Misfire or rough idle on the 1999 Buick Regal
1 fire 1 of the 3 reports for this failure mention a crash, a fire, an injury or a death. Those are the owner's words on the complaint form, not a verified finding, and one report can mention more than one.
Only 2 reports for this mode came with an odometer reading, which is too few for percentiles to mean anything. The page is here because someone linked to it; treat the figures as anecdotes, and see the full report for this year instead.
When misfire or rough idle gets reported
There are 3 reports of misfire or rough idle on the 1999 Buick Regal, 2 with a mileage attached. That is too few to place the failure on the odometer with any confidence.
A part like this is normally expected to survive 92,000 miles. It is the 20th most-reported problem on this model year.
The whole distribution
| 10th | 25th | Median | 75th | 90th |
|---|---|---|---|---|
| — | — | 69,246 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
Of these reports, 1 a fire is mentioned. Owners write their own complaints and the agency does not verify them, so read this as what the reports say happened rather than as a confirmed count.
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 8 model years of this car. It shows up earliest on the 2015, at a median of 2 miles, and latest on the 1998 at 130,000 miles.
By volume the 2011 carries the most reports, with 12; the 1999 has 3. 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.
[xxx] [xxx] subject: owner complaint my vehicle: 1999 buick regal [xxx] message: on 05/15/04, my car service engine soon indicator came on. The car was running rough and white smoke was coming from the exhaust. I had the car towed to an authorized gm dealer. After $1,226.35 I was told the problem was the upper intake manifold had leaked antifluid into the engine. Upon close inspection, the technician and I notice that the upper intake had corroded badly causing it to leak. The upper intake is made from some kind of black plastic, that layers of it comes off with a slight wipe of my finger. This in my opinion is a design flaw. Now my engine is ruin. The engine service indicator is still on because of internal engine problems caused by the corroded intake manifold. I have only 69,000 miles on the car; therefore this plastic corrosion must have started thousands of miles earlier. I believe general motors (buick) should correct this problem as soon as possible and compensate their customers who have had this design flaw problem. If your engineers wish to inspect the corroded intake manifold, please advise and I will send it to them…
[xxx] [xxx] subject: owner complaint my vehicle: 1999 buick regal [xxx] message: on 05/15/04, my car service engine soon indicator came on. The car was running rough and white smoke was coming from the exhaust. I had the car towed to an authorized gm dealer. After $1,226.35 I was told the problem was the upper intake manifold had leaked antifluid into the engine. Upon close inspection, the technician and I notice that the upper intake had corroded badly causing it to leak. The upper intake is made from some kind of black plastic, that layers of it comes off with a slight wipe of my finger. This in my opinion is a design flaw. Now my engine is ruin. The engine service indicator is still on because of internal engine problems caused by the corroded intake manifold. I have only 69,000 miles on the car; therefore this plastic corrosion must have started thousands of miles earlier. I believe general motors (buick) should correct this problem as soon as possible and compensate their customers who have had this design flaw problem. If your engineers wish to inspect the corroded intake manifold, please advise and I will send it to them…
Also reported on the 1999 Buick Regal
Other engine problem
Other electrical problem
Ignition switch, key fob or immobilizer failure
Steering rack, gear or tie rod failure
Other visibility problem
Other body or interior problem
How far this goes
This page is kept out of search results because 3 reports is not enough to publish percentiles from. It stays reachable because somebody looking at this exact car would rather see the reports than be told there are none.
Complaints are voluntary, so 3 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 1999 Buick Regal?
Across 2 owner reports that included an odometer reading, half were filed by 70,000 miles. A quarter were filed before — and a quarter after —. 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 1999 Buick Regal?
3 reports have been filed with NHTSA, about 0.0 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