Mine was doing the same thing, turn the ignition on...oil pressure goes up beyond 5, to the top. Stays there. No amount of tapping would move it.

Since I was on vacation and 2,000kms from home I tried the only thing I could at the time, removing the gauge and disconnecting the oil pressure side, blowing on it gently, saying a silent prayer, and replacing the connector. The first time worked for a day. The second time for an hour, the third time not at all...so as you can see from the pics, I replaced the sending unit and all is normal.

However...I still cannot explain why the gauge responded to the connector removal. Perhaps the signal was so weak from the sender that simply improving the connection at the gauge, however slightly, allowed the poor signal to be effective briefly?

Maybe a 'tap' is having a similar effect?

Jim

 

So it seems I would also need to replace the oil pressure sender on my 1995 993 C2.

When :
- engine is at idle,
- and vehicle is on an horizontal surface,
- and engine is hot (oil temperature needle is almost horizontal),
- oil level needle is almost horizontal (between 3 and 4 o'clock)
then, I usually read oil pressure is 2 bar.

But I was reading only 1 bar the other day. No trace of engine oil leaks on the floor. Engine noise is similar, no abnormal noise/

I checked oil level on the dipstick while engine is running at idle and engine is hot, it is right in the middle.

Then, I added a little bit of engine oil, the oil level increased a little but there was no impact on the oil pressure (still at 1bar).

When I rev the engine in neutral, I do see the oil pressure in the gauge increase (needle moving up). My mechanics thinks it is the oil pressure sender which is faulty.

I could not find how to replace it in the manual pdf I have (the chapter on lubrication is missing) so thanks jakfrost for creating this DIY.

I have questions regarding screwing the oil pressure sender onto the engine block (I suppose it is mounted on the engine block?) :
- what is the size of the spanner I need?
- what is the tightening torque?
- I don't need to put any product on the thread to make it properly sealed, right?

Thanks a lot!

 

With 10.5 quarts of oil already running through your engine … adding a bit of oil would not affect Oil Pressure other than overfilling.

Sure your Oil Pump is not crapping out?

 

My oil temperature remained very consistent to what I used to see - if my oil pump was starting to fail, I'd probably see an oil temperature increase?
Besides, I did not hear any abnormal noises compared to what I am used to hearing.

How could I check if the oil pump was starting to fail?

 

How could I check if the oil pump was starting to fail?[/QUOTE]

Well if my car had only 1 Bar of Oil Pressure that would be the first thing I would check if my Oil Level was 1/2 way up on the twist of my Oil Dipstick after ruling out the sending unit.

 

Yes, I checked and my oil level on the dipstick is about half way on the twist.

 

Who is dumb enough to put 12-13 qts in their motor?

 

10.5 quarts fat fingered that

 

So I did a bit more digging and it seems I will need a 24mm spanner to remove the oil pressure sender. When I fit the new one, does anyone knows what the tightening torque is? I read between 15 and 26lb-ft on this Pelican thread but this is not related to M64.05/06 engine so not sure which value of tightening torque should be applied?


Oil pressure sender 24mm nut

 

I have to ask, what weight oil are running?

 

Not really

 

Hi Jim,
I was unable to view your attached photo.
If it is the supplemental air injection valve, it has probably failed. The good news it can be replaced. On a 1995 OBD-1 car a failed valve will not trigger any emission-related OBD Fault code like the later cars nor will it influence any tailpipe emissions tests. It in no way impacts engine performance or durability. If you decide to replace it anyway as a good emissions citizen and it is badly corroded it can be stubborn to remove. On the below page it describes how to easily remove a badly corroded valve when all lesser methods seem to not break it loose:

https://993servicerepair.blogspot.co...horror-of.html

Hope this helps,
Andy

 

Forgot to add the link to the pelican page : http://forums.pelicanparts.com/porsc...que-specs.html


It is said maximum 35Nm i.e. 25lb-ft of torque but this is for the engine from a 84-87 911 :


Does anyone has a Bentley manual they could check what the torque tightening value is for the oil pressure sender to its connector? Would be greatly appreciated.
I ordered the Bentley manual but it won't arrive before next week and I need to drive the car in 2 days to a Porsche meeting :-D Many thanks

 

From the Bentley manual:

Oil pressure sensor to crankcase: 35Nm / 26 ft lb
Oil temperature sensor to crankcase: 20Nm / 15 ft lb

 

Thank you so much!!