Oil pressure gauge pegged out

[87ChevyR10]

Howdy,

Ever since I bought my 87 R10 back in August, the oil pressure gauge has been pegged out. Where should I start looking in order to fix this?

Thanks!

 

[gpmorgan]

Check and make sure the wire(s) are hooked to the sendor unit. It should be on the left(driver side) of the dist. It could be at the oil filter too. No 100% sure on your engine but at one of the locations.

 

[87ChevyR10]

Check and make sure the wire(s) are hooked to the sendor unit. It should be on the left(driver side) of the dist. It could be at the oil filter too. No 100% sure on your engine but at one of the locations.

Ok, thanks!

 

[chengny]

Wherever it's located ( almost surely behind the distributor) it will only have the single male terminal. Ignore the switch that has 3 wires going to it - that one is used to operate the choke heater.

I am pretty sure you mean pegged at the high end - correct? If so be more on the lookout for a short to ground in the sensing leg - that lead is almost always tan in color.

 

[MrMarty51]

Or else the sending unit itself has took a dump and shorted internally to ground.

 

[89Suburban]

Any luck with this?

 

[87ChevyR10]

Any luck with this?

No, haven't had the truck back long enough and I don't have my tools at my apartment. Hoping to get a few things done this coming weekend.

 

[89Suburban]

Sorry about that, been going back trying to see threads that still needed help. Didn't realize it was you going through that stolen square ********.

 

[87ChevyR10]

I do believe the sending unit is grounding out. When I had the dash apart last weekend, I moved the needle to 0 and turned the power on. The needle slowly moved to the right and pegged at 3 o'clock.

Is the unit on the passenger side? Looks metallic silver with what looks like a vacuum line coming off it?

 

[chengny]

Yes, you are right. The oil pressure sender (for dashboard gauge operation) is on the passenger side. The wire connector is a watertight boot - and it does resemble a rubber hose connection.

The other control - the one on the drivers side - is an on/off switch that makes/breaks at about 10 psi. It activates the choke heater as soon as engine oil pressure is established. Also illuminates the choke lamp on the dash. So in a sense, the choke light also functions as a low oil pressure warning.

If the choke light ever comes on while the engine is running - shut down immediately.

 

[87ChevyR10]

Yes, you are right. The oil pressure sender (for dashboard gauge operation) is on the passenger side. The wire connector is a watertight boot - and it does resemble a rubber hose connection.

The other control - the one on the drivers side - is an on/off switch that makes/breaks at about 10 psi. It activates the choke heater as soon as engine oil pressure is established. Also illuminates the choke lamp on the dash. So in a sense, the choke light also functions as a low oil pressure warning.

If the choke light ever comes on while the engine is running - shut down immediately.

Thanks! I'd like to replace that pronto; however, it's too freakin' cold out to do anything!

 

[89Suburban]

Aren't '87's fuel injected?

 

[87ChevyR10]

Aren't '87's fuel injected?

Yeah, why do you ask?

 

[89Suburban]

I just got confused about the choke light discussion.


Sent from my iPhone using Tapatalk

 

[chengny]

Hah, he's right! I have a bad habit of skimming over the year of the truck.

While the info on the oil pressure sender for the gauge is valid - you can disregard the description of the oil pressure switch and also the choke light as a low oil pressure indication. You wouldn't even have a choke at all.