spiking VERY high oil pressure

[NickVyse]

This is a weird one. Rebuilt my engine a year ago, including a new oil pump. Installed an oil pressure and temp gauge at the same time. All well for the last 12 months/5,000kms.

 

In the last week, when cold, the pressure has gone from it's normal high of 7 bar/100psi with a few revs, to suddenly and rapidly pegging the gauge. Coming straight off the throttle sees it come back to normal.

 

This then repeats a few times, with my driving as gently as I can, coming straight off the throttle everytime it happens, and then stops after a few kms. It's done this 3-4 times now.

 

First time it coincided with the need for an oil change anyway, so a new old style insert filter went in (this is my '65 NK) and the same VR1 20-50 was swapped. Made no difference.

 

I can only imagine a sticking pressure relief valve, but seems odd in a 1 year old pump in a one year old engine. Unless the pressure sender is going haywire (VDO).

 

What's especially weird is that the engine can be operating at a constant 3k, for example, same light throttle, pressure pegging at 7 bar and THEN it suddenly spikes. To me this wouldn't indicate the relief valve sticking, as it's already doing it's job and would have to physically close to create what I'm seeing. I think!

 

Happened last night when cold at around 5 degrees/41f, but not today when the ambient temperature is a warmer 10 degrees/50f.

 

Anyone else experienced something similar?

 

Cheers, Nick

Edited May 4, 2019 by NickVyse
more info

[02Pilot]

It's almost certainly electrical. Check your wiring first, as that's the most likely cause. Also be sure the sender is grounding properly.

 

[NickVyse]

2 hours ago, Andrej said:

It's almost certainly electrical. Check your wiring first, as that's the most likely cause. Also be sure the sender is grounding properly.

 

 

in retrospect that was bloody obvious! The spade connector ontop of the sensor wasn't as tight as it should be - quick pinch with some pliers and reckon that's sorted.

 

Cold temperature and coming off the throttle was throwing my logic (or lack of). Obviously coming off the throttle rocked the engine the other way and remade the connection.

 

It's good to be reminded you're still dumb even when you pass middle age and think you're smart.

Edited May 4, 2019 by NickVyse

[02Pilot]

It's always nice to resolve a problem, especially an electrical one, without too much of a fight.

[EPK]

Trust me, I've been there . I chased a lack of spark until I was nearly insane. I had an incorrect wire connection. I felt like a total fool and discovered it based on the color of the wire. It suddenly hit me that the wire was the wrong color.

I was able to rebuild/refresh a motor, install a 5 speed, etc but couldn't do something so basic as switch distributors. Stuff happens.

I'm glad you figured it out.

Sent from my SM-G950U using Tapatalk