Oil pressure & Temp - what to expect

Sorry if this is a numptie question. Running a VVC engine with whatever oil Steve Williams put in - presumably the recopmmended one. I had SPA dual oil pressure and temp gauges installed by Steve Williams last week. Oil temp on a sump plug adapter and pressure off the oil filter housing.

Pressures are around 60 psi at tickover when the oil is cold, dropping to 30 odd with oil temp ~80+C. After a heavy track session when the oil got to 109C, the pressure was 22-25psi.

Under throttle pressures around 70 psi with hot oil.
Does this sound about right for a VVC engine with no modes?

2nd question is that during the track session, the oil pressure gauge suddenly started to give really wacko readings and only sorted itself out on the journey home. The airfield was really bumpy and I wondered if it wasn’t a wiring or wire connection problem. The temp sensor which I believe shares the same earth was unaffected. Any ideas where to start with fault finding?

Cheers again.
Andrew

Oil pressure sounds a bit low to me. Mine (VHPD) is about 45psi at 80oC tickover (5w40 I think).

Where/how are your sensors mounted?

Ian

I would say it’s kind of low too, may be the oil pump gears need replacing.

And I would tend to agree, electric wiring could be the cause of the weird reading. Have you tried swapping them over to see if the failuire follows one of the wires or satys with the gauge?

The sensors are mounted as follows:

  1. Temp sensor on a sump plug adapter
  2. Pressure sensor on the oil filter housing.

The VVC does not have the same oil pump setup as the VHPD iirc. I better check with steve williams what oil he put in. Level is fine, but I did worry the pressures seemed low. The low pressures are with the oil >100C and the normal warning light does not come on at all.

Cheers
Andrew

Pressures are perfectly fine.

Oil pump is the same in all K series engines AFAIK.

If you run a laminova oil cooler (the size that EliseParts sell) you may notice the pressure being lower. When I removed mine I picked up about 5psi at tickover and slightly more at higher rpm.

I think the S2 VVC engine has a small laminova style oil cooler fitted as standard. If you retain this and fit an additional oil cooler you may get a drop in oil pressure.

The sump plug sender install is not ideal sionce the sump masks the sender and only the tip gets exposed to oil. I’ve fited mine into the side of the sump, above where the sump plug fits. My sender is fully exposed to oil and now reads higher…

For refence I use the SPA gauges too (nice bits of kit)

The spurious readings are most likely a bad connection somewhere - probably not the earh since the both senders share the same earth - the block.

Thanks for the detailed info - really helpful. The onerous task is now going to be finding the loose connection - I will take the undertray off on the weekend. I will also have a look at what I can do about resiting the sump plug adapter for temp.

Cheers
Andrew