greg,

I thought I asked (weeks ago) about the outlet fuel hose (on the pump) and where it is going downward?

Dick

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Re: Oil pressure and temp issues

#44 Post by Greg Spreeman » Sun Sep 15, 2019 8:45 pm

Okay, here is the update. New sensor, routed the oil to also pass through the canister, cleaned the hole in the canister...it works!!!!!!! Thanks everyone!
Greg Spreeman
1965 356SC Coupe
1964 356C Sunroof Coupe

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