I stumbled upon this 2001 Chevy Silverado 2500HD 4X4 last spring on Craigslist. The listing was very short and did not include any pictures, to sum it up it was listed as “Needs motor, still runs, good tranny, 4WD, tow hitch, power windows”. There was no phone number, so I fired off an email to see if there was a chance of getting any pictures and to find out if it was a 2500HD or a 2500, since the ad did not specify. If it was a 2500, I would have passed on it, being that the transmission would have been a 4L60E, not a 4L80E which came standard on the 2500HD. Fortunately, it was a 2500HD and the seller was able to send me some pictures,of the interior and exterior.

The seller also included a phone number, so after viewing the pictures, I called to find out the real scoop on the truck, since I had no idea why the motor needed to be replaced, nor did I know how many miles it even had. The phone call shed some light on why the truck was only $1700 and why he was selling it instead of fixing it. Turns out, the truck had 340,000 miles on it and the reason it needed a new engine was because it had no oil pressure unless you kept the RPMs raised for a bit or until the truck warmed up.

I started researching the problem and to my surprise, found that it was a fairly common issue with the LS engines. Most of the things I read reported the low oil pressure issue was a result of a cracked o-ring where the pickup tube meets the oil pump. There were a few reports of the oil pressure relief valve getting stuck partially open from debris in the oil, causing low or no pressure. Both of these issues appeared cheap and easy to fix, so with that, my decision to purchase the truck was made.

I met the seller on a Saturday morning to inspect and hopefully purchase the truck. I did a brief walk around but was not really concerned with the body since it was and will continue to be a work truck. After getting the keys, I fired the truck up. It was clear that no only did it have little to no oil pressure, but the power steering pump was whining louder than anything else so it was difficult to hear what noises the engine was making, if any. Overall, I was pleased with the truck and felt it was worth a shot, worst case scenario being either to part it out or use it to fix a different truck. The deal was made and I loaded it up to bring it home.

Once home, I topped off the power steering fluid to get that to quiet down and got it off to trailer to see how it drove and stopped.

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I did not want to run it for long in its current condition, so after a quick drive to make sure it shifted, stopped and turned without problems, I parked it and proceeded to scan the engine, transmission and ABS systems to see if any codes were present. There were a few codes but nothing substantial or unexpected, they would all be dealt with in time. Now it was time to come up with a game plan, get it washed and order parts. First on the list was to get everything ordered to take care of the oil pressure problem and the PS leak. A timing cover gasket set was ordered, which included the oil pickup tube o-rings, a timing chain since the old one had so many miles on it, a power steering pump, belt, air filter, oil filter and oil. Most of the parts we’re in stock, but a couple were a day out and the chain for whatever reason was a few days out, so I had time to play around with the cosmetics a bit.

After I got the the truck washed, it was apparent that the truck had the bed and both passenger side doors replaced at some point in its life. I knew it had been wrecked when I went to look at it, regardless of the sellers story of how the pillar got bent up like it is. Nevertheless, the bed did not have the rear flares like it should, the passenger mirror was a manual mirror instead of a power mirror and the drivers side mirror was held together with a sheetrock screw. I hit the interweb to search the local yards for the parts and sure enough, I was able to locate a pair of mirrors about 45 mins away for $35 and a pair of rear flares for $80, 10 minutes away from that place. One road trip later and I had some used parts. The truck was missing the side molding from the passenger front door, so I decided to remove the rest of the trim rather than replacing it. Unfortunately the replacement parts that were installed on the truck were originally white, so a little bit of Duplicolor magic was going to be required.

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Now that my engine parts arrived, it was time to dig into the engine and see what we could find. I had the front of the engine torn down and the oil pump removed by lunch time. I found that the oil pump o-ring was not cracked, but it had shrunk. The red o-ring pictured next to the original green o-ring is actually a size down from what it was supposed to be. There are at least three different o-rings used on the LS engines, Green, Red and Black were included in this gasket set. Before replacing the o-ring and slapping it back together, I took the pump apart and removed the pressure relief valve. The pump itself looked to be in good shape. The pressure relief valve moved, but it was evident there was some debris starting to build up in there. Everything was cleaned and reassembled, then installed into the truck along with the new timing chain. Once the cover and crank pulley were installed, the PS pump was swapped out and installed along with a new belt. The air and oil filters were replaced and last but not least, some high mileage synthetic Mobil 1 was poured in. With my fingers crossed, I turned the key and……. presto! 60 PSI of oil pressure. A little valve tap in the beginning and then it smoothed right out. Mission accomplished.

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Now that the truck runs like it should and looks like it should, a few other things needed some attention in order to call it complete. Next on the list was replacing the 5-pin trailer harness with a 7-pin harness and replacing the fuel level sender that seemed to work intermittently. Neither one was a difficult task, just a little time consuming.

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All that was left to be done was slap on the new center caps that arrived in the mail, sell my old truck and transfer the plates.

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After these pictures were taken, I tinted the back window, replaced the rear brake pads and sold my old truck for $250 more than I paid for this one, which just about covered the cost of this truck and the parts required to fix it. So far its been 4 months, I’ve put about 1,000 miles on the truck with no issues at all.


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