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Posted by: SirAndy Dec 17 2007, 10:46 PM

this morning, i had to go to a meeting in SF and the car was running fine and all was good.

then, this evening i went to pick up my GF from work and when i started the car, the oil pressure went through the roof.

i have the 0-5 gauge and normally the pressure at idle is about ~2 and under full load close to 5.

now i'm getting 4-5 at idle and the needle hits the stop under load.

i checked on the oil cooler and thermostat, both work fine, supply and return line get hot/warm, so the oil is circulating in the lines.
they engine sounds normal and i don't see any oil squirting out of the block anywhere.

anyone know what could be wrong?
Andy

PS: the motor is a '95 3.6L from a 993 ...

Posted by: jimtab Dec 18 2007, 12:15 AM

Andy, could it be the sender? I mean if everything else seems to be ok and it's running fine, I'd be suspicious of the sender/sender connection....just my .02....and worth every penny.

Posted by: Dr. Roger Dec 18 2007, 12:52 AM

U screw with the bypass/pressure release spring valve?
Let's hope its the gauge...

Posted by: Mugs914 Dec 18 2007, 01:14 AM

Yeah, I was thinking the same thing. Check the pressure relief pistons and springs in the case. If one gets stuck in the bore it could send the pressure to the moon...

Posted by: SirAndy Dec 18 2007, 12:03 PM

same thing today ... i didn't touch anything on the motor. it all started when it started raining. coincidence? my motor is exposed to the elements, maybe the wire is shorting out due to the rain ...

Andy

Posted by: SirAndy Dec 19 2007, 07:09 PM

Mystery solved!

turns out, i was right about the rain. the sending unit on top of the engine block is exposed to the elements and the moisture from the recent rain storms was shorting out the pressure connector to the engine block.

after a day without rain and a nice drive to warm up and dry out things, everything is back to normal ...


now, all i need is to find some sort of rubber boot to cover the sender ...
Andy

Posted by: Grngoat Dec 20 2007, 01:37 AM

Just slightly off topic, but what sending unit are you using? I have a 5 bar gauge out of a 911 SC, but am still using the stock 993 sending unit which I understand to be calibrated for 10 bars. So the oil pressure reads double. Basically, the needle is pegged the instant the motor starts, so it acts more like an idiot light than a gauge. Have you fixed this somehow?

Posted by: SirAndy Dec 20 2007, 01:43 AM

yes, i got a stock 993 gauge ...

which works very well with the stock 993 sending unit.

the 993 sending unit is 5 bar, the earlier 911 sending units are 10 bar. i tried to use a early 911 gauge with the 5 bar range, but it never worked right. so i went and got the 993 gauge ...

now i have the correct oiltemp, oilpressure and check engine light all in one gauge. plus, i used some of the other "spare" warning lights to hook up additional "idiot" lights ...
Andy

Posted by: Grngoat Dec 20 2007, 01:51 AM

That's right, I remember seeing pics of your gauges before. That probably would have been easier, but I've spend enough money on the gauges, I'm not changing now!

Yeah, I need to find a 10 bar sender. That makes more sense when I think about the math. I've got the right sender for the temp gauge, check engine light is mounted in the console. Well, it's laying loose in the console and I'm going to mount it one day, but you get the idea.

Thanks.

Posted by: sww914 Dec 20 2007, 02:01 AM

Here's one


Attached image(s)

Posted by: purple Dec 20 2007, 06:58 AM

What's bad about the oil pressure going really high?

Posted by: mudfoot76 Dec 20 2007, 12:40 PM

If part of the system is blocked, then either oil isn't getting to parts that need to be oiled, or it is bypassing the cooler, or.....

I had bad pressure spike on my 2.0L and it literally blew out the oil filter. Puked oil all over the ground. I'd say that is bad.

But hopefully Andy's problem is something (relatively) simple and just the sender is bad...

Posted by: SLITS Dec 20 2007, 12:56 PM

Other than blowing the filter or oil cooler, excessively high oil pressure will pit the (used to be) babbit material on the crank, rod bearings and could lead to premature failure.

Posted by: GWN7 Dec 20 2007, 01:07 PM

What do you need?

I can do some very soft/flexible rubber

Posted by: r_towle Dec 20 2007, 01:15 PM

get the car umbrella cover.
The smaller one that covers the roof and engine lid.
Carry a can of the computer compressed air with you.
Blow it off when it rains.

Rich

Posted by: orange914 Dec 20 2007, 07:52 PM

or you canblow out oil galley plugs