Oil Pressure Problems Please Help

[jn452]

Hi I am new here but would like some help with a problem I am having with my 2004 Chevy 2500. I have the 6.0 LQ4 motor with a NV 4500 manual tranny and about 200000 mile on it. My problem is that in the mornings when I first fire my truck up cold (in texas cold is 70 ) i have little to no oil pressure, about 0-10 psi. The oil pressure will not raise with engine rpm like it is suppost to. I have even experenced bad lifter knocking twice because i did not wait for the oil pressure to raise before I left for work. However after 10 to 15 minutes oil pressure will shoot up to 20 psi at idle and 35-40 at high way speeds and remain there the rest of the day. I work construction so i am driving from job to job throughout the day and the truck never really cools down betrween stops I think this is why the oil pressure is good throughout the day. I can not think of anything else besides the o-rings in the pick up tube that can cause this. Am I wrong what else is there. Please help I love my truck and have no desire or money to replace it. I have no problem tearing it apart to fix it but do not want to tear it apart till I know exactly what I need to fix. Thanks

[bossier62guy]

Hi I am new here but would like some help with a problem I am having with my 2004 Chevy 2500. I have the 6.0 LQ4 motor with a NV 4500 manual tranny and about 200000 mile on it. My problem is that in the mornings when I first fire my truck up cold (in texas cold is 70 ) i have little to no oil pressure, about 0-10 psi. The oil pressure will not raise with engine rpm like it is suppost to. I have even experenced bad lifter knocking twice because i did not wait for the oil pressure to raise before I left for work. However after 10 to 15 minutes oil pressure will shoot up to 20 psi at idle and 35-40 at high way speeds and remain there the rest of the day. I work construction so i am driving from job to job throughout the day and the truck never really cools down betrween stops I think this is why the oil pressure is good throughout the day. I can not think of anything else besides the o-rings in the pick up tube that can cause this. Am I wrong what else is there. Please help I love my truck and have no desire or money to replace it. I have no problem tearing it apart to fix it but do not want to tear it apart till I know exactly what I need to fix. Thanks

 

Are you sure it's not just an indication problem?

[jn452]

Hi I am new here but would like some help with a problem I am having with my 2004 Chevy 2500. I have the 6.0 LQ4 motor with a NV 4500 manual tranny and about 200000 mile on it. My problem is that in the mornings when I first fire my truck up cold (in texas cold is 70 ) i have little to no oil pressure, about 0-10 psi. The oil pressure will not raise with engine rpm like it is suppost to. I have even experenced bad lifter knocking twice because i did not wait for the oil pressure to raise before I left for work. However after 10 to 15 minutes oil pressure will shoot up to 20 psi at idle and 35-40 at high way speeds and remain there the rest of the day. I work construction so i am driving from job to job throughout the day and the truck never really cools down betrween stops I think this is why the oil pressure is good throughout the day. I can not think of anything else besides the o-rings in the pick up tube that can cause this. Am I wrong what else is there. Please help I love my truck and have no desire or money to replace it. I have no problem tearing it apart to fix it but do not want to tear it apart till I know exactly what I need to fix. Thanks

 

Are you sure it's not just an indication problem?

 

 

Yes I have installed a manual oil pressure gauge and the readings i gave before came from this. I have no faith in any factory gauges on this truck have repaced the oil sending unit 3 times and had to replace the entire gauge cluster 1. before i installed the manul oil gauge the factory gauge read 30 psi at idle when cold and 40 psi when warm and runnig right and 65 psi when running down the hi way.

[bossier62guy]

Hi I am new here but would like some help with a problem I am having with my 2004 Chevy 2500. I have the 6.0 LQ4 motor with a NV 4500 manual tranny and about 200000 mile on it. My problem is that in the mornings when I first fire my truck up cold (in texas cold is 70 ) i have little to no oil pressure, about 0-10 psi. The oil pressure will not raise with engine rpm like it is suppost to. I have even experenced bad lifter knocking twice because i did not wait for the oil pressure to raise before I left for work. However after 10 to 15 minutes oil pressure will shoot up to 20 psi at idle and 35-40 at high way speeds and remain there the rest of the day. I work construction so i am driving from job to job throughout the day and the truck never really cools down betrween stops I think this is why the oil pressure is good throughout the day. I can not think of anything else besides the o-rings in the pick up tube that can cause this. Am I wrong what else is there. Please help I love my truck and have no desire or money to replace it. I have no problem tearing it apart to fix it but do not want to tear it apart till I know exactly what I need to fix. Thanks

 

Are you sure it's not just an indication problem?

 

 

Yes I have installed a manual oil pressure gauge and the readings i gave before came from this. I have no faith in any factory gauges on this truck have repaced the oil sending unit 3 times and had to replace the entire gauge cluster 1. before i installed the manul oil gauge the factory gauge read 30 psi at idle when cold and 40 psi when warm and runnig right and 65 psi when running down the hi way.

