Low Oil Pressure on Hot Idle

[bvlmv]

Hello to all.

I've been getting a low oil pressure alarm on my dash after the engine is hot and idle (0- 10 PSI). So far I've changed the sendor, switch, oil grade (20w50) and finally the dash so I'm thinking it's something internal. When the alarm goes off the engine feels fine and doesn't hesitate at all. The oil pressure returns to normal (40-60 PSI) when I start moving again.

Anybody experience this on their VP engine?

BTW I have a 99 5.0Gi PWTR


Thanks in advance!

 

[Scott Danforth]

Re: Low Oil Pressure on Hot Idle

have you put a mechanical gauge in the oil port and actually measured it? you could have low oil pressure.

how many hours on the motor?

 

[muc]

Re: Low Oil Pressure on Hot Idle

Other things to check might be low idle speed and install a quality oil filter.

 

[bvlmv]

Re: Low Oil Pressure on Hot Idle

have you put a mechanical gauge in the oil port and actually measured it? you could have low oil pressure.

I'm not able to replicate the issue while one muffs so I'll put one on next time I go out.

how many hours on the motor?

Unfor the boat didn't come with a meter so I'm not 100% sure.

 

[bvlmv]

Re: Low Oil Pressure on Hot Idle

Other things to check might be low idle speed and install a quality oil filter.

I use the VP brand but it's worth a try. What brand do you use?

 

[muc]

Re: Low Oil Pressure on Hot Idle

I use Volvo, MerCruiser or Wix

 

[gm280]

Re: Low Oil Pressure on Hot Idle

Not knowing the true oil pressure you have, maybe your oil pump is wearing out. However, it is said that 10lbs per 1000RPMs is acceptable for oil pressure. The fact that your stated that the pressure rises once you apply more gas and the engine rives up is quite common with older engines. All the bearing surfaces do wear and increase their clearances and that tends to lower the actual pressure. But you have to have enough flow or there would be temperatures raising as well... I would much rather have lower pressures then high pressure with lower flow rates...

 

[dypcdiver]

Re: Low Oil Pressure on Hot Idle

I also have a 99 5.0Gi PWTR that I have had from new (600hrs), I use VP filters and Mobil S semi synthetic 10-40w. When warmed up she has 5 to 10psi at tick over (600rpm) and 35-40psi at 3000rpm. It has always been the same.
I would be inclined to test it with a mechanical gauge, just to put your mind at rest.

 

[bvlmv]

Re: Low Oil Pressure on Hot Idle

Not knowing the true oil pressure you have, maybe your oil pump is wearing out. However, it is said that 10lbs per 1000RPMs is acceptable for oil pressure. The fact that your stated that the pressure rises once you apply more gas and the engine rives up is quite common with older engines. All the bearing surfaces do wear and increase their clearances and that tends to lower the actual pressure. But you have to have enough flow or there would be temperatures raising as well... I would much rather have lower pressures then high pressure with lower flow rates...

Temp stays between 165-175 max.

 

[bvlmv]

Re: Low Oil Pressure on Hot Idle

Will do.
Do you know of a "T" type of connecter so I can have the sender and mechanical gauge connected at the same time?

 

[Bondo]

Re: Low Oil Pressure on Hot Idle

Will do.
Do you know of a "T" type of connecter so I can have the sender and mechanical gauge connected at the same time?

Ayuh,... just use an 1/8" pipe Tee,....