The Stovebolt Site Forums The Shop Area The HiPo Shop Dirty little 5.3L L59 Secret

Maybe I'm late here, but I've always heard these LS engines are bullet proof. For you guys considering a swap, apparently it is fairly common for the oil pressure sending unit to crap out, which will definitely get your attention on the freeway when your oil pressure goes to zero ! Happened to me yesterday in my 2012 Sierra, when bells started going off and warnings flashing to stop engine! Still an awesome engine, just wasn't aware this was that common.

Just actually swapped a 03 5.3 into a late 70’s squarebody last week with a close friend. He drove it 2 days and loved it until the sender popped and [censored] out all the oil against the back of the intake/firewall. We pulled it home and put a plug in it and it wont be a issue again. We have the factory mechanical gauge and sender plumbed into a different spot so there was no need for it with that application.

BF....when I pulled the truck into the shop, the desk guy said the technician said it had good oil pressure despite the guage…..do you have any idea how you can confirm pressure without the guage? First thing I did was pull the dipstick to make sure it had plenty oil, but no idea how to get a road side check on pressure.

Im not sure how he verified oil pressure. Could have hooked up to a different port with a mechanical gauge or I believe you may be able to read oil pressure via the obd2 port under dash. That truck probably has AFM so he might have seen oil pressure to that system. Not really sure. If he replaced the sensor and its good now I wouldn’t lose any sleep over it. Ive seen them with the common bad pickup o-ring with s**t oil pressure run for years in jobsite trucks where guys who drove them could care less. I personally ran my 4.8 with like 15psi hot on the highway at 3400 rpm with no overdrive. Car made over 500HP on that setup and never skipped a beat. I pulled it apart 2 seasons later and the bearings looked perfect with I think 200k on them. I popped a new pump and o-ring in it and it shot up to 40psi at idle hHahahahaha. I was like “hmmmm odd”. They are pretty resilient.

Very common and considerably more hassle with Corvettes. On that forum 50% will suggest removing the intake manifold to access it and the other 50% will suggest cutting an access hole in the cowling. Relocation kits are very common to get at it easier.

Your 2012 Sierra has a L59 engine?

Must not have been a G.M. mechanic!

Well they are pretty bulletproof..... but as like anything else mechanical anything can fail. If i said i heard SBC’s were said to be solid but i heard someone called them junks every hotrod guy in the world would be ready to fight. They have tons of failure points and oil leaks and the list goes on. Yes some LS base engines run well over 250k with nothing more than a oil change. Some have oil pickup issues, lifter problems (usually DOD trucks), some head gaskets on earlier ones, piston slap yada yada yada. For the most part they are a reliable engine....i dont even count any sensor or sender as a part of a certain engine anyways. The truck itself may have multiple electrical failures or associated issues but the engine will most likely out live the truck especially in the rust belt. I have personally proven what they can do with over 250k straight outa the junkyard stuffed into a car and force fed to make pretty dang reliable power north of 540hp without ever pulling a head or the pan.

I think that this describes the "problem": https://www.fixmyoldride.com/Chevy-engine-oil-pressure.html

I'm interested since I have the L20 in my 2010 Sierra. The "problem" seems to come from gunky oil so I'm guessing that frequent oil changes would be a good idea if you plan to use a LS engine.

Gord, I think it is actually an LMG. I just sucked it up and had my shop switch it out for $400. Thanks for posting your article, apparently GM realized it was an issue. Contrary to the youtube videos, the GM tech guide advises taking the intake manifold off to get to the sensor. It's right next to the firewall. I made sure the shop used Delco parts including the little screen. I think the learning for me is, if you swap one into your Bolt, just go ahead and spend $30 on Amazon or Rockauto and replace it. Again, these are great engines....I've just never heard anyone mention it before. BTW, I only put full synthetic Mobil1 oil and GM intervals, so don't think it was gunky oil in my case.

If you swap one into anything just plug the hole and never worry about it.