2000 5.3 oil pressure warning

Today I started my 2000 Suburban on the coldest morning ever, -14 degrees actual temp. I went inside to let it warm up and about 15 min later I went out to go to work and the check oil pressure light was on and oil pressure read 0. Is this due to extreme cold and thick oil ? Or did something break on start up. I am going to wait until temps are up before I try it again as it was running awful. I am fearing that 15 min warm up may have hurt her.

Today I started my 2000 Suburban on the coldest morning ever, -14 degrees actual temp. I went inside to let it warm up and about 15 min later I went out to go to work and the check oil pressure light was on and oil pressure read 0. Is this due to extreme cold and thick oil ? Or did something break on start up. I am going to wait until temps are up before I try it again as it was running awful. I am fearing that 15 min warm up may have hurt her.
I would go to Advance Auto or Auto Zone and get a loaner manual gage to check the pressure. What weight oil are you using my 2000 Silverado has around 40 psi when started and comes up as I drive. It made a lot of noise but this is normal for this vehicle about 29 degrees where I live. I used to live in Ohio and I remember -18 degrees and I had oil pressure in my vehicles. You may have a bad sending unit.

I hope its just the sending unit. I thought it was strange that I have had good oil pressure up until last night when it sat outside at -14 and wind chill of -48. I have never had any oil leaks and run 5/20 in it, but at 211,000 miles the cold would probably find the weak spots. I have heard of these pumps having a stuck pressure valve inside them also, that reroutes excess oil away from the out flow when overpressurized and back through the system. I am hoping the expansion of the metal from the cold is holding it open and it will be ok when temps reach 34 by friday. I am worried about the engine now that it ran that way for a good 15 min. My son drove it to work and back the night before and im not sure if it was this way then or not, he doesn't pay much attention to those details.

I hope its just the sending unit. I thought it was strange that I have had good oil pressure up until last night when it sat outside at -14 and wind chill of -48. I have never had any oil leaks and run 5/20 in it, but at 211,000 miles the cold would probably find the weak spots. I have heard of these pumps having a stuck pressure valve inside them also, that reroutes excess oil away from the out flow when overpressurized and back through the system. I am hoping the expansion of the metal from the cold is holding it open and it will be ok when temps reach 34 by friday. I am worried about the engine now that it ran that way for a good 15 min. My son drove it to work and back the night before and im not sure if it was this way then or not, he doesn't pay much attention to those details.
With that light of oil it should have reached full pressure in 15 min. Did the oil pressure come up and the light go out before going in the house to warm up hopefully?

I didnt notice the warning until I backed out of the driveway that day. Barely made it back up drive, low power and wouldn't stay fired up.

I didnt notice the warning until I backed out of the driveway that day. Barely made it back up drive, low power and wouldn't stay fired up.
This doesn't sound good wait until its warmer and recheck. A rebuilt short block and valve job, long block or a used motor is probably worst case. Running say 10 min. with no oil has spun a few bearings.

I am praying that friday when its above freezing it will come alive ! Never fails having to work on a vehicle in the dead of winter.

I am praying that friday when its above freezing it will come alive ! Never fails having to work on a vehicle in the dead of winter.

the oil to use is 5-30wt. I recommend synthetic in these engines. if the oil pressure was zero the lifters would be very loud.

did you check the oil level ?

if you take the oil fill off see if you smell coolant. see if coolant low could be the block cracked coolant in the oil . bottom of pan could be frozen with water.

Oil level was good, no coolant in oil. Was running and driving great before the deep freeze settled in.

Oil level was good, no coolant in oil. Was running and driving great before the deep freeze settled in.

with no oil pressure the engine will make a lot of rapping.

with my 5.3L 2000 the oil is synthetic 5-30wt . pressure when cold 65 psi max. at idle when hot 40 psi min. at 2000 rpm 48 psi. 150,000 miles . orig owner.

Synthetic smenthetic, 5w is 5w. "Engineerred oil" is theoeretically better, but not worth the extra penny IMO, more important to change it like you should. Oil tech has came a long way in the last decade even... Like said should've been at pressure by then. That and not wanting to run doesn't sound good. With lack of oil 5 minutes can lock em up. Stick a manual gauge in it to check it, the dash gauge is a glorified "idiot light" honestly. Was it hammering too?

I have been letting it sit since monday since it has been in the negatives all week. I did try to see if it would turn over around 630 pm today and wouldnt start due to the battery being low after sitting out all week. It did turn over though. Supposed to be 34 tomorrow so I will put the jumper box on it and see what happens. I dont have much hope. Might not turn over easily because all the friction from spun bearings, warped crank and shrapnel in the block. When it last ran it was pretty rough. All from warming up my vehicle. Another lesson learned !!!!

