lacycw

Today after I went autocrossing, I noticed my oil pressure was a lot lower than usual. It normally runs about 20 at idle and 40-45 cruising on the highway. When I was driving back, it was barely registering 5-10 when cruising in 5th, but when i shifted into 4th (3700 rpm), the pressure jumped up to 45-50. Could the oil pressure guage/sensor be going bad or could it be the oil pump. Do either of these have a history of failing often. The car had plenty of oil in it and was not leaking at all after I let it sit for an hour or so. I also don't drive my car very far normally and it may have a bit hotter than usual, although the heat guage was where it always was. I run Castrol GTX 20W-50 and I've got about 100K on my engine. It was about 90 degrees Fahrenheit outside. Let me know what you think.

-Coop-

Wankel7

The sending unit is know to problematic at the least. The pressure you are describing is low. However, you are quoting figures from the stock gauge.

If you are truely worried about it get an after market gauge. OR a mechanical gauge and thread it into the hole where the sending unit is.

James

Icemark

Your normal readings are 10lbs low... You current readings sound very low- like don't drive low.

You need to check if it is really low or a malfunctioning sender ASAP.

Have you replaced or shimmed the ecentric shaft thermo bypass valve yet? That is a reliability mod.

And what year motor?

lacycw

This is a 90 motor in a GTU. I drove my car today and everything was back to normal. I haven't replaced or shimmed the bypass valve yet.

-Coop-

Angel Guard Racing Team

Since you went auto crossing, your oil temperature might have raised above normal driving temperature, therefore the oil might have lost viscosity due to thermal breakdown.

If everything is back to normal after it cooled down then that could have been it. I live in a hot tropical island, so I use 20W50 in my cars... Synthetic Oil is great also.