Questions and Answers

Nissan Oil Pressure Problem Q. Vehicle: 1990 Nissan pick up truck; model KA24E; 4 cylinder; 5 speeds; 150,000 miles; no A/C or power steering; electronic fuel injection; 2WD. Vehicle repair history: Few month ago, the timing chain was making the rattling noises due to a broken chain guide. I removed the old chain and replaced it with a new timing chain kit.

Later on I discovered the coolant was been leaking into the engine oil. Last week, I removed the timing cover and reapplied the silicone seal. I replaced the oil filter and poured in new oil. The timing and idle rpm was good and no external leak, but the oil pressure warning light appeared on the control panel. I test drove the car few times and oil pressure still stay on.

Questions:

1. Do you think the oil pressure light came on due to my remove/install of the timing chain, oil pump, oil pan, and distributor?
2. I did not fill the oil pump fully with oil before putting it back. Do you think this could cause the oil pressure light to come on?
3. I visually inspect the oil pressure sensor and did not see any leak around the base. With the engine off, I measure the resistance of the oil pressure sensor and receive a values of 35 ohms (is this value any good?).
4. Can you show me how the fix this oil pressure light problem?

Thanks, for all the help and I am looking to hear from you soon.

A. The timing chain guides were known for breaking in that engine and Nissan came out with a technical bulletin and improved parts for it. I know I have replaced quite a few of them myself.

There are only two possibilities here, the Oil Pressure switch is bad or there is no oil pressure. Since the light was not on before you did the job, I think it's safe to assume that the pump is not pumping.

The only thing you had to remove to get the oil pan off was the oil pickup tube. There is a gasket that goes between the pickup and the block that must be installed. If not, it will suck air instead if oil. Also make sure the screen is clean so the oil can be picked up.

That pump is self priming so it should pick up the oil without priming. At this point the only thing you can do is drop the pan and make sure the pick up is installed correctly and if it is, you will need to prime the pump.