transxtreme

On startup the gauge reads 60 plus psi. At about 120 degrees it dips down until i get on it then it jumps back over 60. After 180 it reads so low it dips into the red zone and goes up little when i get on it. Never seen an oil pump do this before. Any ideas? Thanks in advance.

Stephen 87 IROC

Could be almost anything but I would say an engine teardown will soon be needed. I had a similar problem late in the race season. Good oil pressure when cold but dropped dramatically once the engine started getting some heat in it.

My problem was a spun main bearing.

Pull your oil filter off and cut it open. Use a hammer and a sharp putty knife so you don't get cuttings in the filter. Cut about an inch from the base. Take a section out of the paper pleats and squish it in a vice to get the oil out of it. Open it up to see if there's any metal buried inside the pleats. That is if it isn't obvious after cutting open the filter.

teke184

put a mechanical guage on the car and watch it, there could just be a problem with the stock guage or sending unit.

i know i was worried about fluxuating oil pressure with my old iroc, put a guage on it and found that it had more then the needed pressure at all rpms.

mako350Z28

My car does the same exact thing. It's probably just your sending unit. That's what my problem is.

teke184

if i remember correctly, factory spec is like 18psi of oil pressure at 2000 rpms...so as long as yours doesn't drop below that you should be fine.

i know mine use to read MUCH higher than that all the time

Stephen 87 IROC

Mine was within specs but I still had mechanical problems.

transxtreme

Im gonna install an aftermarket mechanical. Any suggestions. I have a sunpro triple pod layin in the package. Oil, temp, volts. That fine or should i invest in autometer? And also it dips down into the red zone sometimes almost too zero. I wouldnt rule out that i spun a bearing. Stock shortblock thats been taken to the rev limiter many times.

Stephen 87 IROC

Don't run the plactic line into the car or you won't be allowed on track. Oil lines inside the car must be steel braided or hard line (copper)

aklim

I had another car that ran the same way. Changed oil sender and all is well. Not saying that is your problem but try it before you tear the engine apart. New sender is under $20, I would think and easy to get to also.

transxtreme

Alright thanks for all the help. What about those sunpro gauges? Im selling the car soon so i dont want to invest unless i should.

slimdawson

I wouldn't worry about it if you were going to sell it.

Factory gages aren't known to be accurate so it might not be too low. Mine reads past 60 when cold. When it warms, it reads around 30-40 at idle and goes back up when revved. Has over 70k miles on it and haven't had any problems. I am sure one would have shown up by now if the pressure was too low.

aklim

Change the sender simply because someone might be **** about it and try to lowball you. Only a few bucks