Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Chevy Silverado and GMC Sierra Gasoline Engine Problems



  • crown3crown3 Posts: 1
    220,000 miles, engine light is on and I've been told by few friends that it's likley the Oxygen Sensor, I've read several posts and notices that there may be more then one sensor.
    #1 Where can I find detailed instructions with diagrams hopefully, how to place one or more of these sensors, if I'm able to determine through the local parts store which on it is?
    #2 Is this a job that a basic do it yourself person can do?

    Thank you
  • I was given a 2001 chevy silverado 2500 6.0l vortec. Its has 297,500 miles on it and runs very good, but however i have this tapping noise like everyone else have. But in my case, its at the start, during, and finish of my trip driving. My question is, "Will a 20/50 oil help or what would someone with experience suggest?" Thank-you in advance for any help.
  • I would try those high mileage oil's constantly ticking when the engine is running? Maybe oil isn't getting up to the valvetrain.....
  • obyoneobyone Posts: 8,054
    There are 4 sensors. One before and after the catalytic converters. Since you're at 220K miles, I'd recommend changing all 4.

    It's easy to do but you need to buy a special socket.
  • Thanks Dave, Ill try them additives....the oil pressure gauge is bouncing back and forth between 30 and 60 while i drive and it will literally go to zero (0) if i stay in idle/park and the message light will say check oil pressure and the truck will cut off. Think the oil pump is bad? Thanks.
  • On the Chevy Silv., 2001 - 6.0l vortec, w/ 298k miles...the oil pressure gauge is bouncing back and forth between 30 and 60 while i drive and it will literally go to zero (0) if i stay in idle/park and the message light will say check oil pressure and the truck will cut off. Think the oil pump is bad; going bad; the lifter/s or valve/s is tapping sorta loud? Thanks in advance for any advice. Kevin
  • Did you find out what caused this? Mine will start up and act like it is flooding or running rich, backfiring under the hood and have no power for about 1 or 2 minutes and then it is fine. It doesn't usually do it in the morning, but when I come out after work, it does it almost every time.
  • I have a 6.2 Flex fuel 09 403HP. My question is does anyone know how the roller lifters are oiled in my engine?
    In the old days of hydraulic and solid lifters splash seemed to work in non Hi-Perf. motors. I have read on some forums that roller lifters and roller rockers need lube. It is said,in low rpm range, MODERN ENGINES do not splash as much oil as older motors and the needle bearings of modern motors need oiling at low RPM's (2000 to 3000RPMs) or might have wear and breakage issues.
    Does any one in this community know of or heard any or some or just a few 6.2 L 403 HP V8's having roller issues? Does anyone know specificly,does the 6.2 have mist,pressure or non needle bearing rollers?
    I run syn. oil and will be running Oil analysis so I assume I would know if the needle bearing are wearing it would show even though I am running a bypass system that has a 2 micron absolute filtering.
    Ideas and opinions would be appreciated.
  • Hello, first of all I'd like to say that I have scoured these forums for a solution to my problem and haven't found anything that could help. I am a quadriplegic and I don't drive but I am writing this to help my son who has a 1997 GMC Sierra 1500 with a 5.7 L vortec engine with 180,000 miles on it. The truck starts and runs fine until it warms up. After that, you can get the RPM up if you slowly work the accelerator but as soon step on it, the engine just bogs down until you back off the accelerator. It almost seems like it ran out of gas. He has replaced the fuel pump, fuel filter, the ignition module. It's not throwing any codes. Needless to say this is very frustrating and the truck is basically useless under these conditions. He isn't a mechanic and is unemployed at the moment so he just can't start throwing money at it. Any help that I can get here on this forum would be greatly appreciated. Thank you, Paul
  • wmazwmaz Posts: 3
    My 2000 Silverado has a P0300 code. I have done all of the stuff I have read about on the internet. New fuel filter, cleaned injectors, new plugs, checked for vacuum leaks, etc, etc. I finally gave up and took the truck to a mechanic. He found misfire history on cyl 1 & 6. Strangely they have the exact same misfire count. I took the #6 injector and swapped with #2. Drove the truck and went back. The same counts again on the same cylinders. Why 1 and 6? Why the same count? He now wants to check wiring since 1 and 6 fuel injector pins are next to each other on the PCM. There aren't any misfires at idle. Only at highway speed. I'm thinking the PCM is corrupt and should be flashed. Any other thoughts from you guys? Thanks
  • I have a similar problem. My 1999 GMC K1500 5.7L Suburban also bogs down when the accelerated is pressed. It will typically run fine for a while then it starts this. I find that it is easier to drive without the cruise control when this is happening because I can feather the accelerator to speedup slowly whereas the cruise control will try to accelerate more quickly which causes it to start missing/bucking then eventually the cruise will drop out. If I press the accelerator hard, it simply bogs down as 'themajickman' described. I have also found that turning the engine off then back on clears the problem for a few more miles. I have replaced the fuel filter and O2 sensors and I have also put a lot of fuel system cleaner through the system. The problem went away for several months but came back yesterday. I suspected the fuel system but turning it off for a few seconds should not be long enough to let the fuel pressure drop in case it is caused by trash. The engine light has only come on twice even this condition has existed for a long time, and the code did not give a good indication of the problem. The problem is not directly related to speed. One thing that may be unrelated is that if I put it in neutral and shut off the engine while driving (with a straight clear road, of course), it takes the speedometer 5 to 6 seconds to drop to zero. It continues to operate even though the key is off. Could this indicate a buildup of charge somewhere in the electrical system that could be causing the problem. Just a shot in the dark!
  • obyoneobyone Posts: 8,054
    Sounds like a bad throttle position sensor
  • 1999 chevy pickup 5.3 engine gettin codes of po171 and po 174 wonderin what they stand for
  • obyoneobyone Posts: 8,054
    P0171 System too lean (Bank 1) O2 sensor detected a lean condition on bank 1 which is the same side as cylinder 1

