CCCP

I have just finished rebuilding my 85.5 na. When I removed the oil pressure sender I didn't index which wire went were. So today at start up I just guessed, before cranking I turned the key to the on position and the gauge read 0. I thought this meant it works. To prime the pump I pulled the spark plugs and cranked the engine for 15-20 secs at which point the gauge jumped up and pegged above 5 bar.

I thought this was all well and good and went ahead and started the car. She runs fine, but the gauge pegs above 5 upon start up, is this normal or should it be below that? By peg I mean it cannot go any higher. I know I have oil pressure, I pulled a hose from my oil cooler and oil came out immediatly after I cranked the engine just twice. I am just wondering if I have the sender wired up wrong or if it is possibly broken.

Techno Duck

Sounds normal to me, the oil pressure will drop off a little as the temperature of the oil rises. Let the car run for a few minutes and it should start up drop off.

CCCP

Right, that is how I remember it, but then again I havn't driven my 944 in 6 months and don't too well remember such details. What also startles me is when I cranked the engine at first just build pressure without the spark plugs installed, after 20 secs or so the oil pressure just shot up to the gauge limit, I was expecting it to be a slow gradual rise.

xsboost90

if they are backwards itll peg out over 5....

Techno Duck

BTW, i noticed this last weekend hooking the oil pressure sender wires back up. The sender used two different sized nuts, one 7mm and one 8mm. The ring terminals on the end of the wires were also both different sizes, so it was not possible to hook them up backwards. Im not sure if the old sender was the same way..but the new sender i put on was.

Van

That could also be a sign of a bad sending unit. The first 944 I bought had that problem -- the gauge read over 5 bar, so I thought all was good. Then, one day, it dawned on me that I'd NEVER seen it move. I replaced it, and the world was a better place.

Mighty Shilling

the oil pressure sender on my 924S went bad. it pegged over 5 and didn't move. I replaced it, and she's perfect again.

CCCP

Fixed, turns out I simply had the wires reversed. Apparently it still reads 0 with the key in on position. But pegs with any pressure....

Van

and after running for a while it drops down to 3 or 4?

CCCP

Yep, works perfectly now. Pics of the rebuild will be up in a few days in their own thread.

ehall

The oil pressure on my ex-girlfriend went above five. I replaced her. Her sister is better in the sack anyway.