1998 Cadillac Deville Problems

What owners report

Owners of this model year most often describe headlight lens covers that come loose or fall off while driving, and engine overheating tied to coolant leaks at the head gasket area of the 4.6L Northstar V8. Many complaints come from cars with well over 60,000 miles, though the headlight and brake items appear at lower mileage; several reports also describe unintended airbag deployments and intermittent loss of power steering at low speed.

1. 1
   Exterior lighting

   Headlight lens cover detaches or falls off

   • 33 complaints (14%)
   • median 70,000 mi at 6.8 yrs old (19 state mileage)
   • filed 2000–2012

   Complaints describe the clear plastic lens cover on one or both front headlamps coming loose and flying off while driving, sometimes at highway speed. With the cover gone, water reaches the bulbs and they fail, leaving the car with no headlight on that side. Owners say dealers told them the lens is not sold separately and the whole headlamp assembly must be replaced, and several report the same failure on both sides, sometimes more than once. Reported from roughly 20,000 to 130,000 miles, with many between 40,000 and 80,000 miles; often noticed at highway speed or after rain.

   What to check: Inspect both headlamp assemblies for a loose, dried or missing lens cover and for moisture or clouding inside; push gently on each lens. Ask whether either assembly has already been replaced.

   2 excerpts from owner complaints in NHTSA records

   “I was driving on the highway when the plastic headlamp cover and seal flew off of my car onto moving traffic. I called the Cadillac dearship in which they say I have to replace the whole entire headlamp which will cost $300. The headlamp had dry cracked glue around it where it seemed like the glue got old and started to crack.”

   NHTSA complaint #10133817, filed 2005-08, 67,982 miles

   “I as driving on a farmed market road (f.m.) approx. 55 MPH. And the right headlight lens flew off the car. Luckily there wasn't any other cars behind me, and there wasn't any damage to my car and/or anyone elses vehicle. After I returned home, I checked the driver's side lens to discover it was loose as well.”

   NHTSA complaint #10462802, filed 2012-06, 93,259 miles
2. 2
   Engine cooling

   Engine overheating from coolant leaks (head gasket area)

   • 23 complaints (10%)
   • median 94,000 mi at 9.0 yrs old (13 state mileage)
   • 1 mention a crash, fire or injury
   • filed 1999–2017

   Complaints describe coolant loss, overheating and white smoke, with several owners told by dealers or shops that the head bolts had pulled or stripped in the block of the 4.6L Northstar V8, requiring major engine work or replacement. Some report the engine stalled or shut down once it overheated, and others link the sequence to a failed water pump, radiator or rusted coolant pipes through the engine block. Owners also describe high oil consumption alongside the coolant problems. Mostly reported between roughly 80,000 and 175,000 miles, often during normal driving after the car had been running a few minutes.

   1 related service bulletin

   What to check: Check coolant level and condition and look for staining or residue around the head gasket area and under the water pump; ask whether the head gaskets or head bolts have been serviced, and watch the temperature gauge on a test drive.

   2 excerpts from owner complaints in NHTSA records

   “I have a 1998 Cadillac Deville that I am putting the 3rd engine into the car due to a head gasket problem. My parents have the same car with the same problem. I have read classifieds that citizens who own the same car are forced to give the car away because of this head gasket problem. Anyone who can service this car (including a Cadillac dealership) has admitted that it is a very common problem with this car, and that there is no financially reasonable repair, and replacing the engine is usually the only recommendation. …”

   NHTSA complaint #10252671, filed 2008-12, 92,000 miles

   “Customer was driving vehicle down road, all of a sudden coming up to a stoplight car suddenly died, at the same time white smoke came billowing out the back of the car, it caused a traffic hazard in which nobody could see her car, she was rearended, as well as the guy that rearended her. The occupant of the vehicle that rearended her ended up getting his nose broken when he hit his steering wheel. …”

   NHTSA complaint #10447222, filed 2012-02, 131,423 miles
3. 3
   Fuel system

   Fuel smell or leak from the fuel rail

   • 14 complaints (6%)
   • median 103,000 mi at 8.3 yrs old (8 state mileage, few)
   • filed 2001–2017

   Complaints describe a strong gasoline smell at stops or fuel visibly leaking from the fuel rail onto the engine, with shops finding cracks or pinholes in the plastic rail or line. Owners report the rail or lines were replaced, and some note that a metal version superseded the plastic part. Reported from roughly 74,000 to 173,000 miles, often noticed when stopped at a light or after parking.

   Recall 97V183000

   What to check: With the engine running, look and smell for fuel around the fuel rail and injectors on top of the engine; ask whether the fuel rail or lines have been replaced and with which material.

