Td42 Oil Pressure Fluctuations at low RPM

[Bigbird91]

Hey Guys and Girls,

Been a hot minute between having an issue with the old girl that I couldn't get myself out of trouble.
The trusty old Td42 has started losing oil pressure at idle and upto about 1200rpm. This is after the car has been running for about 10min. On first start up on the cold engine everything is as normal, this makes me think the autometer gauge and sender I have installed is fine. Once you get about 1200rpm oil pressure comes back to normal until it's been running for about an hour then the revs need to be kept about 1600rpm to keep oil pressure up. The oil pump was replaced when the engine was rebuilt approximately 15,000km ago. Have only used Penrite 15w50 diesel oil and ryco filters and I changed both of them less than 1000km ago and the oil still looks fine on the dip stick.

Has anyone got any idea what could possibly be going on or where to even start looking for an issue?

Cheers in advanced

[mudnut]

Could be diluted by diesel. Also recheck the connectors. sometimes as the circuit is heated, by current flow or the heat of the engine, it can cause a high reistance.

I was towing a trailer on a big trip last week and oil pressure started dropping off. The first thing I checked was to push the oil pressure sensor connector on tighter. The pressure reading was good and it had no further trouble.

[Bigbird91]

Cheers Mudnut,

You've hit the nail on the head. Put a drop of oil on the paper this morning and after about 10min on the bench there was a decent ring of diesel forming around the oil drop. Let the fun begin on the quest to solve the mystery of how it's getting in there.