flickering oil pressure gauge

[BrokenMu]

Ok, so quick run down of what the motor has been through.

Blew up, rebuilt and running fine.
The re-conditioner lost my original oil pressure sender and I sourced one from another 4JB1 (unknown origin car) from the wreckers. This one did not have the sender wire attached to it, so I made my own cable and connected it to the appropriate receiver wire.

The motor was first filled with Penrite 15W50 semi-synthetic diesel oil.
On initial start-up after re-installing the motor, the gauge read perfectly.
After the first 100km's the oil was dropped and replaced by the re-conditioners "special oil" (unknown to me) and the gauge read 8kg at idle and dropped to 4kg when revved.

As of last night the motor has done 1000km's and the oil was dropped and replaced once again by fresh Penrite 15W50 semi-synthetic diesel oil and is still reading 8kg at idle and dropping to 4kg when revved.

any help is greatly appreciated.

Kind regards
Michael

[benny]

My 3.1 turbo does'nt hold on same reading either I thought this must have been normal, when I go up a big hill ( 10 mins) pressure drops right off but does'nt affect anything, does anyone else's do this, maybe its common?

[geeves]

Sure its hooked up the right way round? The opposite of that is normal

[BrokenMu]

It's only one wire, is it possible to hook it up the wrong way around?

[geeves]

I would be trying a different sender if you can. That one might be for a different type guage

[BrokenMu]

That's what I'd have thought, but it did work fine until the first oil change (100kms)

[55zed]

I would try a mechanical gauge to compare with the electrical one, are you using a different brand filter?

[geeves]

Can only think of one cause. The bypass in the pump. Talk urgently to your re-conditioner about it. If this is faulty you could be starveing oil at high revs. Engine out to fix

[BrokenMu]

Ok, so the gauge read correctly for about 10 minutes today. Starting to believe that something electrical has failed. I couldn't see the motor lasting more than 1000k's if the oil pump was starving the engine at high revs as I've been running it in hard.