How Many Miles Does A 2000 GMC Sierra Last? Here is what happens at 250K…

These trucks can last forever… if they are taken care of. The 2000 GMC Sierra 1500 was available with 3 different engine options, a 4.3L V6, a 4.8L V8 and a 5.3L V8. My truck has a 5.3L and these things are really eternal.

It is common for 2000 GMC Sierra pickups to perform as expected up until about 300,000 miles. This is possible with routine maintenance and minor repairs once in a while. Because these GM engines are so well built, they are known for excellent performance for extended lengths of time, comparable to Honda or Toyota engines.

Keeping it ticking will require regular maintenance, which means regular oil and filter changes as well as replacement of seals and bearings. Keeping an eye on other fluids and transmission fluid and filter is another less regular maintenance item that will come up at some point.

Regular Maintenance Of Your GMC Sierra

The inconvenience of having to take time to take the truck into the shop to have the oil changed can be annoying but knowing that this simple investment of time can add years to the truck’s service is worth it. Let’s take a look at some items of maintenance that can make all the difference between the truck killing over within 120,000 or over 300,000 miles.

Regular Oil Changes Add Years To The Truck

Engine Oil

Engine oil is probably the most common and the most important thing to keep your eye on and get it changed every 3,000 miles. The engine oil gets close and personal with all the moving parts in the engine. It is also what keeps those parts from rubbing together and completely destroying the engine.

I’m known to push my oil changed to 6,000 miles on occasions but I would not recommend going any longer that that, ever, if you want the engine to last.

An oil change is something simple that can be done in your own garage within 20 minutes. Many prefer to take it into a shop and have it done for them for under $100. To each their own but I do my own oil changes.

To do this yourself you can look it up on YouTube easily. You will need to buy 5 quarts of Full Synthetic engine oil and an oil filter. It can be a messy job if you are not used to changing the oil your self. I usually have some gloves and rags available near by. A drip pan will be needed to catch the old oil and then the old oil filter.

Prepare The Truck

  1. Park your truck on a level surface and apply the parking brake.
  2. Lift the front of your truck with a jack and place on jack stands.
  3. Remove the oil fill cap from the top of the engine, to allow air to come in as oil will be draining out to release vacuum.
  4. Position the oil drain pan under the oil drain bolt on the back of the oil pan.

Drain The Old Oil

  1. Carefully loosen the drain bolt with the wrench and then unscrew it with your fingers
  2. As you get to the end of the threads, slow down and keep pressure on the bolt to keep the oil from coming out.
  3. When you can tell that the bolt is out of the hole, remove it quickly and let the oil drain into the pan.
  4. Let the oil drain for about 5 minutes or until you see that the oil has pretty much stopped dripping out.
  5. At this point you can wipe off the drain hole area and the bolt and then screw the bolt back in.
  6. Tighten it firm but hand tight. Don’t over tighten it.

Replace Oil Filter

  1. You can now reposition the pan under the oil filter.
  2. Normally the oil filter should not be tightened too tight. Most times you should be able to remove it with your hand.
  3. If it is too tight, you will need an oil filter removal tool.
  4. As you start unscrewing the oil filter, oil will start pouring from above it so try to keep it clean and dripping into the pan.
  5. Once the filter is removed, I just flip it over right into the drain pan and let it lay there until i’m ready to deal with it.
  6. Let the oil drain from the oil filter area for about 5 minutes.
  7. Once it is done dripping, wipe off the seal surface and screw in the oil filter.
  8. You should screw it in hand tight, as tight as you can without using any tools. That is enough tight so you can remove it without a tool next time.
  9. You are now done under the truck.

Fill New Oil

  1. Now use a funnel and pour about 4 quarts of oil in and let stand for about a minute or two.
  2. Pull the oil dip stick out and wipe it off. Then stick it back in and check the oil level.
  3. Keep pouring the oil in until the level is within the markings on the dip stick.
  4. Close the fill cap, take the truck off the jack stands and lower it to the ground and you are done.

Keeping The Coolant Levels Topped Off

The coolant is what keeps the engine – cool. Making sure that the level is within the markings on the expansion tank insures that there is enough coolant to keep it circulating efficiently and keeping the engine within the correct operating temperatures.

Coolant is not a consumable component so it shouldn’t normally need to be added unless it is leaking somewhere or the engine has warped heads or damaged head gaskets letting coolant into the cylinders. Under normal circumstances, check the coolant levels when you change the oil just to keep an eye on it.

If you look at the side of the coolant tank, you will see 2 lines, one has marking next to them saying MAX and MIN. You want to keep the coolant between those lines. If it is low add some more but don’t fill it higher than the MAX line.

The coolant you should use is the one that has 50/50 label on it. This means it is already diluted and ready to go into the coolant tank.