 

 

I'm not sure what's causing your problem then but I don't think I'd be running my engine that long w/ the oil pressure that low. It's possible the pump itself is going south w/ that many miles on it. Maybe someone that has experienced your problem will speak up and offer some advice. Good luck and keep us posted on the outcome.

[jn452]

Hi I am new here but would like some help with a problem I am having with my 2004 Chevy 2500. I have the 6.0 LQ4 motor with a NV 4500 manual tranny and about 200000 mile on it. My problem is that in the mornings when I first fire my truck up cold (in texas cold is 70 ) i have little to no oil pressure, about 0-10 psi. The oil pressure will not raise with engine rpm like it is suppost to. I have even experenced bad lifter knocking twice because i did not wait for the oil pressure to raise before I left for work. However after 10 to 15 minutes oil pressure will shoot up to 20 psi at idle and 35-40 at high way speeds and remain there the rest of the day. I work construction so i am driving from job to job throughout the day and the truck never really cools down betrween stops I think this is why the oil pressure is good throughout the day. I can not think of anything else besides the o-rings in the pick up tube that can cause this. Am I wrong what else is there. Please help I love my truck and have no desire or money to replace it. I have no problem tearing it apart to fix it but do not want to tear it apart till I know exactly what I need to fix. Thanks

 

Are you sure it's not just an indication problem?

 

 

Yes I have installed a manual oil pressure gauge and the readings i gave before came from this. I have no faith in any factory gauges on this truck have repaced the oil sending unit 3 times and had to replace the entire gauge cluster 1. before i installed the manul oil gauge the factory gauge read 30 psi at idle when cold and 40 psi when warm and runnig right and 65 psi when running down the hi way.

 

 

I'm not sure what's causing your problem then but I don't think I'd be running my engine that long w/ the oil pressure that low. It's possible the pump itself is going south w/ that many miles on it. Maybe someone that has experienced your problem will speak up and offer some advice. Good luck and keep us posted on the outcome.

 

 

thanks for your help. I always check the oil pressure when i start and if it is below 6 psi at idle i kill it. It almost always has 6 psi witch is the manufactures minimum at idle. it just will not increse with engine rpm like it is supost to untill it has run 10 to 15 minutes. I change my oil every 10000 miles with royal purple and lucas full synthetic. compression is still great and after oil pressure if good it runs every bit as good as the day i bought it. I just do not want to destroy it running with too little oil pressure.

[bossier62guy]

Hi I am new here but would like some help with a problem I am having with my 2004 Chevy 2500. I have the 6.0 LQ4 motor with a NV 4500 manual tranny and about 200000 mile on it. My problem is that in the mornings when I first fire my truck up cold (in texas cold is 70 ) i have little to no oil pressure, about 0-10 psi. The oil pressure will not raise with engine rpm like it is suppost to. I have even experenced bad lifter knocking twice because i did not wait for the oil pressure to raise before I left for work. However after 10 to 15 minutes oil pressure will shoot up to 20 psi at idle and 35-40 at high way speeds and remain there the rest of the day. I work construction so i am driving from job to job throughout the day and the truck never really cools down betrween stops I think this is why the oil pressure is good throughout the day. I can not think of anything else besides the o-rings in the pick up tube that can cause this. Am I wrong what else is there. Please help I love my truck and have no desire or money to replace it. I have no problem tearing it apart to fix it but do not want to tear it apart till I know exactly what I need to fix. Thanks

 

Are you sure it's not just an indication problem?

 

 

Yes I have installed a manual oil pressure gauge and the readings i gave before came from this. I have no faith in any factory gauges on this truck have repaced the oil sending unit 3 times and had to replace the entire gauge cluster 1. before i installed the manul oil gauge the factory gauge read 30 psi at idle when cold and 40 psi when warm and runnig right and 65 psi when running down the hi way.

 

 

I'm not sure what's causing your problem then but I don't think I'd be running my engine that long w/ the oil pressure that low. It's possible the pump itself is going south w/ that many miles on it. Maybe someone that has experienced your problem will speak up and offer some advice. Good luck and keep us posted on the outcome.

 

 

thanks for your help. I always check the oil pressure when i start and if it is below 6 psi at idle i kill it. It almost always has 6 psi witch is the manufactures minimum at idle. it just will not increse with engine rpm like it is supost to untill it has run 10 to 15 minutes. I change my oil every 10000 miles with royal purple and lucas full synthetic. compression is still great and after oil pressure if good it runs every bit as good as the day i bought it. I just do not want to destroy it running with too little oil pressure.

 

 

I don't blame you one bit.....I hope someone can offer up some good advice soon! BTW....no check engine light or the engine refusing to start? I would imagine there is some sort of protection to keep the engine from running w/ inadequate oil pressure. How long has it been since you changed the oil? What type of filter are you using?