I have been letting it sit since monday since it has been in the negatives all week. I did try to see if it would turn over around 630 pm today and wouldnt start due to the battery being low after sitting out all week. It did turn over though. Supposed to be 34 tomorrow so I will put the jumper box on it and see what happens. I dont have much hope. Might not turn over easily because all the friction from spun bearings, warped crank and shrapnel in the block. When it last ran it was pretty rough. All from warming up my vehicle. Another lesson learned !!!!
From past experience the oil pump strainers were plugged and oil pressure wasn't zero but maybe 5 to 10 psi at idle. if doing the job yourself maybe a short block and valve job. You could change bearings,clean strainer, install a new oil pump,and relief valve. But your taking a chance it won't work. A garage wouldn't do this because if it doesn't work they very likely would have an irate customer if it doesn't work.
Any its not cheap.

Fired her up oil pressure came back. But TICK, TICK, TICK,TICK............NOT GOOD

Fired her up oil pressure came back. But TICK, TICK, TICK,TICK............NOT GOOD

with the engine cold remove the oil drain plug for a second to see if water comes out or sludge.

if the oil looks clean then add 6 oz of marvel mystery oil to the crankcase oil. see if the lifters quiet down with idling for 15 min and you have oil pressure.

Now I am confused. There was coolant in reservoir on thursday when I checked it. Today it is low, very low. At -14 I dont think dex would freeze would it ? If it did then I probably do have coolant in the oil. Either the head gasket blew on startup that morning, or the block cracked. Checking oil in the morning. I think that after all this on this 211,000 mile motor the old girl might be done. Too many issues for an engine rebuild.

Now I am confused. There was coolant in reservoir on thursday when I checked it. Today it is low, very low. At -14 I dont think dex would freeze would it ? If it did then I probably do have coolant in the oil. Either the head gasket blew on startup that morning, or the block cracked. Checking oil in the morning. I think that after all this on this 211,000 mile motor the old girl might be done. Too many issues for an engine rebuild.
Where you live unless you have a heated garage even a head gasket is out of your capability until spring. On your anti freeze it depends on the concentration.

Now I am confused. There was coolant in reservoir on thursday when I checked it. Today it is low, very low. At -14 I dont think dex would freeze would it ? If it did then I probably do have coolant in the oil. Either the head gasket blew on startup that morning, or the block cracked. Checking oil in the morning. I think that after all this on this 211,000 mile motor the old girl might be done. Too many issues for an engine rebuild.

just some things to review about your engine. lets say you changed your coolant . you flushed out the engine drained the radiator[removed lower hose ] then installed 50/50 dexcool. if that was done then the block will freeze. reason is 2 gallons of water will be trapped in the engine as it cannot be drained . well it can be drained possibly if you can remove the threaded 7/8 allen hex lock tighted into the block at the rear on each side of the engine.

That could be a possibility. I installed a new water pump summer before last. I didn't flush the system but remember that I was putting coolant in so often that I used water a couple of times to keep it full. After the new pump I filled her up with 50/50 but the diluted mixture was still in there, and it never got this cold last winter. I haven't been able to drain the oil yet but checking the level is normal but it smells like fuel. Just changed it this fall.

I just want to add to this thread thanks for all the replies ! I have had this suburban for about 10 years now and have had very few problems with it. Changed both hub assemblies on front, fuel pump, 4 rotors,water pump and a recent brake line. She has been a tough truck !!!!

That could be a possibility. I installed a new water pump summer before last. I didn't flush the system but remember that I was putting coolant in so often that I used water a couple of times to keep it full. After the new pump I filled her up with 50/50 but the diluted mixture was still in there, and it never got this cold last winter. I haven't been able to drain the oil yet but checking the level is normal but it smells like fuel. Just changed it this fall.

if you had a leak and added 50/50 then just water then the block froze.

I measure the drain on my 2000 5.3L and the most I get out with the heater core blown out as well is 1.75 gallons.

since I cannot drain the block I can only go by the GM spec which is around 4 gallons or 16/17 qts..

50/50 freezes at about 30 below zero F . if it was 10 below zero F, this is why I believe it froze since a little over 2 gallons is in the block trapped.
At every coolant change the heater hoses are removed at the block and they are flushed out and blown out.
so on my coolant fill I use 1.25 gallons Dexcool and then .50 gallons of distilled water. I want 65% dexcool not for freeze but for corrosion issues with these engines.

many get tricked out with this on vehicles that got flushed and then added 50/50 and not measuring what they drained out to compare with the manufacturer spec on a total capacity.

on the fill you run engine with coolant cap off until at operating temp then rev engine to 2KRPM for a few times to purge out the air bubbles.

removal of the oil drain plug on a cold engine just for a second will reveal any coolant/water as the oil floats and the water will be at the bottom of the oil pan ..thats when it has settled out after sitting several hours.

if you had a leak and added 50/50 then just water then the block froze.

I measure the drain on my 2000 5.3L and the most I get out with the heater core blown out as well is 1.75 gallons.

since I cannot drain the block I can only go by the GM spec which is around 4 gallons or 16/17 qts..
I would suggest you purchase something like ATD 1106
http://www.amazon.com/
Around $9.95 works on Dex Cool plus shipping. Remember the rubber only lasts 1 or two years. Where you live its well worth the price.