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Chevy Silverado and GMC Sierra Gasoline Engine Problems



  • steelweelssteelweels Member Posts: 4
    91 gmc k2500 4wd, 5.7L, oil cooler adapter leaks at mount of block, gaskets were gone, replaced with new set, not sure how they go though for sure, drove 12 miles everything was fine, next morning 5 miles later, blew again in same spot, need to know what is going on, why, and how to install gaskets correctly, no one around here can say for sure, no money for the shop. thanks
  • jreaganjreagan Member Posts: 285
    I had the same problem on my 2000 GMC Sierra a few years ago. It was the fuel pressure regulator. A really simple fix. It is located near the top of the engine on the fuel rail. I recommend buying it at your local dealer and installing it yourself. They will (they did for me anyway) show you where it goes and how to relieve the fuel pressure in the system.
  • steelweelssteelweels Member Posts: 4
  • jnealjneal Member Posts: 247
    I would guess at either a warped cooler adapter or incorrect torque when tightening.
  • nelson1nelson1 Member Posts: 41
    I am having a semilar starting problem with my 2000 Silverado 1500. If I turn the key to on position, and then off again, and then on again, it will usually kick off right away. If I just turn the key directly to the start position, it will usually set there and turn the starter, and will not start for a few seconds of turning the starter. Then, when it starts, it seems to be choked for a few seconds, and runs rough, before it smooths out. Very aggravating. Haven't decided what to do, yet.
  • geo9geo9 Member Posts: 735
    GUYS.........Sure sounds like the fuel pressure regulator
    to me also. Easy DIY to check.
    1- Locate the FPR
    2- Start engine .let run. Turn off engine.
    Pull vacuum line off nipple on FPR If wet with fuel (gas)
    replace !!!!!!!!!!

    More info at
  • don68don68 Member Posts: 2
  • bcrawfordbcrawford Member Posts: 3
    My buddy has the same truck... 2000 gmc Z71 4x4 200 km. He has the same symptoms as your truck. I am sure that it is a noisy power steering pump. You can feel vibrating when running and touching the power steering pump cap. You can try to drain the oil with a turkey baster or large syringe and replace with a synthetic fluid and a additive.
  • gholdegholde Member Posts: 4
  • shiftless1shiftless1 Member Posts: 9
    If the noise is coming from the belt friction. A simple test is to spray water on the belt while it is running. If the problem is belt friction, the noise will stop immediately!

  • helomekhelomek Member Posts: 4
    1999 4.3l 2wd reg cab short bed,

    At about 70-75 mph I feel hesitaion, like there's not enough gas, ignition bad, or transmission. It idles fine, has get up and go from a stop. Already replaced the fuel pump a while back. As I did with the spark plugs a few months ago, and just replaced the fuel filter, I just had to change my catalitic converters, at 105,000. I do have a lot of miles, but my truck has been good to me and I want to keep it a while.. I have done everything I know. I want some input before I take it in....
  • helomekhelomek Member Posts: 4
    1999 4.3L 2wd reg cab, short bed

    I have a bad vibration at highway speeds. I already changed shocks, Bilstein, rotated tires. It's bad when I hit the brakes, BUT, I already changed the pads and rotors. Dealer already looked at it once and said everything was "good". Does anyone have any ideas, before I take it in.... Please Help...
  • helomekhelomek Member Posts: 4
  • catamcatam Member Posts: 331
    Has anyone out there had to replace the knock sensor on the 5.3L.
    I talked with a guy I know who stated it is under the intake manifold.
    I am happy to do this job myself, but I am just wondering if anyone out ther has personal experience with removing the intakes on the 5.3, and any helpful hints before I start the job.
  • obyoneobyone Member Posts: 7,841
    Have you changed your tires? I would hope so being that its a '99. Did the vibration begin before or after the current tires were installed?
  • jeffrey3jeffrey3 Member Posts: 2
    my truck knocks when i start it for about 2 minutes everytime

  • obyoneobyone Member Posts: 7,841
    Ever heard of piston slap?
  • helomekhelomek Member Posts: 4
    I have changed my tires. Bridgestone dueler. I would say after, I am not sure.
  • obyoneobyone Member Posts: 7,841
    Seeing that you changed your tires, shocks, pads and rotor, there is one last option if you qualify for it.

