Radiator or coolant leak on the 2018 GMC Sierra 1500
1 crash 1 injury 2 of the 11 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 7 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 radiator or coolant leak gets reported
There are 11 reports of radiator or coolant leak on the 2018 GMC Sierra 1500, 7 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 98,000 miles. It is the 7th most-reported problem on this model year.
The whole distribution
| 10th | 25th | Median | 75th | 90th |
|---|---|---|---|---|
| — | — | 58,500 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 crash and 1 an injury are 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 $350–$1,900 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 6 model years of this car. It shows up earliest on the 2014, at a median of 50,000 miles, and latest on the 2021 at 120,000 miles.
By volume the 2014 carries the most reports, with 22; the 2018 has 11. 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.
Struck a deer with the vehicle at approx. 75mph. The driver side airbag deployed. Control of the vehicle was maintained and there was no sudden deceleration. The cover of the steering wheel, which bears a plastic gmc logo that is heavier than the rest of the material blew exactly on the corner of the g. Due to the location of the split the logo hit my wrist like a hammer causing nerve damage and permanently stamping the gmc logo on my wrist. I currently possess all deployed SRS components along with the acm that was in the vehicle at the time of deployment. The damage, aside from the SRS components, was only to the bumper, grill, and condenser with minor damage to the core support where the bumper mounts (radiator, fenders, and hood were not impacted). I question the safety of the way the steering wheel split as the edge of the g has a sharp edge that could have potentially slit my wrist open. I also question the deployment of the bag due to no sudden deceleration and that if the bag had not been deployed there would have been no injury in this loss. Also I had previously had an issue where I started the vehicle on the first cold…
Also reported on the 2018 GMC Sierra 1500
Other powertrain problem
Other brake problem
Other electrical problem
Other engine problem
Other steering problem
Lifter, cam or cylinder-deactivation failure
How far this goes
This page is kept out of search results because 11 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 11 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 radiator or coolant leak happen on the 2018 GMC Sierra 1500?
Across 7 owner reports that included an odometer reading, half were filed by 60,000 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 radiator or coolant leak on the 2018 GMC Sierra 1500?
11 reports have been filed with NHTSA, about 0.1 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