I recently bought a Camaro RS it has a carbed 305 in it. It has an Holly Dominator intake anyway my oil pressure is all over the place. When I start it in the morning the oil pressure will be up around 20 PSI when the car warms up to around 180 and I come to a stop the pressure will drop below 20 psi sometimes around 0. The oil is full I have no idea why there is this much difference. I was wondering if someone could give me some ideas of what this could be.

 

Could be a bad sending unit, wrong weight of oil, the filter you are using or worn bearings in the engine. Test it with a mechanical guage to see what it is reading.

 

The gauge I have is a mechanical gauge. 10w40 is what was ran at least that is what I was told

 

was it doing that when you purchased the vehicle? caveat emptor

I know that sounds callous but people sell vehicles for a reason.

If you don't know how to check the pressure, bring it to a local shop, pay the 1 hour labor and have them tell you and also quickly go over the vehicle.

You need to know what you have and are facing with respect to needed repairs. You may get angry at what you discover but knowledge and information are a good thing.

The vehicle is 20 years old.

 

Not that I noticed I drove it around for awhile and never really noticed the oil pressure drop at all. Drove it all the way home over 100 miles and did not really notice it either but that does not mean anything maybe I just did not notice for some reason.



Trust me I know this I have been taken for a ride several times only to get a car and find out it needs a grand in repairs.

I will take it to my shop and let them know what I am seeing and let them check it out. Did not know if I could get some answers hear first of sme possible things to check.

 

One thing I forgot to say is that when I am actually driving the car the oil pressure is fine it barely moves

 

20 is a bit low when driving. But, it's only conjecture on the part of all of us. Is the issue the sending unit, the gauge or do you have an oil pump or lower end problem. There is insufficient information to determine this.

 

Thanks I will take it in to the shop got to have some money saved up first. It drops to 20 when I stop when I am rolling down the highway it is around 40.

What I was going to do is change the oil and see if that does anything and then I was going to put it in the shop if it stayed the same. I personally like to use the Rotell 15w40 so I will do that and then get it in the shop and see if they can tell me what is going on. Thanks for all of the help.

 

20 psi on a cold engine is waaaaay too low, since it only goes down from there as the engine warms up. And it absolutely can't be a bad sending unit, you don't have one with a mechanical gauge. Mechanical gauges tell it like it is, unless the gauge is faulty (which isn't beyond the realm of possibility). I'd question the accuracy of the gauge, but if it is correct, then you have some serious (possibly detrimental) engine wear.

 

thats a contradiction to your first statement. 20 to 40 lbs of oil pressure is normal. 0 to 20 is not.