5.7 Vortec Oil pressure concern.

[NYEngineer]

Murphy switches are called that because they're made by a company called Murphy.

I bet anything that engine has a high pressure pump in it.

I've built countless 350 chevys for marine applications with standard volume and pressure oil pumps. No reason for anything else. You need 10 psi oil pressure for every 1000 engine RPM.

I like V8s to idle at 550-650 in gear.

 

[Serolim]

Originally Posted by clinebarger
Originally Posted by Serolim

Also about the oil mist in the air intake tube, I can't figure out how to upload pics, but I assume u guys knows which tube I'm talking about on the passenger side, not the pcv tube on the drive side. This tube connects from the valve cover to the intake right near the end of the intake up top. Can I put a baffle in there some how? Haven't seen a catch cam made for those trucks that's not a pile of crap. But I assume a good baffle may do it, idk. Just bugs me my others don't have this oil mist. Thanks again guys/girls.


It's called a Fresh Air Tube or a Breather Tube, The OE valve covers ARE baffled. Are your current valve covers aftermarket chrome or something?


Original valve covers, just repainted.

 

[Serolim]

When I bought the truck those years ago, it was a lawyers project, he had passed, and a son of his was selling it for his mother. ~ They has told me it was rebuilt with a new spider spline and all that good stuff. 4 years later it has a coolant leak, lower manifold gasket, I repair it myself with the upgraded steel gaskets from felpro, they had put the regular gaskets on it I had noticed at that point and did all the gaskets from the kit. I couldn't tell if they put the upgraded spider spline, I doubt it.

Anyways the son or mother didn't know much aside from what the father had said befor he passed, so everything has been a mystery unless I open up the engine. Aside from the transmission I had a shop build that up after it had failed.

It has always ran well, and looked good when I had the top open.

Edit ~ just to note, the gear on the distributor looked brand new when I had it off, I had thought maybe it of been worn a bit with a high volume on it. Tho at the time about 50k miles on it.

 

[DoubleWasp]

I would not worry about the oil pressure. Seems pretty typical. Between my trucks and all of the boats we do, I see a LOT of these engines regularly. There is nothing there to complain about. Even when these engines are brand new, some behave differently than others. We buy a ton of L31 crate engines. I've seen some that idle at 50-60 psi hot. Usually a rock solid 40psi hot at a minimum. Some do 25-30 hot.

Where the mist is concerned, I see this a lot too. As these engines get older and blowby takes over, crankcase gases will push a little oil out of the breather hose. Isn't going to hurt anything, but you can use a catch can to reduce a lot of that.

 

[wtd]

The oil pressure on my 98 K1500 with the 5.7L is around the same as your 99 Sub. As far as the high idle, I had an issue on mine where the idle would stay high even after it was warm. I replaced the idle control valve with no results. It turned out to be a bad thermostat. After I replaced that, my idle went back to normal.

 

[jhellwig]

For most of them 25 psi at hot idle is high.

 

[Serolim]

Originally Posted by wtd
The oil pressure on my 98 K1500 with the 5.7L is around the same as your 99 Sub. As far as the high idle, I had an issue on mine where the idle would stay high even after it was warm. I replaced the idle control valve with no results. It turned out to be a bad thermostat. After I replaced that, my idle went back to normal.


I put new everything one item at a time, all BWD or AC Delco

Thermostat Is AC but passed the boiling water test. wires AC, plugs Defni iridium fine points, Cap BWD and rotor, and everything else BWD every sensor u can think of is BWD. I'm anal about it I've had great success with BWD on GM vehicle s.

Thermostat was fine, the rest I replaced as needed with BWD and never had problems again when whatever they used on the rebuild failed one after another over the course of the first 3 years. I noticed today after about a 150 mile trip, that it idled at around 700-800 in drive with my foot on brake at a stop light 800-900ish with AC on.

Side note I also got a baffled catch can for it, I've yet to install it tho. For the oil mist in the intake issue.