Check And Top Off The Transmission Fluid

Transmission Fluid

The transmission fluid is purple and it makes the transmission lubed up and makes it switch gears. Low levels of transmission fluid can result in it not switching into certain gears or make weird sounds.

It is easy to check the level of transmission fluid, there is a dip stick for that under the hood.

To check the transmission fluid levels, do the following:

  1. Drive the truck for about 20 minutes to get the fluid up to the operating temperature.
  2. Switch the gears shifter into each gear including the reverse and neutral.
  3. Put the truck into park, apply the parking brake and keep the engine idling.
  4. Pull the red transmission dip stick out and wipe it off.
  5. Push it back in all the way and pull it back out.
  6. Check the level. The fluid should be within the cross hatch on the dip stick.
  7. If it is lower, insert a funnel right into the dip stick tube and add some fluid.
  8. Check the levels again and when done, push the dip stick back in and you are done.

Check The Steering Fluid

Just like brake fluid, steering fluid is also not a consumable fluid and should always be within the operating range level. If it gets lower, means it is leaking somewhere and should be checked out by a mechanic. There are markings on the reservoire attached to the steering pump which lets you see the levels and keep it within those markings.

Check The Brake Fluid

Brake fluid is not a consumable component. It normally does not need to be filled unless for some reason it is leaking somewhere. There is a white plastic reservoir under the hood attached to the main brake cylinder with markings on it that show where the brake fluid level should be. Keep an eye on it to make sure it is within the markings.

Check The Brakes

Brake Pads

Brakes are something that will be checked while installing new tires by the tire technician. They do this routinely so they will be your first line of defense that will alert you to the need of brake pads replacement. Otherwise, if you hear a high pitch squealing sound coming from your wheels, you will know that the brake pads are getting low. You can replace these yourself or have the tire company do it while you have them rotate your tires.

If the brake pads get too low and metal starts scraping against the rotors, you can lose your brakes, but you will also overheat the rotors which will warp them which will make your car shake while braking. Metal against metal will also dig grooves into the rotors that will eat through the brake pads a lot faster. This will require replacing the rotors.

Seals And Bearings

There are many seals in the truck that keep the oil and fluids from pouring out while operating. These seals can fail after years of operation. The way to tell if you have a seal that needs to be replaced is to keep an eye out for oily splatter on the bottom of the truck.

Here are a list of seals that commonly fail after 120,000 to 150,000 miles.

  1. Main seal (rear of the engine, between engine and transmission).
  2. Front main seal (front of the engine behind the balancer).
  3. Rear transmission seal (between transmission and transfer case).
  4. Input and output seals on transfer case.
  5. Input seal and axle output seals on front 4×4 transfer case.
  6. Differential pinion seal (where the drive line enters into the differential).
  7. Rear axle seals (on each side of the axle where the axle enters the axle housing).

Here are bearings that may also need to be replaced if you hear noise coming out of these locations:

  1. Front axle bearings (on each side of the axle, behind each of the front wheels).
  2. Rear axle bearings (On each side of the axle, behind each of the rear wheels).
  3. Differential pinion bearing (where the driveline enters the differential).
  4. Differential case bearings (inside the axle housing on each side of the differential case).

One Off Repairs That Can Come Up On The Way To 300,000 Miles


Other things that may fail on the way to 300,000 miles can be anything but the more common things to keep in mind are listed below:

  1. Transmission can fail – if abused and not maintained
  2. Transfer cases (4×4) – if abused and not maintained
  3. Head gaskets – if engine is overheated
  4. Interior of the truck, seat upholstery, dash cracks
  5. Paint can fade
  6. Fuel pump can fail (not any specific reason, just from age

These components and more can fail through the life of a truck but if the truck is maintained regularly, the chances of multiple systems failing at the same time – making the truck too expensive to fix, is unlikely. It will be small things here and there that will need work over a long period of time. The nice thing is that the truck will continue to serve you for years and years.

My Old 2000 GMC Sierra 1500 With 250,000 Miles

My 2000 GMC Sierra

This old truck was abused like I’ve never seen before. I bought it in 2021 with 256,000 miles on it for $1800. The engine was so greasy and every seal on it was shot and all kinds of grease was all over the under side of the truck. The oil pressure gauge showed 0 but occasionally would go up to 4 while idle. the interior is filthy and the drivers side seat has a hole in it. The body on it was for the most part ok, with a few dings and peeling clear coat.

I personally don’t think anything was ever done on it since it came off the assembly line back in 2000. The poor guy I bought it from didn’t know what to do with it. He must have bought it and thought he could fix it but when he dug into it and found everything that was wrong with it, gave up.

Fortunately, I was looking for exactly this kind of piece of cow pucky. I wanted to restore a truck like this from scratch. The price was right so I bought it.

This truck is a good example of what happens to one if you never maintain it. It still reached 256,000 miles but was ready to croak. Good thing I came around and saved it. I’ll tell you about the restore process in a future post.

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