[jn452]

I use a wix oil filter and my last oil change was about 2500 miles ago. I have never had a check engine light come on. The truck still fire right up. No hesitation still idles smooth every thing is perfect except the oil pressure. I have a new oil pump, water pump, and timing set that I bought last week with the intentions of installing today. However this is an involved process and while I do not mind going in and replacing worn parts I do not want to go in and miss the real problem. I figured as long as I was there I would replace the timing chain and water pump, after all they have a lot of miles on them. In the past i have replaced parts first only to figure out later that their misfunction was only a symptom of a different problem. This is how i spent 1000 bucks trying to get my altornator to work again only to find a brocken wire than only needed to be soddered back. I want to know what to look for and what i will need to fix it right the first time. Or at least all the possible areas to check. Thanks

[bossier62guy]

I use a wix oil filter and my last oil change was about 2500 miles ago. I have never had a check engine light come on. The truck still fire right up. No hesitation still idles smooth every thing is perfect except the oil pressure. I have a new oil pump, water pump, and timing set that I bought last week with the intentions of installing today. However this is an involved process and while I do not mind going in and replacing worn parts I do not want to go in and miss the real problem. I figured as long as I was there I would replace the timing chain and water pump, after all they have a lot of miles on them. In the past i have replaced parts first only to figure out later that their misfunction was only a symptom of a different problem. This is how i spent 1000 bucks trying to get my altornator to work again only to find a brocken wire than only needed to be soddered back. I want to know what to look for and what i will need to fix it right the first time. Or at least all the possible areas to check. Thanks

 

Any chance you can try another gauge? I remember reading somewhere on the website that the computer won't allow the engine to run w/ the oil pressure being that low. Before I replaced the oil pump I think I'd swap out the oil filter (only) and if possible verify that my gauge setup is working correctly. Electric or mechanical gauge?

[jn452]

I could hook up another oil pressure gauge to double check that I am reciecing an acurate reading. I am pretty sure that my truck does not cut its self off if the oil pressure is to low. I have replaced 3 oil pressure sending units over the years. When they go out the gauge will read 0 and the information center will read oil pressure too low or something like that, but the truck will just keep on running. Right now I have the oil pressure sending unit disconected and out of my truck. I have the manual gauge conected to that port and the sending unit sitting on the work bench with the conector on the truck just hangging in the brease, and it has run like that all day. I even took it for a spin today just to get more info on oil pressure durring driving conditions. I can try to change the oil filter, but i have to ask why and if it is the oil filter what brand of filter should i switch to. thanks

[bossier62guy]

I could hook up another oil pressure gauge to double check that I am reciecing an acurate reading. I am pretty sure that my truck does not cut its self off if the oil pressure is to low. I have replaced 3 oil pressure sending units over the years. When they go out the gauge will read 0 and the information center will read oil pressure too low or something like that, but the truck will just keep on running. Right now I have the oil pressure sending unit disconected and out of my truck. I have the manual gauge conected to that port and the sending unit sitting on the work bench with the conector on the truck just hangging in the brease, and it has run like that all day. I even took it for a spin today just to get more info on oil pressure durring driving conditions. I can try to change the oil filter, but i have to ask why and if it is the oil filter what brand of filter should i switch to. thanks

 

Only because I've read other threads that suggested replacing it when oil pressure problems are present. It's a cheap and easy thing to do versus dropping the pan and changing a pump right off. I use Wix filters myself....stick w/ them. I figured someone else w/ a little more knowledge of the engine might jump in by now as well but so far I see that hasn't happened. I do know that the 04's had problems w/ the instrument clusters as well.....amazing that you've been through so many sending units.

[WilliamBos]

It's a cheap and easy thing to do versus dropping the pan and changing a pump right off. I

 

Pretty sure the oil pump is behind the timing cover, no need for a pan drop.

[bossier62guy]

It's a cheap and easy thing to do versus dropping the pan and changing a pump right off. I

 

Pretty sure the oil pump is behind the timing cover, no need for a pan drop.

 

 

It very well might be from the looks of the replacement pump....I have very little knowledge of these newer engines.

[txab]

Your pump could be worn. Also you might have badly worn main and connecting rod bearings in conjunction with the oil pump. Just be sure that your pressure readings are correct before tearing into the engine just to replace the pump

[thearborbarber]

There was a TSB out for the oil pic up tube to pump O ring. I don't remember what years were covered. Th O ring would crack and you would have intermittent oil pressure loss. The oil pump on the LS series engines is on the front of the engine on the snout of the crackshaft. They are a simple and robust design but do fail (very rarely but do fail). Here is an exploded diagram of the oil system on LS engines. 410 is the oil pump asembly.

 

[thearborbarber]

I found the O ring tsb. Dont think it applies to your truck but here is a link non the less.

 

http://www.pistonslap.com/tsb/020601038.htm