I am trying to figure this out, so tomorrow I will throw a mechanical gauge on it. My issue is this. I start the truck after sitting for a while and sometimes the oil pressure gauge doesn't move. When I initially turn the key to power accessories, I can see it gets power, but when I turn the ignition the "check gages" light comes on and no oil pressure is shown. If I turn the truck off and start it up again, or maybe twice, I get a pressure reading and have absolutely no problems after that. Pressure holds totally fine at idle and while driving.

Changed out the oil pressure sensor tonight, going to change the oil and filter tomorrow and put a mechanical gauge on it. Which is my second issue, I would like to verify that indeed the mechanical gauge is going show pressure while the cluster shows zero. Where would I be able to hook up to verify the clusters reading? If I hook up to the sender spot i lose the output to the cluster.

No weird noises. Oil is clean and at the proper level. I did just change the heater core, wondering if I need to pull the gauge cluster out again and mess with the connectors. Obviously I am hoping it is a connection or gauge issue and not the engine.

The only thing that could indicate this is that that the pump is losing prime, which I find hard to imagine.

 

If I understand this correctly, when you first start the truck the oil pressure gauge reads 0 and you are getting the check oil pressure light?

I wasn't clear on whether or not this stays like this or if its just for a second.

If its just for a second then I'm pretty sure that's normal. Mine does the same thing which makes sense that it will take a second to build oil pressure.

If you're saying it reads 0 while idling then Id definitely throw a mechanical gauge on it and check your connections.

 

Hey there,

It is not just for a second. It will keep doing it until I shut the truck off and restart it.

 

Hmmm, do the simple things and check the connections on the oil pressure sending unit, unhook your battery. If that fails but a mechanical gauge on it and check it. If that proves to be good then I would check your dash connections since you said you had the dash apart doing your heater core.

Id also wait for a few more suggestions from other members.

When the truck shows oil pressure, does it ever drop while driving? If not then its likely holding pressure and just an electrical issuem

 

My problem with the mechanical gauge is that I don't think I can run the mechanical gauge and keep the oil pressure sending unit in place while I do it. I'd say 9 out of 10 ten times I don't have any problems. So ultimately to verify that it is electrical, I would need to have the mechanical gauge dispute what I am reading on the cluster.

Truck has never dropped pressure while driving. I tend to agree with you, it is most likely electrical, but my heart still stops everytime I see that check gages light.

I found one thread on another forum with an identical problem, and it ended up being the pressure switch or sending unit. I changed mine yesterday, and had the same problem later on. I am starting to wonder if the new unit is bad too. I have had that a lot more in recent years, new parts being defective. Foreign made garbage.

 

That last comment is too true. My father just went through 3 alternators till he got one that wasn't faulty. Went with a different brand the most recent time it failed on him.

It could also be the wiring and not the part itself. Wouldn't hurt to give the wires a quick check.

Couple months back I spun a crank bearing so I would have zero oil pressure as the oil warmed up and thinned out. My own stupidity thinking my dak could drive through a swap that some boats wouldn't attempt

Good luck, let us know your findings.

 

That's a good question, where to connect a mechanical gauge. Especially with the sender where it is. Big block Chevy's have a port behind the odd head and one above the oil filter on a stock block. No idea where our trucks have a port.

 

Just put a T in the factory location an connect both of them.

 

Just make sure to use thread tape or thread sealer, and I doubt the threads will stop where you'll need the fitting to point.

 

I would say that's the number one problem crap new parts some stuff is just garbage not worth a penny.

Rebuilt has never been a good choice like alternators I would never buy a rebuilt alternator a junkyard one yes but never rebuilt not worth it, starters the same never buy rebuilt.

I came to the conclusion years ago rebuilt parts will last you 2 or 3 years at best

I know some stuff rebuilt is the only choice you have