Very hi oil pressure!

[Jay Laifman]

I think my 73.5 T now has terribly high oil pressure. At least that's what the gauge is reading: like 120+ psi. It didn't used to get this high. What has happened and is my car at risk if driven?

Here are some details though. A couple weeks ago, I changed the plugs, cap, rotor and air filter. It was running beautifully. But then on the way to work, the alternator light started coming on at low rpms and by the time I got to work, it was staying on and the car was running badly. On the way back home, I noticed the oil pressure gauge almost maxing out. I assumed that the problem with the alternator was causing electric problems for the WUR and the oil pressure gauge.

I replaced the alternator and now all is fine with the charging. But, when I drove it to work today, I saw that the oil pressure is still way up and it is still running a little off. Could the low power running driving to and from work (about 2 hours total), have caused a problem?

The oil pressure gauge reads around 18-21 on idle, but by around 3,000 rpm it's up to over 120 psi. It is not all the time. Sometimes it seems more normal. But then one time, it was holding at about 50 psi when I was at higher rpm and I felt like it should be higher.

Any thoughts or suggestions would be greatly appreciated.

[304065]

It's either the sender (potentially messed up by voltage issues) or the relief valve is sticking in the bore.

buy yourself some aluminum crush washers 18x24mm
remove pressure plug, the vertical one, that pops at 76.8 psi
if your engine stock you need the p74 or whatever tool to remove the screwdriver plug

[Jay Laifman]

Thanks. If it is the valve, is it dangerous or bad for the engine to be driven that way? Or just breaks down the oil faster?

[304065]

It flattens the bearings, kills power and blows seals.

[Jay Laifman]

Oh, no big deal then.


!!!!!!!!!!!!!!! Hopefully it's either the gauge or I caught it early enough and kept it low enough.

Thanks for your input.

[304065]

Here is everything I know about it:

http://forums.pelicanparts.com/911-e...ve-thread.html

[Jay Laifman]

That's a lot!

Thanks.

I'm assuming the engine has to be drained of oil before opening these, at least the vertical one. But, I've been meaning to change oil anyway. So I'll do both this weekend.

[cmcfaul]

At what temp does it do this? If the engine is cold, oil pressure will peg at 3,000 RPM's (normal). At operating temps it should go no higher than 60 and no lower than 10 (just off 0). A weak connection from the sensor or in route to the gage will cause high readings. If you disconnect the gage it pegs (the sensor pulls the needle down). Check the connections.

Chris

73 911 E

[Jay Laifman]

Hmm. I'll check this weekend too. Any idea if the oil pressure sender, which I seem to think is on the lower right rear of the engine, near the chain tensioner lines, if those wires run to the area where the VR is? I did switch the VR when my alternator failed. I wonder if I disturbed the wire there.

[Jay Laifman]

Well I did much of what I wanted to do today. I drained the oil, adjusted the valves, changed the filters, etc. I found the oil pressure relief valve. But, unless someone tells me otherwise, it looks like I can't get to it without taking off the exhaust. Agree?

So, I sprayed the nuts on the exhaust with a liquid wrench type of stuff. I'll leave that for another day.