2004 120,000 miles, will surge

Asked by Oct 20, 2012 at 03:00 PM about the 2004 Chevrolet Silverado 1500 Work Truck Ext Cab Short Bed 2WD

Question type: Maintenance & Repair

When I first start the truck it runs good but then it will surge, run good then surge again. Thought at first it was the transmission but thats not it.  Not sure if there is some sensor going bad or not. No engine light comes on.  Seems ok once the truck gets warmed out.

9 Answers


While driving or at an idle?

2 of 2 people found this helpful.

While driving


Could be a number of things, when was it last tuned up?

1 of 1 people found this helpful.

Well, I changed plugs and wires at 100,000 along with cleaning out the injectors. It does seem to run rough when I first start up then it settles down. Thanks


How long does it run like this, is it seconds or minutes. Also did you put the iridium plugs in it or the cheap ones. The newer General Motors ignition systems use an HEI ignition system for a cleaner burn. They used to have HEI on the distributor systems in the late 80s also and the reason those were marked HEI and the new ones aren't is because all the new GMs have it. Point is that instead of 30,000 Volts the new ones are 60,000 to 90,000 Volts and standard plugs are lucky to make it 30,000 miles some crap out as quick as 10,000. It may be starting to need decent plugs and the bad ones just aren't creating the spark needed while the engine is cold and in open loop mode. Let me know what plugs were used and we can go from there.

1 of 1 people found this helpful.

John, I'll have to get back with on that. I looked at my idemized bill and it doesn't specify. I know the plugs cost me $48.00. I'll have to pop the hood and check but I have the feeling I may have got the cheaper ones. Thanks for all your help.


What is the spark plug part number on that itemized bill? It should start with a 41-*** if it starts with an R then its just a standard copper plug. Also the plugs alone are approximately $7 which for the 4.8 or 5.3 is 8 plugs. So the plugs alone would be $56 + tax. A shop would be closer to $100 for the same plugs. If they aren't AC Delco then its the wrong brand all together.

1 of 1 people found this helpful.

Thanks, I'll check the numbers tomorrow. Silly question but will the bad plugs make the truck hard to start?


Crappy plugs can make it start hard and run crappy while its colder due to the fact that while its cold #1 the air is denser making it thicker and more difficult to pass a good spark through it and #2 when an engine is cold its in what's called open loop mode where most sensors do very little and the rest do nothing. A predetermined amount of fuel is put into the engine depending on where the throttle position sensor reading is and the mas air flow sensor is not payed any attention. This also why your vehicle sometimes smells like gas when its started on a cold and damp morning.

1 of 1 people found this helpful.

Your Answer

Silverado 1500

Looking for a Used Silverado 1500 in your area?

CarGurus has 162,529 nationwide Silverado 1500 listings starting at $1,500.


Chevrolet Silverado 1500 Experts

  • #1
    John Carson
  • #2
  • #3
    Andrew Olsen
View All

Related Models For Sale

Used GMC Sierra 1500
1,232 Great Deals out of 62,804 listings starting at $1,995
Used Ford F-150
3,178 Great Deals out of 223,015 listings starting at $1,000
Used Chevrolet Silverado 2500HD
413 Great Deals out of 29,430 listings starting at $2,000
Used Dodge Ram 1500
369 Great Deals out of 10,983 listings starting at $1,800
Used Toyota Tundra
680 Great Deals out of 34,072 listings starting at $1,500
Used Toyota Tacoma
658 Great Deals out of 41,138 listings starting at $2,500
Used Chevrolet Tahoe
849 Great Deals out of 39,759 listings starting at $1,990
Used Chevrolet Colorado
408 Great Deals out of 38,446 listings starting at $1,995
Used Ford F-250 Super Duty
475 Great Deals out of 46,555 listings starting at $595
Used GMC Sierra 2500HD
102 Great Deals out of 13,565 listings starting at $1,950
Used Chevrolet Silverado 2500
6 Great Deals out of 248 listings starting at $3,995
Used Nissan Titan
309 Great Deals out of 18,796 listings starting at $3,298
Used Chevrolet Avalanche
212 Great Deals out of 5,036 listings starting at $2,000

Used Cars For Sale

2018 Chevrolet Silverado 1500 For Sale
18 Great Deals out of 82,961 listings starting at $18,945
2017 Chevrolet Silverado 1500 For Sale
241 Great Deals out of 17,603 listings starting at $17,999
2016 Chevrolet Silverado 1500 For Sale
288 Great Deals out of 7,175 listings starting at $14,495
2015 Chevrolet Silverado 1500 For Sale
492 Great Deals out of 12,023 listings starting at $10,995
2014 Chevrolet Silverado 1500 For Sale
537 Great Deals out of 11,875 listings starting at $9,500

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.