Chevy Silverado and GMC Sierra Gasoline Engine Problems

swiederinswiederin Member Posts: 1
I have a 99 Silverado w/5.3L engine. The idle speed is too low. It gets as low as 430 rpm when I firsty put the tranny in drive and then the idle increases to a more acceptable level. There are no DTC's. This problem is most noticeable when you pull up to a stop. The engine rpm's get low enough to dim the lights and almoist stall the engine. The engine has 62k miles.


  • chrisarachrisara Member Posts: 2
    I am have the same exact problem with my 2003 4.3. Did you find a solution to the problem? If so please email me.
  • fatboyntroyfatboyntroy Member Posts: 3
    Ditto fellas, I just bought an 01 silverado 5.3L w/ 66,000 miles, and the idle adjustment is too low. I don't know what it should be,(my tach reads 200-400 w/AC on), but i know it shouldn't almost choke down at every stop (as well as the headlights dimming.)The thing is, its not a rough idle, it runs very smooth but just so low that it almost chokes, and surges when given gas.Some have suggested a vacuum leak, faulty ground, or ECM problems. Still looking for answers. All advice is greatly appreciated. Thanks
  • muddingmudding Member Posts: 3
    I have a 2003 Sierra 2500 4x4. After the truck sets for about 20 minutes you hear a very loud "pop". The dealership has replaced the heat shield and that didn't fix the "popping". Any ideas???? Please........
  • obyoneobyone Member Posts: 7,841
    It's probably the exhaust contracting on cool down.
  • muddingmudding Member Posts: 3
  • muddingmudding Member Posts: 3
    It's much louder than the normal cooling down noises. It's a loud "pop" or "ping".
  • fatboyntroyfatboyntroy Member Posts: 3
    Hey guys, problem solved!!! A friend recommended I call his mechanic, and he told me the low idle was a common problem on these engines. Actually, the real problem is that the accelerator is sticking (although this is not as evident as the low idle; this is why you feel the surge, instead of a smooth acceleration. The low idle is a by-product of this problem). The problem is due to hydrocarbon (sludge) buildup inside the throttle body, and possibly the air flow sensor. He cleaned both (I assume with something like common carb cleaner?). Anyway, she runs like a charm now! I was amazed at the smooth transition of the tranny!!! This was because the accelerator was sticking & had nothing to do with the tranny. The tach has gone from 300-400 in gear w/ac compressor on (almost choking at stops) to an even 500 & idling perfectly. Just want to emphasize that you may not feel the accelerator sticking, but if you experience low idle, you may be surprised at the difference when you do this! He charged me $40 to do this but said the problem may recur in 25,000 miles & may need cleaning again. However, I believe these cleaning procedures may be covered in a Chilton's or Haynes manual. Hope this helps & good luck guys
  • gmharrisongmharrison Member Posts: 2
  • gmharrisongmharrison Member Posts: 2
    I have a 2001 chev silverado with the 4.3L v6 it seems that any time the tranny shifts up and the rpm's drop to around 1000 I get a labouring sound from the engine a the whole truck vibrates. If you increase the rpms to say 1200 it goes away. Any ideas? It does it at all speeds but only when the rpms are around 1000
  • assclownassclown Member Posts: 2
    I want to replace my 195 degree thermostat with a 180 degree one for my 2006 GMC Sierra with the 4.8 litre engine. Anybody know where to purchase one or know of one from a different model that will fit?
  • assclownassclown Member Posts: 2
  • sanchezgggsanchezggg Member Posts: 2
  • sanchezgggsanchezggg Member Posts: 2
    Having problems with my 2001 silverado 2wd. it rotates over and idles until it shuts off. I just changed spark plugs and they smelled like fuel. It ran for a bit longer with the new spark plugs but then died down.I was thinking about changing the fuel filter and cleaning the throttle body for build up. i was thinking of fuel system because it had been sitting the last 7-8 months because i just got out the military.
  • foxlawnfoxlawn Member Posts: 2
  • foxlawnfoxlawn Member Posts: 2
    I have a 2002 silverado 2500hd auto,6.0 engine 100,000 miles, there is a intermitten miss or skip in the engine under load 30-65 mph, no codes on scan, o2 sensors replaced,fuel tank cleaned & fuelpump replaced, fuel filter replaced, plugs & wires replaced, engine serviced, trans serviced , computer reprogramed by dealer, still got the miss sometimes its not so noticeable sometimes its more of a jurking, please someone help I love this truck
  • h20explorerh20explorer Member Posts: 3
    1999 Silverado 2500 6.0 L motor. In the morning or after sitting for a short while the oil pressure does not rise to a sufficient pressure to prevent the lifters from rattling until the pressure gets to approx. 20psi. Any thought

  • h20explorerh20explorer Member Posts: 3
    What brand of fuel have you used during it's life. Have you had the injectors cleaned recently. It my be concidered a soft miss from one or more partially restricted injectors.
    It's my understanding the computor is not scheduled to record and error until it misses more them 250 times.
    I had spark plug wires go bad and the computor didn't record a fault. I finally had to have the service technition go for a test ride with the computor attached and have him watch it very carefully to even see the miss.
    Best of luck
  • tbullingtontbullington Member Posts: 5
    Since I bought the truck used in '03 it often will not turn over and crank. Sometimes it starts as soon as I turn the key, but often I have to pat the accelerator and hold the key. I have checked the fuel pump, and it checks out. Someone told me that it might be the fuel pressure regulator, and others have said to replace the fuel filter. I have no problems once the truck is cranked and running, but as soon as I turn it off and try to start it again it may not crank. Please help
  • obmobm Member Posts: 2
    I have a 2001 3500 with an 8.1L engine with the check engine light on. It scans code 342 for cam position sensor low voltage. Replaced the cam position sensor with a new GM unit. Cleared the code. The light comes back on after about 30 miles driving. Same code.

