Radiator or coolant leak on the 1998 Buick Lesabre
When radiator or coolant leak gets reported
Owners of the 1998 Buick Lesabre report radiator or coolant leak at a median of 60,000 miles. A quarter of the reports come in before 45,000 miles and a quarter after 65,000 miles, from 17 reports that carried an odometer reading.
A part like this is normally expected to survive 98,000 miles. It is the 5th most-reported problem on this model year.
The mileage distribution
The reported range runs from 25,000 miles at the tenth percentile to 80,000 miles at the ninetieth, a spread of 54,090 miles across the middle 80% of reports.
A window that narrow is the signature of a part that fails on its own schedule rather than on how the car is driven — which is usually a design or supplier problem rather than wear and tear.
18% of the dated reports were filed under 36,000 miles.
The whole distribution
| 10th | 25th | Median | 75th | 90th |
|---|---|---|---|---|
| 26,000 miles | 43,000 miles | 58,000 miles | 62,750 miles | 80,090 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 $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 5 model years of this car. It shows up earliest on the 2001, at a median of 55,000 miles, and latest on the 2000 at 135,000 miles.
By volume the 1998 is the worst of them, which makes this a problem of this specific year rather than of the model as a whole.
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.
While returning home from our daughter's in virginia, our check engine light came on. We pulled onto a side road and turned off the car. Looking under the hood, we found the reserve radiator reservoir to be totally empty. After 20 minutes, we tried to start the car to no avail. We were towed back to the nearest town, selinsgrove, pa, to a pep boys and were told the engine had seized up. The next day the car was towed back to rochester where our mechanic proceeded to find out the problem. We also called the dealership where we bought the car two years ago, and the service manager told us that he had seen this before. The radiator fluid is entirely sucked into the engine through the intake manifold and there is never any indication of over heating or changes on the gauge readings because the engine is not hot, due to the fluid being in there. Consequently, we had to have the engine replaced. Three days after this happened to us, a letter was mailed out to all owners of 2000-2003 buicks for this very same problem. We have a 1998 buick lesabre. We called the number given 1-800-832-8425 and also called bbb auto line for general motors…
Engine coolant leak, into the engine manifold,of my vehicle, resulted from defective upper intake manifold composite material degrading around the EGR stove pipe. Buick motor division of general motors corporation has issued a service bulletin, #01-06-01-007a-(07/18/2001), document id#812024, pertaining to this exact type of engine manifold defect in 1998 buick lesabre automobiles. On september 3, 2003, the EGR stove pipe failed in my 1998 buick lesabre, allowing engine coolant to enter the engine manfold. I formally request that your agency immediately begin an investigation into this defect, in order to proceed toward ordering a recall of this vehicle.
Vehicle had been losing coolant since 1998. Vehicle had been to dealer for repairs at least seven times. The gas recirculation valve (EGR) port was made of plastic, and when it melted, coolant seeped into the engine. *ak consumer received reimbursement of $479.99 from mc clellon buick after contacting the original owner. *ph
Also reported on the 1998 Buick Lesabre
Other engine problem
Other fuel system problem
Exhaust leak or fumes in the cabin
Other electrical problem
No-start or intermittent start failure
Alternator or charging system failure
How far this goes
Complaints are voluntary, so 23 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 1998 Buick Lesabre?
Across 17 owner reports that included an odometer reading, half were filed by 60,000 miles. A quarter were filed before 45,000 miles and a quarter after 65,000 miles. 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 1998 Buick Lesabre?
23 reports have been filed with NHTSA, about 0.4 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