I have a combo Oil Temp/Oil Pressure gauge from a 911 installed in my 914/6 (2.7) and this gauge worked fine until the other day when I removed it to replace some bulbs... upon reinstall it pegged all the way up to max and stays there all the time now. This happened when I first installed it about a year ago, and it fixed itself... I had posted a similar thread back then and someone wrote this:

QUOTE

Most likely it was a wire connection or one of the oil pressure relief valves was stuck and finally released. I've had it happen in a type 1 race engine before.

My question is, where is the oil pressure relief valve at? Is it in (or part of) the sending unit that mounts to the engine or is it internal to the engine?

Doug C

There was a thread here that said reversed wiring would make
the oil pressure gauge peg high.

bb

Check the wiring. If it reversed or disconnected from the sender it will peg the gauge.

"G" stands for "sending unit" and *NOT* "ground" ... easy to mix up the wires ...
Andy

my aftermarket VDO oil presure guage, when not hooked up to the sender, once energized will peg to max. Double check your connections.

I've check those connections so many times already, that I gave up and posted this thread.. I've tried them everyway possible. When I reverse them from the correct arraingment the needle doesn't move from it's resting (key off) position. I will double check that I'm connected at the sender, but since it was fine before removing the gauge for bulb replacement - makes me think the gauge internals are whacked.. Has anyone opened one up? Maybe there is a connection inside that's has a bad connection. Thanks for the suggestons guys.

Doug C

Same problem;haven't had time to get back into the wiring, but I'ed like to know how you resolve it. Senders ok- I have it hooked to a VDO

Is the wire disconnected somewhere else? Say, at the plug on top of the center tunnel (where the center console wiring harness would plug in), or back at the engine? You might have tugged on the wire, disconnecting it somewhere. Measure the resistance from the end of the sender wire to ground; it will likely read infinite (or no connection, or ERR, or similar). Correct the "air gap" (i.e., plug in what got unplugged!) and it should work.

--DD