    Is there more than one cam position sensor on this engine or does anyone have any suggestions on why I'm getting the low voltage reading? The engine runs great. Do you think it will leave me by the side of the road?

    Thanks for any advise anyone can give me.
  • edboggsedboggs Member Posts: 3
    This isn't the right place to ask these questions. Havn't you guys ever heard of Someone needs to ask mommy if he can go outside once in a while.
  • KCRamKCRam Member Posts: 3,516
    Why not make this the place? :)

    kcram - Pickups Host
  • obmobm Member Posts: 2
    No I've never heard of That's why I asked for help. Didn't need help with my Fords.
    I'm not going to complain about GMC, they gave me 2 torque converters 1 Reman. tranny 1 brand new 2004 tranny with 100K warranty, new front hubs, brake pads and rotors all the way around. Rented me a car that we had for 3 weeks and towed my truck several times for several hundred miles.
    Anyway the cam sensor for the 2001 is different than the generic 2002 and newer uses that the Chevy dealer said was the replacement. Got a 2001 specific sensor from Standard [after market] and all's well for about 3 weeks and 1000 miles.
    P.S. Someones mommy should tell junior to take his nap and put the computer away..
  • 03chevy03chevy Member Posts: 5
    I have the same problem with my 2003 4.8 silverado. but it only does it when i reset the computer or mess with the program. it will idle low and and sometimes die when i stop or turn hard. Now here's the kicker after a week or so it will gradually get better until it idles just fine. that is in till the next time i re program something on the computer. And i never get any dtc's. Is there anyone else out there with this problem or maybe a solution?
  • tcush1tcush1 Member Posts: 1
    I have a 2001 that is having the same problem. Today it won't even turn over. I had just a couple of "no engine turn" in the past year but today it won't react at all. I'm guessing it's either the anti-theft or a relay. It would still turn over if it was the fuel pump, just not start. Did you have any luck?????
  • trav907trav907 Member Posts: 1
    I have a 2003 Silverado SS with 6.0. Will turn over but getting no spark. Haven't ran computer diagnostic on it yet, but i'm pretty depressed my truck won't start. Maybe I have similiar problem??
  • 03chevy03chevy Member Posts: 5
    don't know whats wrong with your truck but i am curious let me kn ow whats up when you get it fixed
  • gbrewergbrewer Member Posts: 7
    Not sure if its the problem, check your crank sensor. Had a Jeep and it goes out on it about twice a year. Cost $31.00 for the jeep sensor.
  • growcotton0growcotton0 Member Posts: 1
    When let off of accelerator at any speed but especially above 50mph, there is slack between the engine and rear end/trans and or both. Truck has 140,000 miles, u-joints have been checked.
  • rookie8rookie8 Member Posts: 1
    My 2003 GMC Sierra 2500HD with the 6.0 liter has a MAF code according to the service tech working on it. He however has test the MAF sensor and believes it to be working properly. After some additional testing he is now telling me that the code and the rough idle are caused by a leaking intake manifold gasket. Is this possible?
    Please help.
  • smatsusmatsu Member Posts: 2
    I have an 01 Silverado and it takes two turns to start up when cold, then when it does there is a tapping noise util it warms up. Is it a valve or lifter problem?
  • obyoneobyone Member Posts: 7,841
    It is a piston problem.
  • ahoronahoron Member Posts: 30
    The noise is most likely what gm calls "piston slap" GM has a tsb about it. The fix is to do nothing they say it has no effect on engine life. My truck only does it if it is cold out. The full size trucks starting in 1999 have this problem.
  • rgray1rgray1 Member Posts: 2
    Please help, I am having a rough idle problem on my 1989 K1500 Silverado. One morning I started my truck which starts fine by the way, and I noticed while giving it gas it started to produce a rough idle and has been with it ever since. While the truck is idleing you can hear and feel the roughness, while driving you can feel the miss but there is no backfiring or anything like that. I recently changed plugs, wires, cap, and rotor, and that still didnt cure problem. Checked the codes pulled up faulty EGR changed the EGR valve as well as the EGR solenoid, still did not cure the problem. Checked timing and that is ok. I dont know where to look from here. I really dont want to take it to a shop to have them pull no codes and tell me they cant find the problem and charge me 500.00 dollars. I am trying to see if I cant determine the problem first.
  • rgray1rgray1 Member Posts: 2
  • stevewhitstevewhit Member Posts: 4
    I have the same truck. '89 was a good year. Mine had a failed gasket under the throttle body. It was half gone. I guess it got sucked into the engine. Replaced it and the idle and smooth running came back. Did this at about 150k mi. now 202k. Gasket was about $3.oo at Autozone.
    Cheers :)
  • smatsusmatsu Member Posts: 2
  • obyoneobyone Member Posts: 7,841
    GM kept the pistons slapping since ' that's consistent
  • shutterbug3shutterbug3 Member Posts: 4
    Good evening, I just started to have a problem with my '01 Silverado, 6.0L V8, 2500, 4.10 rear. When I start out up a hill from a dead stop, the engine goes through its gears while accelerating normally.

