Last post on Sep 18, 2013 at 2:32 PM
You are in the Chevrolet Silverado & GMC Sierra
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GMC Sierra 1500, Truck
Jan 17, 2012 (4:14 pm)
I have a 2002 chev with 4.8 litre. In cold weather it idles high and low, also stalls when its really cold. Changed sparkplugs, throttle position sensor, altinator, fuel pump, and still does this. It seems to run better when I unplug the air flow sensor. Just wondering if anyone knows what could be the problem..?
#112 of 151 Re: high, low idle [vantassel]
Jan 18, 2012 (3:45 am)
Try cleaning the MAF wire with some carb cleaner.
Do you get any codes ?
2002 Chevrolet "Truck"?
Theres quite a few TSB on the 1500 pickup, several include running conditions..
check them out, and see if your wrench can identify the issue.
Sometimes it's cheaper to let a "good" dealer to diagnose the problem
2002 Silverado 1500
#113 of 151 Re: high, low idle [drvette]
Jan 18, 2012 (6:16 pm)
you say clean the maf wire with carb cleaner, would that be just the plug in?
the only code that comes up is a misfire on multiple cylinders! yes it is a truck.
#114 of 151 Silverado 2500 HD Cold start issues, bogging down
Jan 29, 2012 (12:12 am)
Ive had this issue for quite some time now. In the mornings after the truck has sat for 8+ hours, I start the truck and the turn over is fine and the engine revs up fine. After the initial start up it begins to bog down, almost as if it is going to die but never does. The RPM's jump back up almost as if you pressed the gas peddal down hard, then idles normal and repeats itself bogging down and back to normal. It has done it a couple times bad enough where it gave me a check engine light but when I leave the driveway it goes away. The only code it throws is a random misfire. After about 10 min, the truck idles fine as if everything is great. No other problems after she warms up. I have checked EVERYTHING (almost)...not a single mechanic can figure out why it is doing this. I have had new plugs, new fuel filter, mass airflow sensor, IAC valve, etc. I have a buddy with one of those code readers and he says everything shows my truck is running fine. he told me to try unplugging my MAF sensor and see what it did, crazy this is....it seemed to make the bogging go away...so I thought that was the problem...NOPE! Can someone PLEASE tell me what this "COULD" be or what could be causing this??? Anything will be helpful! Thanks!
#115 of 151 Re: Silverado 2500 HD Cold start issues, bogging down [5150chevyman]
Jan 29, 2012 (8:30 am)
Was the MAF oem or aftermarket?
Check the throttle position sensor?
#116 of 151 Re: high, low idle [vantassel]
Feb 17, 2012 (9:51 pm)
I have a 2002 GMC Sierra 1500 that had the exact same symptoms.I was told by a friend that also had the same problem with his 2002 that it was the intake manifold gaskets leaking ( vacuum leak). I live in Alaska and we get some pretty severe temperature swings (it was -40F 3 weeks ago,now it's +20F). I think the composite manifold shrinks slightly in the cold which exaggerates the leak. I replaced the gaskets with new GM factory gaskets and it worked. Runs like a champ now. I read somewhere that the original gaskets on the 2002 used a inferior compound for the rubber seal, which GM has changed. The old rubber on the gaskets was orange, the new gaskets I purchased from GM had a teal colored rubber gasket.
#117 of 151 Sluggish sometimes
Mar 07, 2012 (3:31 pm)
I have a 2002 Chevy Silverado z71. When I first get up in the morning the truck runs fine (it is a little sluggish). When I leave work it runs horribly. When I step on the accelerator it bogs down and when I let up on the pedal just a little it will accelerate just fine for a bit then bog down and start shaking. I jsut replaced my catalytic convertor less than 20,000 miles ago. I have replaced fuel filter, spark plugs and wires. Any help would be great.
#118 of 151 Re: Sluggish sometimes [aceeric22]
Mar 10, 2012 (2:01 am)
I'd start by cleaning the throtte body and checking the throttle position sensor.
#119 of 151 Re: Silverado 2500 HD Cold start issues, bogging down [5150chevyman]
Apr 26, 2012 (2:08 pm)
OK, THE PROBLEM WE FOUND IS SOMETHING PROGRAMED INTO THE COMPUTER TO MAKE IT PUT OUT A 300 CODE AFTER HIGH MILES TO MAKE US
1- TURN IT IN & BUY AN OTHER ONE, BEFORE SOME THING GOES BAD.
2- SPEND A LOT OF MONEY AT THE DEALER TO TRY TO FIND THE PROBLEM .
3- JUST TO DRIVE US NUTS THINKING WE HAVE A BIG PROBLEM.
OUR TRUCK RUNS FINE ACCEPT FOR THAT CODE, THEREFORE WE DO NOT CARE HOW MANY TIMES IT FLASHES.
I SAY ENJOY YOUR TRUCK FORGET THE CODE 300.!!!!!!!!!!
SAINTLEN, MACH. FOR OVER 50 YEARS.
#120 of 151 GMC Sierra 2012 engine problem
Jul 26, 2012 (1:41 am)
about 3 months ago I bought a GMC sierra 2012 V6 4.3L from the showroom brand new.
Last month it went for its first 10 000km service, but from around 5000km on the car I have had a problem with my car not wanting to pull away, for example when I am at a roundabout and i need to press the accelerator to go forward, the car does not move, it goes forward really slowly and then makes a loud bang noise from the right front side of the engine, only after this sound comes the car has its normal speed back and moves.
Though this problem only happens sometimes. somedays this does not happen and other days it does it 3 for times.. I have been to the Main GMC service centre several times and the assistant manager even took it for a test drive but this problem did not happen with him in the car. now he is accusing me of lying.
Does anyone have this problem or know what it might be, it will be a great help.
ps. my car has been more in the service center than i have actually driven it.. :'(