oil pressure guage spiking

[dustinbrown]

so the oil pressure guage seems to read as should untill i get up to 65mph then it pretty muvh just spikes. has anyone else came accross this issue? it is on a 93 with the detroit 500hp

[patticake]

Sounds like the sender is malfunctioning. I may be wrong, but there are only the two items in this.
Also, can you duplicate the malfunction by revving the engine in neutral? If so, add a mechanical gauge in the engine compartment and watch it.

[Itchintogo]

I would check your connections to the sender from the gauge to the engine. Could be the sender but...It sounds like something is corroded or loose causing a voltage gain/loss that makes your gauge spike. At engine idle disconnect the sender for a moment and see what that does to your gauge. If it spikes then you are on the right track if it falls to zero look for a short. Look for a worn place in the wire circuit perhaps where the wind can get at it. The fact that it works as it should below 65 MPH might suggest the sender is ok.

[Itchintogo]

Something else just dawned on me. I am not sure but most systems have a oil pressure bypass valve. In some cases this is in the oil filer. It is there to stop over pressure scenarios upon cold start up. If the wiring or sender does not fix it maybe changing the oil filter might? Believe me I am grasping here but I know I have heard of filter related problems in the past. If anyone can contribute please jump in.

[Gregg]

My 94 had the same problem, it was the sender. First sender worked for 500 miles and failed, second sender still going. I added silver leaf, which I wouldn't drive without now.