    In model years '99 and '00 there is a TSB out for vibrations. It is not well known and only affects 2WD trucks with the rack and pinion. The reason I know about this is that I had my rack changed under warranty with the new rack and no vibration problems. The vibrations usually started around 40-45 and lasted till about 65-70. If this is what you are experiencing, I can post the TSB for you to take to the dealer. Course being out of warranty it will not be free or cheap to do.
  • nelsonsricknelsonsrick Member Posts: 3
    I have the same problem with my 99. Mine does it when I let off the throtle and get back on it. I think it is a transmition problem. Like you, if I step on it, it goes away. What I usually do is manually shift down a gear(automatic tranny) and the shutter goes away. We also tow a large travel trailer with ours. I've just gotten used to down shifting.....the tranny is too expensive to open up.
    Good luck
  • shutterbug3shutterbug3 Member Posts: 4
    Hi nelsonsrick,
    I took the truck to the dealer. I had 1 TOTALLY fouled spark plug and 2 CRACKED plugs!!!! They also replace the wires. That did the trick. A week later, I traded in for a new 2007 3/4 ton Silverado. Have someone check your plugs and wires. I had 69,000 miles at the time.
  • bunnbunn Member Posts: 2
    Been told that GM's answer is that no oil is stored in the filter when engine is shut off. Therefore upon startup oil has to be redistributed and noise stops.
  • obyoneobyone Member Posts: 7,841
    Who at GM told you this?

    It is a bunch of BS. If you ever changed your own oil, you will be able to disprove that theory. The oil filter is full of oil when changing unless GM has found a way to change the laws of physics and gravity.
  • jimseversjimsevers Member Posts: 22
    I agree, this is a BS excuse from a dealer who is trying to give an explanation for a common symptom of these motors. People don't want to hear "it's a common symptom that will not lead to any permanent damage, rather it is an annoyance". This may be true, but nevertheless, it was a design flaw that GM did fix in the next gen V8's. There is no "fix" for it other than to minimize it by using synthetic oil and putting up with it for a minute or less upon cold starts. I have not heard of any cases where this lead to any real mechanical issues or engine failure. Anyone else?
  • obyoneobyone Member Posts: 7,841
    True haven't heard of any engine failures. I would think it would affect resale. From what I've heard its more prevalent on the 6.0.
  • davethecarnutdavethecarnut Member Posts: 248
    Don't use common carb cleaner!!!! Use Mass Air Flow Sensor cleaner by CRC. Spray into sensor and let dry. It dries quick. Don't rub or scrape the sensor
  • davethecarnutdavethecarnut Member Posts: 248
    Clean the MAF sensor first and see if that doesn't do the trick. Also folks, those after market oiled air filters ( k&n, etc) can gunk the MAF sensor, causing problems, if you over oil the filter after cleaning it
  • shutterbug3shutterbug3 Member Posts: 4
  • nelsonsricknelsonsrick Member Posts: 3
    I was just about to tell you to check your plugs!!
    I had a tranny service, and the guy told me it was an ignition problem. So today I did the wires and plugs....problem solved too!!
    I also changed my fuel filter....I have 314,000 km
    thanks anyway
  • aik262aik262 Member Posts: 9
    it,s a blot on bypass tube, for engines that don't have oil cooler option,it just my be loose
  • eyoumanseyoumans Member Posts: 2
    I have a '99 GMC Sierra with 229,000 miles. I want to swap the 4.8ltr. to a 5.3 ltr. Can anyone tell me if all connectors will interchange between these engines? The cable harness look to be the same. How about the computer?
  • chevyman66chevyman66 Member Posts: 2
    iv got a 2000 5.3. cats went bad, and replaced them, throwing codes, like maf sensor, o2 sensors egr, sensors, replaced them all. put new plugs and wires, still wont run right. checked voltages in o2 sensors(11.5-12.5 volts) checked MAF voltage(8.5-9.5) normal? dont know. keeps trowing code 174 = system too lean (bank 2). cant figure out why it will not run. PLEASE help if any body knows whats goin om here. idles ok slow acceleration will rev out, only in neutral, put in gear to drive under a load, the motor falls on its face, seems like starving for fuel. also changed the fuel filter, still nothing. any help is welcome, thanks.
  • lionslions Member Posts: 20
    Ok i have a 2002 5.3v8 ext a cab 4x4 with 42,000 never been hurt or abused just driven lately my truck has been using 2 qts between oil changes every 3000 miles my dealer says this is normal 1 qt per 1500 miles ?? I checked my owners manual and no where does it say this is normal so if any GM techs are reading what do you think also the knock in my engine is getting worse even after the engine is warm. I hope GM is watching Toyota because what i seen of the tundra is wow but i haven't driven it yet. But am a long time GM chevy truck owner but i think 2qts inbetween oil changes is excessive, with the new technolgy and tighter engines they weren't suppose to burn oil. So any help would be great. Thank You Lions
  • 1offroader1offroader Member Posts: 208
    lions - you're right, 2 qts./3,000 mi is too much. I'd say any more than 1 qt./3,000 mi. is excessive. The knocking is worrisome, but may or may not be related to the oil usage. Are you sure the oil is not dripping anywhere? If not, check the compression on all 8 cylinders. That's a point to begin diagnosing both problems.