    P0174 System too lean (Bank 2) lean condition on side opposite bank 1
  • I replaced the throttle position sensor and at first it seemed like it might be better but on the road, the problem returned. Light came on so read the code again and it said the same thing as before, i.e. the O2 sensors, which I had already replaced. I then cleaned the mass air flow sensor with no improvement. I then replaced the MAF sensor and again, it seemed to run better at first but then the problem returned. To recoup the problem, it gets to where it will only accelerate very slowly. It won't even accelerate as much as the cruise wants to in order to maintain highway speeds on a slight hill. it stutters badly but when the accelerator is pressed hard, it does not stutter, but it also does not accelerate.

    I ran another test. On the road, without being able to accelerate beyond just feathering the accelerator to accelerate very slowly, I floored it and the engine speed did not change significantly, didn't go up or down. Thought that maybe it didn't go down because of the transmission still being in gear so I shifted to neutral. The engine still held at the same RPM, even though it was in neutral (no load) and the accelerator was floored.

    Here's what has been replaced.
    - O2 (all four)
    - TPS
    - MAF
    - Air filter
  • We have 1994 chev 1500 truck was doing the same type of thing - would start to cough and sputter and seem as though it was going to quit running but never actually did. We would have to slow down considerably and found that if we shut it off and let sit for 5 or 10 minutes it would be fine for a while and then it would start again. We went through all sorts of things like map sensor, o2 sensor etc - someone suggested that the distributor is a problem on these vehicles, had it changed and the problem is solved at last.
  • We were driving and all of a sudden we heard thisloud bang and all the alert lights went on. We pulled over & turned the engine off, but it would not restart and all of the gages went dead. We towed it home & it did not have any power and the window, which is electric, would no longer go up or down. What would have snapped to cause so many issues to occur at once?
  • Hi I have a 99 GMC Sierra 1500 Z71 4x4 new body with a 5.3.I was told that 99 only will fit my truck,dose any one know if any other gmc year will fit?or chevy.
    I really need the help,the dealer's here in Vermont are no help.
    George :sick:
  • obyoneobyone Posts: 8,054
    What is it that you're trying to fit?
  • I'm sorry it need a new motor and every one's saying 99 only will fit,
  • obyoneobyone Posts: 8,054
    The manual shows that either a 1999 or a 2000 should work for your truck.
  • my brothers 91 siverado 2500 with a v8 and auto. trans. tachs out after warming up. the truck starts off slow and slowly picks up speed. it slowly shifts after the rpms have been high for a while. the tranny fluid is full.
  • i have a chevy silverado 1500 5.3 and the waterpump went out. replace it and now when i drive a constant speed then let off the gas when i give it gas again it stutters realy bad. when the waterpump went out it did overheat. any advise?
  • This truck, 07 gmc 2500 hd 6.0 litre gas.. has a throttle/run problem at cold start take offs, when I hit the gas, it just falls on it's face and I have to let completely off the throttle and just ease back into it untill it's rollin pretty good.. when operating temp comes up it's all ok. Anybody know about or had this same problem? Thanks for any help
Sign In or Register to comment.