    But, when the speed levels out at 45-50 mph and the tach shows a drop to a lower gear (while still going uphill) the truck feels like it's jerking. As soon as I give it a little gas to get out of that gear, it goes away. Also, if I stomp on the gas to get into passing gear, it goes away.

    A friend says two other chevy's he knows of had this same problem and it was the fuel filter under the driver's side of the truck. While I hope this is all it is, I also hope it is NOT a transmission problem, as I tow a 27' 5th wheel. Any suggestions?? Thank you very much.
  • shutterbug3shutterbug3 Member Posts: 4
    Hello everyone,
    I forgot to add the fact that when the speed is between 45-50 mph, the tach is at 1500rpm. This is when it starts to jerk.
  • twidgettwidget Member Posts: 1
    We are experiencing the same problem on our 2001 Silverado. We took it to the auto shop and they said the injectors were bad due to sludge and had to be replaced. They replaced them but it did not fix anything. We had already changed the fuel filter, spark plugs ect. What did you find out about your truck?
  • mailman2mailman2 Member Posts: 15
    How hard is it to replace the 2 drive belts on the 5.3? Any help on the procedure, like taking the shroud off or what size wrench or anything else I should know? Thanks
  • mailman2mailman2 Member Posts: 15
  • chevy123chevy123 Member Posts: 1
    This is getting to be a common problem with the 5.3L and 6.0L GM engines. I went to Auto Zone to check my engine light, they said MAF sensor. I replaced it, but no change. Auto Zone agreed to let me return the MAF sensor (very nice folks down there) and I was on my way to the dealer. Dealer ran diagnostics check, and found intake gasket to be leaking. ~$350 to replace on 5.3L. Don't waste your money trying a bunch of parts, go right to a Chevy dealer's service department to fix it right the first time.
  • gholdegholde Member Posts: 4
    2000 GMC Silverado extcb 4x4 5.3l 120,000km

    I have had a major (super loud) howl/squeal coming from the belt area of my truck. It happens at idle and varies with throttle position. It used to only happen when it was cold back in November and then go away as the truck warmed up but now it is persistent every time I start it and doesn't go away. I don't know if it is "cold" dependent or if the problem has just finally come to a head as we haven't had a day over -10 for quite sometime for me to check to see if the sound goes away once it warms up.

    Attempted fixes:
    I started it one cold morning and let it howl. I oulled off the splash gaurd and proceded to hit all the pulley bearings I could see with kroil to see if I could find the problem bearing or pulley. No dice, it didnt stop.

    Its impossible to tell where the sound is coming from with the naked ear with all the noise of a running motor. I havent taken the belt off and run the truck for a bit to see if if that stops the noise.

    Side note:
    The alternator went south on me about a month ago so I replaced it and the battery and belt. I figured I might as well when I was under the hood anyways. All is well with the charging system now, so I think this should eliminate the alternator and the belt from the equation.

    Any ideas???

    I'm going to get a mechanics stethoscope and try to pinpoint the problem. What should I be listening for and where should I be listening with the probe of the stethoscope????

    Waterpump/pulletys/AC pulleys etc...???
  • hottrucks4uhottrucks4u Member Posts: 1
    We have the same issue. We have a 2001 Silverado that started "not starting" right after we bought it brand new from the dealer. Will do it every once in a while, today it did it when I tried to go to work and then when I tried to Leave work at the end of the day. That was a first. Two times in one day. Have you had any luck figuring out what the problem is? I have taken it to the dealer and they can't find anything wrong with it? Frustrated and looking at buying a Ram.
  • markw8markw8 Member Posts: 25
    My 2000 siverado 2500 would crank at times and not start. The dealer changed the ign. switch,I think. It had something to do with the security light. mark.
  • dakelloggdakellogg Member Posts: 2
  • dakelloggdakellogg Member Posts: 2
    we have a 99 gmc sierra 1500 and we have been told that the oil leaking from the area of the rear main seal may not be that at all. they said it maybe the the part above the oil filter that has 2 o-rings that maybe worn. has anybody heard of this. please help out because that would be better for us money wise.
  • don68don68 Member Posts: 2
    I am having a problem starting my 2000 chevy silverado it starts fine when it is cold but I seem to have a harder time getting it to start after it has set for a couple of does start but it takes a few seconds with the key turned over I have already replaced the fuel filter,spark plugs, and cleaned the throttle body and dont know what else it could be?any help would be appreciated thanks don.
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