Oil pressure question

[slowfrc]

I went to look at a 98 GTS last night that I was very happy with. I meticulously looked over the car and drove it for a while to make sure everything worked as it should. Everything seemed fine and by the end of the night I had given the owner of the car a deposit and am almost ready to go on the car. The only thing that worries me, or maybe that I'm unclear about, is the oil pressure. Once the car was up to operating temp (i forgot to check before that) it ran at high 30s at idle. I revved the car to about 4k and held it there to see how the pressure would react and it wouldn't climb any higher than low 40s (maybe 43/44 psi).

I have a c5 corvette now and the pressure rises much higher under load, as does every other vehicle that I've ever owned that had a pressure gauge. I did a search and people were saying their cars ran anywhere from around 40psi all of the time to some as high as 70psi. Admittedly I don't know these motors as well as I should. Would the pressure bother you guys or is this normal? Other than this I am in love with the car can't wait to pick it up.

 

[rukcus]

There are many factors that can effect oil pressure in a engine. From the ambient temperature to the viscosity of the oil itself. Most factory oil pressure warning lights will illuminate when below 5 psi. Having your oil pressure hovering around 40 psi when at operating temperature sounds good to me. Source: I am a professional engine rebuilder.

 

[klamathpro]

Did it go any higher than 40 while driving? Both my Vipers get to 60psi under load. Revving without a load may not quite get it all the way up to full pressure. Plus the gauge lags a bit. Idling as low as 20psi is normal. Also, ask him what oil he uses. You didn't say where you are located. Higher temperature environments mixed with low viscosity oil will yeild lower pressures. If it was hot and he uses 5w30, that may be the problem. 10w30 was recommended from the factory, 5w30 for colder temps.

 

[Dom426h]

Prob not a concern. My oil pressure is never that low but ive seen alot of variance between motors reading through the forums. Seems as though our guage and/or sending unit is not so accurate. From what i remember mine stays around 45-70psi. I run 40wt oil with the mopar "viper" filter so that might differ in pressure from someone running 30wt and a diff filter.

this is searchable:
search keywords, "pressure, normal, idle" in the RT/10 and GTS Discussions and you'll come up with several results including:
http://forums.viperclub.org/threads/580899-Oil-Pressure-need-help
http://forums.viperclub.org/threads/579783-Oil-pressure-reading
http://forums.viperclub.org/threads/570865-oil-pressure-question

 

[DrumrBoy]

I notice a difference between idle-load difference between 0W30 and 15W50 in the same car. They both hang around 40 most of the time but the 15W50 goes to 50 psi or so under load where the thinner oil goes maybe to 42 or something just slightly higher than normal.

 

[Allan]

I agree with the rukcus dude, and I am also a professional engine rebuilder. I don't think there is a problem with that car. -loud knocking from the engine with very low or no oil pressure would be a big concern.