2000 GMC Sierra 1500 ?'s

beeline08 · June 14, 2018

Hey everyone. I am the new owner of a 2000 GMC 1500 stepside extended cab 4x4 pickup with 161,000 miles. I checked it out the best I knew how before I bought it. Motor seems to run strong and smooth. One time out of several drives it did kind of chug a little bit when returning to idle but began to idle normally again. Transmission shifted smooth through all gears and fluid looked almost new. I am not sure but I can only hope the the tranny has already been replaced. My question is what all can I do to make sure she is running as well as she can. Plugs, wires, etc. are the kinds of things I am looking for. I am not looking to mod it out but anything to run smooth and slight performance increase wouldn't hurt. She is going to be my weekend warrior hunting/fishing rig. Thanks in advance for any info!

Supreme Pizza · June 14, 2018

New rig? Here is what I do:

Plugs

Wires

PCV valve

Fuel filter

Air filter

Fuel injector cleaner

Change the motor oil

Check the differential and transfer case fluid levels asap, and look for any leaks under there - including from the shocks.

Check all the fluid levels under the hood daily, and learn the consumption rate. Never let them get low.

Jack up the front of vehicle and check for wheel bearing play.

Scan the computer or have an auto parts store do it for free.

Check the tire pressure, and wear characteristics.

Look for stop leak in the radiator, and confirm that the system is holding pressure when the engine is hot. Check for cooling fan bearing play.

Confirm that the 4x4 works, by flooring it on gravel. Don't wait for snow to see if it works.

Install a hidden kill switch to either the fuel pump or starter. (anti-theft feature).

Change the cabin air filter.

I usually prioritize these items, and tackle them as soon as possible. If the front or rear diff is low on fluid it - could cause thousands of dollars worth of damage. Gear oil is very cheap, and a lack of gear oil is very expensive.

greatmizzou · June 14, 2018

the two biggest issues you may want to remedy for futre proofing will be fuel line rust and brake line rust

I dumped thousands and thousands of $$$ intoy truck the last two years to make it a reliable tow vehicle and the brake and fuel lines were the only two things that left me sitting on the shoulder. Everything else was ride quality and peformance enhancements

Supreme Pizza · June 14, 2018

1 hour ago, greatmizzou said:

the two biggest issues you may want to remedy for futre proofing will be fuel line rust and brake line rust

I dumped thousands and thousands of $$$ intoy truck the last two years to make it a reliable tow vehicle and the brake and fuel lines were the only two things that left me sitting on the shoulder. Everything else was ride quality and peformance enhancements

I had to replace the brake lines on one of my Suburbans, because it came from back east.

The complete brake line kit cost $55 on eBay, and took a couple hours to install.

Vehicles in Washington state do not have the rust issues, so my other vehicles are fine.

If you want to stop the rust and protect the lines, spray them with this stuff every year on your birthday.

beeline08 · June 15, 2018

Thanks for the tips. Most of that I had thought about but not like the pcv valve. The diffs are another thing that I will focus on.

I will check these lines for sure. Wouldn't have known about that. We don't get much winter weather in Alabama so typically that's not an issue. I did check the frame and everything on the bottom and didn't see any rust. According to the vehicle report it hasn't been out of Alabama and Mississippi.

beeline08 · June 27, 2018

I have got to most of this except the plugs and wires. It still idles at around 500 and wants to bog down a little when you stop and then idle fine again. What else could cause this?

Supreme Pizza · June 27, 2018

I would do the full tune up before trying to diagnose anything. It could have the wrong plugs in it, wrong plug gap, worn out plugs, fouled plugs, etc.

beeline08 · June 28, 2018

I got to the plugs last night. You are right. They were NGK plugs and looked totally different than the AC Delcos I had to put in. Found something very disturbing. Cylinder 1 plug wasn't even screwed in tight and had what looked like oil all over it. Put the socket on it and immediately spun free. So what kind of terrible news does this imply? Have had no CEL on.

sefiroxx · June 28, 2018

Blow by gases escaping through spark plug hole. Loss of compression and thus loss of a hp. The oil may have interfered with spark - but should have thrown a code.

Had the same problem with my 01 4x4 burb, turned out to be the idle air control valve. Had done full tuneup, replaced tps, may etc - the other common causes of low idle.

Supreme Pizza · June 28, 2018

The plug being loose means nothing. Someone didn't tighten it properly - no big deal. As for the oil on the plug, was the oil on the tip? Was there oil outside of the plug hole? If so, it may have leaked down the threads to the tip of the plug.

I would drive it for a week, and pull the plug out again to see if its covered in oil.

If the tip of the plug keeps getting oily and fouled, then you either have: Worn valve guide seals, or worn piston rings, scored cylinder wall, etc.

There is also a TSB about the PCV valves on that rig. The old PCV valve is superseded by a new design that limits the amount of oil that gets drawn into you cylinders.

If your valve guide seals are bad, you could try ATP-205. That may resolve the issue.

I own 2 of the same engine.

sefiroxx · June 29, 2018

Ditto starman. (My post only focused on the immediate effect of a loose spark plug , if tightened down and still fouled - then follow starman)

beeline08 · June 29, 2018

so this ATP-205 is safe to use? i have always been told these types of products are not good for the engine.

Supreme Pizza · June 29, 2018

1 hour ago, beeline08 said:

so this ATP-205 is safe to use? i have always been told these types of products are not good for the engine.

You are correct that most "stop leaks" are not good for your vehicle. Radiator stop leak, engine stop leak, tire stop leak, etc. None of those are very good to use however, ATP-205 in not the same an normal engine stop leak products.

Normal engine stop leak products cause rubber to expand, which could close up any gaps, but it can also pop the seal out and now you have a HUGE leak.

ATP-205 works differently. When seals get old, they become hard, rigid, shrink and crack. The reason this happens is because there is a special chemical in the rubber that basically evaporates over time. That special chemical is what keeps the rubber soft and pliable. Well, ATP-205 is 100% "special chemical". So it soaks into hardened rubber seals and returns them to their original soft condition. It will not replace missing rubber, and it will not cause the rubber to expand, so that means it doesn't work every time. If your seal is completely shot, it wont help at all on that particular seal, but it will benefit the other seals in the engine.

I would never use regular engine stop leak products, but I have used ATP-205 in several engines, one transmission, and a front axle. I have had very good results. If your valve guide seals are not working very well, this product may restore them and eliminate the oil burning. It certainly wont hurt anything.

There are a million Youtube videos about this product. I have seen most of them, and people say good things about it.

The manufacturer website has videos on it, but the Youtube videos are more credible to some people.