  • eyoumanseyoumans Member Posts: 2
  • jeffrey3jeffrey3 Member Posts: 2
  • lionslions Member Posts: 20
  • jmj2000jmj2000 Member Posts: 1
  • obyoneobyone Member Posts: 7,841
    Park it in the garage and drive a prius. ;)
  • joryelnjoryeln Member Posts: 2
  • joryelnjoryeln Member Posts: 2

    I have the following,

    5.3L V8

    Oil is allways changes, just changed the
    gas filter, new battery etc..etc.

    When driving fast or with foot on the peddle
    the car is fine. When I drive very slow and
    turn the car will stall and turn off.

    This only happens when Im just about at a stop
    then try and turn in any direction, the car
    turns off. But it starts up just fine everytime.

    Have no idea of what this could be, hopefully
    this has happened to someone else.


  • softysofty Member Posts: 2
  • softysofty Member Posts: 2
    Hi I'm from the UK and we own a 1989 Chevvy Silverado K1500. We recently installed a new distributer pack complete, a water pump and Thermostat all new. Have now replaced noc sensor also, I am having a problem with overheating, the guage reads halfish but the engine boils up, and releases pressure to the overflow. I have just spent 7 1/2 hours flushing through the engine and draining again and again, I have removed noc sensor and flushed engine as well as the radiator and holes. On removal of noc sensor water trickled out until I had a good dig about then loads of water came out, rusty muddy coloured.

    I am hoping this will solve the overheating problem any further ideas......

    My other problem is that the engine seems to be lacking in power, the distributor was installed and set up at top dead centre, should this be advanced, or will this make the overheating worse.

    Any help would be appreciated.
  • cjncjn Member Posts: 2
    1995 Chevy Silverado 2500, 5.7L. White smoke appears at startup goes away a mile or two down the road....When engine is shut off and restarted, the smoke appears again while at startup but engine is still warm. Goes away...mile or two down the road again....
    Anyone have any suggestions as to what this might be?
  • obyoneobyone Member Posts: 7,841
    Still sounds like a blown head gasket.
  • flysprayflyspray Member Posts: 15
    I had a 95 astro van with 4.3L v6.... After I put 165K on the motor... I started to have the same problem. I was told that the valves dont seal properly when the engine is off. This allows oil to drain into the cylinders. When you you crank up it take a short time to burn off the white smoke. I was able to put another 65k on it before it started to loose compression.

  • cjncjn Member Posts: 2
    Thank you very much for all of your replies. I'm just pulling my hair out trying to figure out the issue and hoping it is nothing serious considering it is a professionally rebuilt long block. It just seems like it was a lot of work replacing the engine for nothing, if is, infact the engine. Can't explain all of the moisture pouring from tail pipe. Truck runs good and oil pressure is fine. Thanks
  • dustinpostdustinpost Member Posts: 1
    2000 Silverado 2500, 6.0 vortec.

    When its warm outside and im sitting at a stoplight with the truck in drive the idle fluctuates between 400-700 rpm. I took it to the dealer but he couldn't find any problems. This only happens when its warm/hot outside. It's been happening about 2 years. Also it starts great when its cold outside, but as the day warms up the starting gets harder.

    I have had the fuel injection serviced, new fuel filter. Mechanic says plugs are firing good.

    Any ideas?
  • davethecarnutdavethecarnut Member Posts: 248
    Could be a Mass Air Flow sensor (MAF) problem. Mine was dirty (you can buy cleaner at auto parts store) and caused an idle problem like yours, but the outside temperature wasn't a factor. Anybody else?
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