Misfire or rough idle on the 2008 Chevrolet Silverado 1500
When misfire or rough idle gets reported
Owners of the 2008 Chevrolet Silverado 1500 report misfire or rough idle at a median of 200 miles. A quarter of the reports come in before 100 miles and a quarter after 115,000 miles, from 8 reports that carried an odometer reading.
A part like this is normally expected to survive 92,000 miles. It is the 21st most-reported problem on this model year.
The mileage distribution
The reported range runs from 35 miles at the tenth percentile to 115,000 miles at the ninetieth, a spread of 116,965 miles across the middle 80% of reports.
When the reports scatter this far, the mileage is telling you about how these cars were driven more than about the part itself.
63% of the dated reports were filed under 36,000 miles.
The whole distribution
| 10th | 25th | Median | 75th | 90th |
|---|---|---|---|---|
| 35 miles | 58 miles | 248 miles | 117,000 miles | 117,000 miles |
Read the 10th percentile as “one report in ten arrived this early”. Exact figures are shown in this table because it is the table of record; everywhere else on the site they are rounded to the precision the sample can carry.
What a percentile can and cannot tell you here
These five numbers describe the readings owners gave, in order. The median is the middle one: half the reports arrived below it. The 10th and 90th are the edges of the bulk of the distribution, and the distance between them is the part worth reading. A tight spread — say 70,000 to 95,000 miles — points at something that wears out on a schedule, and the schedule is knowable. A wide one, 20,000 to 190,000, points at a fault that hits some cars and never troubles others, which means the mileage on the listing in front of you tells you very little about your odds.
What these figures are not is a survival curve. Every reading here comes from a car whose owner filed a complaint, so the sample contains only failures: it cannot say what share of the fleet made it past 150,000 miles untouched, because those owners had nothing to report. Nor is the mileage the moment of failure — it is the odometer reading as recalled at the time of filing, which may be weeks later and is sometimes rounded to the nearest ten thousand by the person typing it.
Percentiles are shown at all only once 8 readings exist for the vehicle and mode. Below that the middle of a handful of numbers is noise wearing a decimal point, so the figures are withheld rather than dressed up.
What happens, and what it costs
Putting it right typically runs $250–$1,600 at an independent US shop. That range is an editorial estimate held in this site's failure-mode catalogue, not a figure from NHTSA, and it is a repair cost rather than a diagnosis cost.
The same failure on other years
The same failure is reported on 16 model years of this car. It shows up earliest on the 2008, at a median of 200 miles, and latest on the 2010 at 210,000 miles.
By volume the 2021 carries the most reports, with 53; the 2008 has 8. A mode that appears across most years of a model is usually a design choice rather than a bad batch.
If one year stands out to the left, that is the year to avoid; if the whole line sits at a similar mileage, this is wear rather than a defect in one production run.
Tick median reported mileage Solid middle half of reports Faint 10th to 90th percentile Colour how bad the failure is when it happens
What owners wrote
Verbatim from NHTSA complaint narratives, trimmed for length. The mileage is the one the owner gave.
I purchased a new chevrolet silverado with the vortec max package in september of 2008. Since new, the vehicle has idled rough and surged at stops. It feels like another vehicle has bumped you from behind. I have brought the vehicle in numerous times to be inspected under warranty. General motors came out with a technical service bulletin stating that if the vehicle has a rough idle with no check engine light it is a normal characteristic of the vehicle. The rough idle causes the vehicles RPM's to spike leading to the surge condition. I have asked for the vehicle to be repaired numerous times under the existing warranty and general motors has not taken action stating it is a normal characteristic. There are many other silverado owners with the same problem that do not believe it is a normal characteristic. Any vehicle that feels like it was bumped from behind is a definite safety concern. I am scheduled for an arbitration hearing on july 11, 2011 with the better business bureau and general motors to discuss the problem. The idle/surge problem happens several times per week. My wife has also experienced the problem while driving…
First incident with the engine occurred less than 3 months after purchase. At roughly 88k miles I noticed a skip in power/torque especially when going uphill at a constant speed, a light loss of power was noticed very briefly as if one cylinder was missing. Less than 100 miles later the "service stabilitrak" and check engine lights came on. I had the engine code read and cylinder 7 was misfiring. Took it back to the dealership with 3 days left on my powertrain warranty (thank god right?), wrong. For whatever reason an engine malfunction was not covered under a powertrain warranty. But the leaking and failing brake system was covered. Advised by the dealership the lifters had failed which costed me a grand to fix less than 3 months after purchase. Exactly one year and roughly 20k miles later the truck developed a loud tick right after startup. Its now idling very rough, RPM gauge does not stay consistent at idle and at one point dropped almost to 0, truck almost shut off and then jumped back up. After speaking with an independent mechanic about it he proposed it was the cam from his personal experience. It seems the incorrect…
First incident with the engine occurred less than 3 months after purchase. At roughly 88k miles I noticed a skip in power/torque especially when going uphill at a constant speed, a light loss of power was noticed very briefly as if one cylinder was missing. Less than 100 miles later the "service stabilitrak" and check engine lights came on. I had the engine code read and cylinder 7 was misfiring. Took it back to the dealership with 3 days left on my powertrain warranty (thank god right?), wrong. For whatever reason an engine malfunction was not covered under a powertrain warranty. But the leaking and failing brake system was covered. Advised by the dealership the lifters had failed which costed me a grand to fix less than 3 months after purchase. Exactly one year and roughly 20k miles later the truck developed a loud tick right after startup. Its now idling very rough, RPM gauge does not stay consistent at idle and at one point dropped almost to 0, truck almost shut off and then jumped back up. After speaking with an independent mechanic about it he proposed it was the cam from his personal experience. It seems the incorrect…
Also reported on the 2008 Chevrolet Silverado 1500
Airbag inflator rupture
Other body or interior problem
Other electrical problem
Other engine problem
Airbag warning light or occupant sensor fault
Fuel pump failure
How far this goes
Complaints are voluntary, so 8 is a floor and not a count of affected cars. Mileages are typed in by owners and cluster on round numbers. And the mode itself is assigned by software reading the complaint text, which is reliable in bulk and fallible one report at a time.
Questions this page answers
At what mileage does misfire or rough idle happen on the 2008 Chevrolet Silverado 1500?
Across 8 owner reports that included an odometer reading, half were filed by 200 miles. A quarter were filed before 100 miles and a quarter after 115,000 miles. These are the mileages owners reported when they complained, not a prediction for any individual car.
How common is misfire or rough idle on the 2008 Chevrolet Silverado 1500?
8 reports have been filed with NHTSA, about 0.3 per 1,000 vehicles. Complaints are voluntary, so this is a floor rather than a count of affected cars.
What this is and is not. These are the mileages at which owners chose to complain to a federal agency, which is not the same as the mileage at which the part fails on every car. It skews toward failures that happened outside warranty, cost real money, or frightened someone. It is still the only public dataset that carries failure mileage at all, and the shape of a few hundred readings is informative even when a single one is not. Methodology · JSON · this failure on other cars
Source Owner complaints and recall records published by the US National Highway Traffic Safety Administration, model years 1996–2027 Figures rebuilt Published by AtWhatMileage How every figure is computed