Heavier oil

[Smitty1021]

Alright. I just find it odd that I never had this issue before. My oil pressure switch was bad for about a month or two but it's also not my daily. I finally replace it and run a heavier oil and I'm suddenly having issues. Do you think by maybe bumping the idle up a tad, I could spare some time. My goal is to do a motor swap by next summer, but I would like it to last until then.

 

[kennythewelder]

You need to test you OP with a test gauge that screws directly into the hole where you replaced the oil sending unit. A test gauge like I am talking about will give you a true reading of the oil pressure. This will eliminate any doubt in what the pressure really is.

Alright. I just find it odd that I never had this issue before. My oil pressure switch was bad for about a month or two but it's also not my daily. I finally replace it and run a heavier oil and I'm suddenly having issues.

 

[Smitty1021]

Yea I'm gonna try and get my hands on one this week. I'm just trying to rule out all Possible options. Ill write back on here what the True pressure is.

 

[kennythewelder]

There you go, your on the rite track. I'm interested to see what the test gauge tells you. Good luck.

Yea I'm gonna try and get my hands on one this week. I'm just trying to rule out all Possible options. Ill write back on here what the True pressure is.

 

[Smitty1021]

So just got finished with the mechanical gauge on my truck and the results were unfortunately about the same as the gauge on the dash read. 40 psi at cold idle, about 14-15 at hot idle. It held steady around 30psi for a while when it was getting hot and then once I bumped the rpms up, it came back down and leveled off at those low numbers. I do have a pretty bad oil leak from my oil pump, I believe my rear main seal and somewhere else that I haven't been able to locate. Also plenty of pressure once I bump the rpms up even just a little bit.

 

[kennythewelder]

How do you know that your oil pump is leaking?, There is no way to see it, it is inside the oil pan. I'm not trying to be a SA, just asking. The rear main seal should not affect oil pressure. The same is true for any oil leak. The leak would have to be so bad, that you almost couldn't drive the truck, and then it still should not affect oil pressure until the oil level gets low. If it was me and my truck, I would add some STP and see if this helps the oil pressure. It wont hurt anything to do this for 1 oil change cycle. STP is very thick, it kind of looks like honey, if you can't find STP, there are a few other oil additives that do the same thing. All of the ones I am talking about are all thick like honey. I just looked on Autozones web sight and they have STP. How many miles do you have on this engine?

 

[98_k1500]

15 lbs at idle should be fine as long as its coming up with rpm.

 

[kennythewelder]

I kind of agree with 98k_1500. 15 PSI is low, but if it comes up as your RPMs come up, you should be ok. Like I said though, I would add an oil additive. I started to post that you should just keep running the truck, but I wanted to know about the millage first. Worst case you develop a rod knock, and the engine is toast. A replacement crate engine is so cheep these days, that it makes sense to just run the truck until it dies, then do a swap with a crate engine.

15 lbs at idle should be fine as long as its coming up with rpm.

 

[Smitty1021]

Wow I feel dumb, i meant the oil filter adapter, not the pump. I replaced the gasket on there over the winter and its leaking but I had a hell of a time trying to get the bolts back through so I probably pinched the gasket or dislodged it, idk. Anyway the motor has 168,000. My hopes was to have it last until next summer and I was going to look into a ls1 swap. I bumped the idle up temporarily with the adjustment screw on the cruise control cable, just to keep it up when I come to a stop so I feel safer. Do you think it may be a good idea to drill out the plug on the TB to get to the real idle adjuster and turn it up a few hundred rpms?

 

[kennythewelder]

I think that you would do better to drill out the TB adjuster plug to access the idel screw, if you are sure that it is the idel adjusting screw. Its been a while sense I had my TBI , but my Vortec 5.7 L idels at around 900 in nutral or park and around 750 RPM in gear, just as a reference. My truck has 213000 miles, and idels with around 30 PSI when hot. I run Valvoline 10-40 conventional oil. It is hot down here most of the time, and heat does efect oil performance.