GREMLIN IN MY 03 4.8

[99Sierra2500]

i just realized something that i didn't think was even involved somehow.
my oil pressure gauge is pegged out and has been for a long time
maybe as long as this has been going on
could the oil pressure sensor send bad info to the ecm causing it to shutoff fuel or try to save the engine ?
maybe ,,could be,, ok i know i may be reaching.

Could be. It is good to check everything (doesn't hurt). Truck's been around the block. Gut feeling is that rough idle, and stalling when hot is a vacuum leak, esp if not throwing a code. Difficult to say though, I just don't know. MAP reading or a vacuum gauge might say something in that direction. Maybe the oil sensor is doing a shutoff.

 

[stutaeng]

No, the sender won't cause your engine to die.
When I was diagnosing low oil pressure on 4.3, I hooked up a mechanical pressure guage, and somehow forgot about it. I drove like a week or two before I remembered. The pressure sender was obviously disconnected during that time.

Check the passenger side valve cover that hooks up to the throttle body, and the PCV hose. Those become brittle with age and crack. The PCV hose likes to crack right at the valve cover connection.

 

[the old man]

No, the sender won't cause your engine to die.
When I was diagnosing low oil pressure on 4.3, I hooked up a mechanical pressure guage, and somehow forgot about it. I drove like a week or two before I remembered. The pressure sender was obviously disconnected during that time.

Check the passenger side valve cover that hooks up to the throttle body, and the PCV hose. Those become brittle with age and crack. The PCV hose likes to crack right at the valve cover connection.

ok i will ,,,,,another thing i thought about is the EGR valve... but wouldn't that throw a code.. ?

 

[stutaeng]

ok i will ,,,,,another thing i thought about is the EGR valve... but wouldn't that throw a code.. ?

EGR may cause a surging if get stuck open, so that's something to look at. But yeah, it should throw a code.

You can remove the valve and inspect it. I've read sometimes they can get a piece of carbon deposit hanging it open. It's been since I've taken one apart?

 

[the old man]

well i ordered a new ac delco gas cap,, ac delco fuel filter and ac delco oil pressure sensor and
we'll see what happens after i get those installed.. and i will clean the TB and check for vacuum leaks.

 

[ORVietVet]

well i ordered a new ac delco gas cap,, ac delco fuel filter and ac delco oil pressure sensor and
we'll see what happens after i get those installed.. and i will clean the TB and check for vacuum leaks.

You don't have to get an AC Delco throttle body seal. Fel Pro is fine.

 

[the old man]

You don't have to get an AC Delco throttle body seal. Fel Pro is fine.

i cleaned it this morning on the truck. i just turn the key on and prop the gas peddle to the floor
and scrubbed the fire out of it with a toothbrush and rags.... it was pretty nasty... it seem to idle a little better.. i have not drove it yet...

 

[ORVietVet]

i cleaned it this morning on the truck. i just turn the key on and prop the gas peddle to the floor
and scrubbed the fire out of it with a toothbrush and rags.... it was pretty nasty... it seem to idle a little better.. i have not drove it yet...

You got it clean but it is not clean/clean unless it is removed.

 

[the old man]

yeah yeah i know but me worry bout mo problems if i take off and unhook the wires ..
i did put my new fancy obd2 reader on it yesterday and checked live data but i didn't
know what i was looking for ,, 24 different things to read..... gotta do some studying.

P S mine was much dirtier then that one

 

[the old man]

this morning i check it in the freeze frame mode to see if any incidents showed up ,,nothing on it came up.
there were no codes or pending or stored codes either.

i am going to drive it with the scanner on it in live data and see what happens next