Oil Pressure

[ret_junior]

Hey guys, I need some help or thoughts of what it might be. I have a fully built 03 TT cobra and my stock oil pressure gauge is fluctuating and I changed the sending switch, pig tail, and even bought a aftermarket auto meter gauge and it fluctuates from 0-25 psi and it only hits 25 psi when u give it gas. I'm thinking it's my oil pump but it already has a meling oil pump in it. Plus the motor barely has maybe 10k mile on it.

 

[thomas91169]

it should fluctuate with RPM.

 

[ret_junior]

it drops even at idle. it doesnt fluctuate with the rpm.

 

[cobra2547]

Is 25 lbs of pressure at idle or total even when cruising around? Even then having under 25 at idle sounds low to me especially on cold starts. I just had my oil pump gears break on me so I had no oil pressure. Ended doing an oil analysis to see if anything was badly damaged. Might be a good idea depending on how long it's been going on it's only like 20 bucks to get it done.

 

[ret_junior]

it only reads 25 psi when u give it gas and then it falls back to 0. i bought a brand new meling oil pump with billet gears. hopefully thats my problem! but i dont know!

 

[cobra2547]

I would still do the oil analysis for the little money it costs and the turn around is less than a week. It would suck to put it oil pump and gears in only to find out you have to pull the motor cuz of metal in there. How long did it run with such low to no oil pressure and just wondering what kind of oil you run.

 

[Jimmysidecarr]

it only reads 25 psi when u give it gas and then it falls back to 0. i bought a brand new meling oil pump with billet gears. hopefully thats my problem! but i dont know!

25 PSI max is definitely not right, however "Give it gas" is not how you check for correct oil pressure.

You are going to want approximately 10 pounds of oil pressure per 1,000 RPM when the oil is hot, not just hot but very hot. like as hot as it is ever going to get hot.

Checking oil pressure readings when the oil is cooled off is completely meaningless and will not be helpful diagnosing oil pressure issues.

Which Auto Meter oil pressure gauge are you using? Full sweep? Electric or mechanical.

After getting the oil HOT check your oil pressure a 1,2,4,and 5 thousand RPM. Since all oils thin when hot and thicken when cold, you will have the least amount of oil pressure when it is hot. Therefore that is when it should be tested. If you have a minimum of 50 pounds of HOT oil pressure at 5,000 rpm and it continues to go up as the revs go up, you should be OK.

If you truly only have 25 psi oil pressure ever, you either have a faulty gauge or have or will have serious engine problems.

 

[ret_junior]

hey so i finally had the motor pulled apart and found out i spun a rod barring and took the crank with it!!! so new motor coming soon!!

 

[mustangted06]

ouch

 

[ford_racer]

If you truly only have 25 psi oil pressure ever, you either have a faulty gauge or have or will have serious engine problems.

Jimmy called it.