Oil leak revisited

khwilson · 11-05-2006, 10:01 AM

OK.. I found the location of the oil leak. It is coming from the oil pressure sending unit on the top rear of the engine. However, it is coming past the threads of the adapter that receives the sending unit and screws into the block. I tried to take this adapter out but I cannot get it to break loose. It already rung off the extension I was using... so, my question is: If I get this thing off - which I will probably use my impact gun if I can find a 17mm 6-point socket - will I simply need to seal the threads with some teflon tape and screw it right back into the block?

Thanks in advance,

Jim Sims · 11-05-2006, 10:38 AM

Stop, before you damage/ruin your engine case! Read the below thread and the threads it references.

special tool? oil pressure sender..

khwilson · 11-05-2006, 04:50 PM

The oil pressure sending unit I am refering to isn't the one in the threads you seggested... it's the sending unit that is for the oil pressure light. It is mounted on the top rear of the engine right below the air flow meter (see attached picture). The one you're talking about is the one that is mounted on the front of the engine adjacent to the fan assembly.

I got the sending unit out of the car, the problem is that the adapter that bolts into the engine block (that the sending unit attaches to) is unbelievable tight. As tight as it is, oil still runs out through the threads and begins to drip on the ground within a minute of cranking the car.

Any advice...

Fishcop · Fishcop's Garage

You are right; it must come out to be repaired. Can you get a deep socket over the top?

Jim Sims · 11-05-2006, 05:07 PM

There is a good possibility the adapter wasn't installed with a sealing ring (see below thread) and was mistakenly over tightened in an attempt to get it to seal. Not good, as this may have distorted the threads in the case. You will need to get that adapter out and check for a seal ring. Can you see the adapter well enough to determine if a seal ring is in place?

Oil pressure switch adaptor base

mark911 · 01-21-2007, 07:04 AM

I seem to be having the same problem. any clue what the part number is on the adapter?

khwilson · 01-21-2007, 08:14 AM

I don't know what part number the adapter is since I didn't replace it. Mine turned out to be the crush washer between the adapter and the engine block. It doesn't look like the adapter comes off and mine was supremely tight, but as soon as it broke loose it came right off. If I remember correctly it was a 17mm wrench. Because I was so worried about messing up the adapter I went out and purchased a 1/2" drive impact socket and extension which I used with a breaker bar (NOT an impact wrench). Before that I broke one extension trying to get the adapter off and I wanted to make sure I didn't round the edges of the nut (an impact socket is 6-point and quite hefty).

You might as well replace the o-ring on the oil thermostat while you're back there. Don't let some of the post scare you - it is a very easy job to do as long as you don't actually have to see the job you're working on. If you can do it by feel, it shouldn't take more than 10 minutes.

Good luck!

Jim Sims · 01-21-2007, 08:38 AM

901-101-175-01-OEM; Reducer/Adapter Fitting for Oil Pressure Switch, 911/911 Turbo (1965-89) $9.20

I also doubt there is anything wrong with the adapter. The problem is likely elsewhere: leaking oil pressure switch or the metal sealing ring between the adapter and engine case is missing. Follow the referenced link in this thread to get the sealing ring part number. Note the pressure switch's sealing ring is trapped on the switch's inlet threads and therefore comes with the switch.

mark911 · 01-22-2007, 04:08 AM

thanks for the info. I will go ahead and replace the thermo ring as well.