Need Advise, Low Oil Pressure and Lifter Noise

[BigDatx]

Hello All,

New member and looking for advice from people familiar with Tahoe and Chevy's. Been wrenching on cars since I was a kid but I'm new to the Tahoe.

2004 Tahoe LT AWD 5.3 Vortec 190k

I'll start from the beginning. Driving to work one morning and heard loud engine noise, almost a clunking. At the same time the motor lost power. I had to stay on the gas to keep it running. I managed to get off the road and into a side neighborhood very close to my house and I decided to try to limp it home. Halfway there the problem vanished like it never even happened. I thought wth? Maybe a bad sensor or something? As the problem had gone away completely I figured I would have to keep driving it until the problem reproduced itself.

Flash forward a week and I do a scheduled oil change. A day or two later I notice I have lower oil pressure than normal at idle ~20 psi (according to indash gauge) but no engine noise or any other symptoms. Pressure is normal while driving. I thought maybe I got a bad filter and swapped it but the pressure did not go back to normal. A day or two later I was getting off the highway after a ~70mi drive and when I pull up to the light (by my house luckily) the oil pressure drops to almost zero and I get the low pressure warning in the info center. At the same time I start hearing valve noise.

I took the Tahoe to a shop so they could verify oil pressure with mechanical gauge. They confirmed it was way too low.

I then dropped the oil pan to check the pickup tube screen and see if there was anything wrong there. Inside the pan there was a small amount of what I suspected to be gasket material but nothing clogging the pickup tube. At this point I'm suspecting that the bearings and/or lifters are shot but my old man insisted that I replace the oil pump first.

So I just replaced the oil pump, cleaned the pan, new gaskets/o-rings etc. etc. Fired the engine up and I've still got almost no oil pressure and that same noise.

My questions to all you wonderful people are:

-Am I right in suspecting the bearings and/or lifters are shot?
-Any known issues associated with what I described?
-Should I pour some ATF or engine cleaner (seafoam etc) in there and see if it helps?

I'm kind of stuck between a rock and hard place with this truck. Not sure I want to invest in a rebuilt motor or rebuild this one. Not sure if I should just trade her in and take the hit on the value. Maybe some engine cleaner and take her right to the stealership?

Thank you much in advance,

Dan

 

[01ssreda4]

Sounds like it may have been a failing pump and when you continued to drive it, you took out the bearings. I think a pump initially would have fixed it, now I guess not.

 

[rockola1971]

190k original miles to the engine and it died? That engine was abused or a premature failure of a part (Oil Pump) most likely due to lack of maintenance (oil changes). A bad lifter will not cause your oil pressure to be low. It will cause a ton of valve noise. All GM owners should already know that GM engine WILL NOT tolerate low oil pressure. Its just their nature and has always been that way. Bearings...Youll spin em. Rods...Youll chuck em, right out the side of the block.

If you want a beater with a heater to drive then just toss a used 5.3L in there on a weekend. They are cheap and EVERYWHERE.

 

[BigDatx]

Thanks for the replies. Figured it was fubar. Just bought the truck a year ago so I can't speak to the previous owner's maintenance or driving habits but like rockola1971 said I expected to get a little more out of her than 190k. Guess I'll throw in another 5.3

Thanks again.

Dan

 

[rockola1971]

190k is ridiculously low for a 5.3L. Just go here car-parts.com to find you a used one in your area. Grab one with nearly the lowest miles you can find for the price you can afford. I get mine down south of Oklahoma City when I go down there on business. Last time I picked 2 up for $500 for the pair. That was around 4 or 5 years ago. Previous owner probably didnt do the oil changes in a timely manner. Get her going again and come here if you have any problems or need any advice for tools, parts, etc. Theres plenty of us here that have swung a 5.3l or two from a engine hoist.

 

[BigDatx]

Thanks rock, nice resource, already found a couple that look good and affordable!

 

[bottomline2000]

How did the oring on the pickup tube look when u replaced it? What color is the new one? That is a common failure.

Continued driving with no oil pressure may have killed it. I've used carparts.com and it's a great way to find parts..even if u have to ship.

Sent from my SAMSUNG-SM-T377A using Tapatalk

 

[Nashoba]

I may be redundant in again saying that owners should not comply with the owner manual oil change schedule. It is far too long an interval for the health of your engine. I speak from experience because we tried to follow the recommended interval in our 2008 Tahoe Hybrid and we had to spend about two grand getting everything repaired at about 88k. Since then we have dropped back to every three to four thousand miles between changes. No problems since then other than a leaking pan gasket. Also, we never let the oil life reading get below 50%.

 

[rockola1971]

I may be redundant in again saying that owners should not comply with the owner manual oil change schedule. It is far too long an interval for the health of your engine. I speak from experience because we tried to follow the recommended interval in our 2008 Tahoe Hybrid and we had to spend about two grand getting everything repaired at about 88k. Since then we have dropped back to every three to four thousand miles between changes. No problems since then other than a leaking pan gasket. Also, we never let the oil life reading get below 50%.

If you are using conventional motor oil then 3-4k before a change is ok. I dont know why anyone would put anything other than synthetic in their engine now a days. Its not expensive like it use to be when it first came out. If you add the cost up of oil, oil filters , time and its cheaper to run synthetic because you can easily get 8-10k on one oil change. I wouldnt put too much stock into you oil life reading. Its nothing more than a counter that counts down as the engine is running (AKA Engine hours) coupled with a algorithm within the PCM that monitors engine conditions (throttle, load, temp, etc.) to decrease the life % accordingly. There is not a sensor that measures oil viscosity, etc. to check on true condition of the oil. I run synthetic and dont even pay attention to the oil change %.

 

[01ssreda4]

I would NEVER go 8-10k on an oil change.