   2 excerpts from owner complaints in NHTSA records

   “The consumer stated while having the fuel injector repaired, the independent repair shop personnel said the fuel rail would need to be removed in order to repair the fuel injector. Due to the fuel rail being made of plastic, there was a chance the fuel rail would break and have to be replaced. The dealership informed the serviceman the fuel rail was now being made of metal because the plastic was too weak.”

   NHTSA complaint #10147956, filed 2006-01, 173,000 miles

   “1.strong smell of gas when stopped at a red light or stop sign 2. Found to be a fuel rail leak between the no.3 and no.5 injector. Raw fuel leaking up under the hood could be ignited if there is an ignition source. (such as a back fire, leaking spark plug wire) 3. Replace fuel rail.”

   NHTSA complaint #10086409, filed 2004-08, 130,000 miles
4. 4
   Exterior lighting

   Cloudy, yellowed headlight lenses

   Mentioned in 4 of 60 sampled complaints

   Owners describe the plastic headlamp lenses turning cloudy or yellowish over time, which they say reduces nighttime visibility, especially when turning. Complaints note that dealers offered to try cleaning the lenses and, if that failed, recommended replacing both complete headlamp units at significant cost. Some owners report the clouding could not be cleaned out. Reported from about 20,000 to 133,000 miles, generally on older cars after years of sun and weather exposure.

   What to check: Look at both lenses in daylight and with the lights on; check whether light output is even and whether the lens surface is hazy or yellowed rather than clear.

   2 excerpts from owner complaints in NHTSA records

   “Headlamp lenses cloud reducing nighttime visibility for driver and for other vehicles. Polycarbonate lenses discolor and turn yellow. Problem is pervasive across most makes and models. Replacement lenses are very costly. The problem did not exist when glass headlamps were used, and replacement was inexpensive.”

   NHTSA complaint #10365635, filed 2010-11, 20,000 miles

   “- the contact has a 1998 Cadillac Deville with an odometer reading of 133000 miles and both headlight units are cloudy. The contact said that the visibility is very poor an there is no way to clean them to improve visibility. When making a left turn it becomes difficult to see. The contact took the car to the dealer (caramgo Cadillac) and he was told that both head light units need to be replaced.”

   NHTSA complaint #10178432, filed 2007-01, 133,000 miles
5. 5
   Air bags

   Airbags deploy without a crash

   • 23 complaints (10%)
   • median 96,500 mi at 8.2 yrs old (4 state mileage, few)
   • 11 mention a crash, fire or injury
   • filed 1998–2008

   Several complaints describe the front or side airbags deploying with no impact, sometimes when a door was shut or after a scraping noise from underneath the car. Owners report dealers saying the sensors were likely bad or that the problem had been seen before, and at least one owner says a repaired car deployed again later. Complaints also note the airbag warning light did not come on beforehand. Reported from about 66,000 to 177,000 miles, in ordinary driving and parking situations.

   Recall 00V217000

   What to check: Confirm the airbag warning light comes on at startup and then goes out, and ask whether the side impact sensor recall (00V217000) was completed for this vehicle.

   2 excerpts from owner complaints in NHTSA records

   “Dt: the contact's daughter was driving when the front air bags deployed. The contact's daughter said she did not run over anything in the road or impacted another vehicle or object. A police report was not taken, but they confirmed there was nothing in the road she ran over to cause the air bags to deploy. The dealer was inspecting the vehicle to determine the reason why the air bags deployed.”

   NHTSA complaint #10140699, filed 2005-10, 120,000 miles

   “Dt: the contact stated on 10-17-05 was driving when she heard a noise that sounded like a something scraped the bottom of the car. Immediately the driver's side and passenger's side air bags deployed. There were two people in the front seat of the car. No one was seriously injured. The dealer said there had been a problem in the past, but not the front. He also, said the sensors were probably bad. She did not recall an air bag light illuminating in the car prior to this incident.”

   NHTSA complaint #10140918, filed 2005-10, 121,058 miles

Buying note. These cars are old enough that condition and service history matter more than the model year itself, so have a mechanic check the cooling system, fuel rail and both headlamp assemblies before buying. Ask for records on head gasket and coolant work, and confirm any open recalls were completed.

Summary written with AI from a sample of 60 NHTSA complaints for this model year (picked at random, with complaints that state a mileage and recent ones taken first), then checked automatically against the source records. Where a problem shows a complaint count, every complaint for this model year was matched with fixed keyword rules (written with AI and tested against the sample), and the mileage, age and repair figures are calculated from those complaints; owners' figures are as stated, not verified. Other counts refer to the sample. The excerpts come from NHTSA's public complaint records and are unverified; capitalisation is normalised, NHTSA staff notes are removed, and shortened text ends with “…”. Something wrong? Request a correction.