Ford Mustang Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
99 Posts
Discussion Starter #1
So im having an issue with my oil pressure on a cold start. In the morning when I start my car (engine has been off overnight and is cold) the oil pressure gauge goes to its normal position for about two seconds and then goes to no pressure. I immediately turn off the engine and start it again. Same thing happens. It seems that I have to start it 4 or 5 times until it gets some warmth and then the oil pressure is fine. I haven't had a problem when its warm, only when it is dead cold. Could it be the sending unit? Any thoughts are appreciated!
 

·
Registered
Joined
·
8,704 Posts
Yup probably the sending unit, there's probably a way to bench test it or something that I'm not aware of if you look around (Haynes manual is where I'd start) so you can get a more firm diagnosis. If it were your oil pump then this thread would be titled, "Help! I need a new engine!"

On a side note, you have pulled the dipstick and checked the oil level since this began and it's ok, right? What kind of oil filter are you running, and how old is it? Longshot, but could also be a ****** filter that's plugged up or just not flowing enough.
 

·
Registered
Joined
·
99 Posts
Discussion Starter #3
If it were your oil pump then this thread would be titled, "Help! I need a new engine!"
Yeah that would be true haha

On a side note, you have pulled the dipstick and checked the oil level since this began and it's ok, right? What kind of oil filter are you running, and how old is it? Longshot, but could also be a ****** filter that's plugged up or just not flowing enough.
Oil and filter are fine. I use mobil 1 synthetic and have like 1500 miles left on the oil change.

My guess is the sending unit but im just seeing if anyone else has had this problem or knows for sure what is causing it :)
 

·
Registered
Joined
·
5,431 Posts
relying on the stock dummy lite gauges for accurate readings are fruitless, the factory sending unit will show normal oil pressure with only 5psi:nono:
 

·
Registered
Joined
·
1,068 Posts
Sure sounds like the sending unit. If they are dirt cheap, put one in and see what happens...otherwise have a shop check the pressure with an independent gauge.
 

·
Registered
Joined
·
6,859 Posts
The oil pressure sending unit is a simple on/off switch. It's easy to test by grounding the wire. Once grounded, the dash gauge should read OK.

No ground=no oil pressure.

So anything that keeps the signal from making a good ground will keep the gauge from working.

Suggest starting by checking the wires on the sending unit to see if they are clean and tight. Next ground the sending unit wire and confirm that dash gauge reads "normal". If it does, replace the sending unit.
 

·
Registered
Joined
·
99 Posts
Discussion Starter #7
Thanks for all of the responses guys! My shop is testing it tomorrow. I will give an update when they figure it out!
 

·
Registered
Joined
·
99 Posts
Discussion Starter #8
Yep, turns out it was the sending unit! Thanks for all of the responses guys!
 
1 - 8 of 8 Posts
Top