1986 Cadillac Deville: common problems

Owners of the 1986 Cadillac Deville filed 22 complaints with NHTSA, most often about engine and cooling and powertrain. Details by component below, with sources.

Key figures

Owner complaints: 22
involving a crash: 1

What fails most often

1 Engine and cooling 41% of all complaints
2 Powertrain 14% of all complaints
3 Service brakes 14% of all complaints
4 Electrical system 9% of all complaints
5 Vehicle speed control 9% of all complaints
6 Fuel system 5% of all complaints
7 Latches, locks, linkages 5% of all complaints
8 Seat belts 5% of all complaints

Circle size and colour show each component’s share of NHTSA complaints. Schematic only, not a drawing of the exact model.

Engine and cooling: 9 complaints (41% of all).
Powertrain: 3 complaints (14% of all).
Service brakes: 3 complaints (14% of all).
Electrical system: 2 complaints (9% of all).
Vehicle speed control: 2 complaints (9% of all), 1 of them with a crash reported by the owner.

Symptoms owners describe

How many of the 22 NHTSA complaints mention each symptom (automatic count from complaint text; one complaint can mention several).

knocking, grinding or other noise2 · 9%
oil leak or consumption2 · 9%
unintended acceleration2 · 9%
engine failure or replacement1 · 5%
won't start1 · 5%
rust, corrosion1 · 5%
vibration1 · 5%

Components owners complain about

Component	Owner complaints	involving a crash
Engine and cooling	9	0
Powertrain	3	0
Service brakes	3	0
Electrical system	2	0
Vehicle speed control	2	1
Fuel system	1	0
Latches, locks, linkages	1	0
Seat belts	1	0
Steering	1	0
Structure	1	0

What owners report

Short excerpts of NHTSA complaints in the original wording. These are owner statements not verified by NHTSA; personal data removed.

Intermittent sudden accelerations, causing loss of control/accident.
Vehicle speed control · crash · 1995-03-02 · NHTSA complaint #480279
1986 cadillac deville/fleetwood abs brake system. Consumer requests that enforcement of same inspection, testing and replacement of the failed braking parts for his vehicle. The consumer stated the abs did not perform in a satisfactory manner. The consumer stated the abs was flawed.
Service brakes · 2008-10-08 · NHTSA complaint #10244848
Car developed an oil leak, I thought it was the oil pan gasket. Took it to a dealership who changed the oilpan gasket. It still leaked oil, so I removed the engine. I discovered that the block had a crack from the crank shaft to the cam shaft on the rear of the engine.
Engine and cooling · 2000-04-18 · NHTSA complaint #721437
Latch lock assembly on both driver's and passenger's sides became defective, not allowing both doors to open from the inside or outside.
Latches, locks, linkages · 1999-12-29 · NHTSA complaint #854502
Dificult steering when vehicle is cold. Also, engine leaks oil.
Engine and cooling · 1999-06-10 · NHTSA complaint #707434
Engine failed and vehicle shutdown. Owner believes a defective crankshaft caused the problem.
Engine and cooling · 1998-08-25 · NHTSA complaint #540349
Accelerator pedal intermittently sticks when applied, engine accelerates to high speed, vehicle keeps moving with brakes applied. Test driven by dealer, not duplicated.
Vehicle speed control · 1997-04-25 · NHTSA complaint #811714
While driving, driver front and rear shoulder/lap belt under normal movement causes to come undone for no reason. Tt
Seat belts · 1995-11-08 · NHTSA complaint #974757

When owners complained

NHTSA complaints by filing year. The peak shows at what age the problems show up most.

199511
19971
19982
19995
20002
20081

Comparison

By complaint count this model year ranks 7,904 of 36,656 model years in the NHTSA data (top 22% most complained about).

On average one model year of the Deville has 83 complaints (33 years in the data). This year has 22, below average.

What to check before buying

Engine and cooling. Radiator and fan after a frontal hit, coolant level and condition, overheating.
Powertrain. Shift quality under load, harsh shifts, transmission codes, CV joints.
Service brakes. Pedal feel, ABS operation, leaks, discs and hoses.
Electrical system. Scan all modules, test the battery and alternator, inspect connectors near the impact zone.

Questions and answers

What are the most common problems with the 1986 Cadillac Deville?

Owner complaints to NHTSA most often mention: engine and cooling, powertrain, service brakes. Total complaints: 22. The most frequent symptoms in complaint texts: knocking, grinding or other noise (9%), oil leak or consumption (9%), unintended acceleration (9%).

How many service bulletins (TSB) were issued for the 1986 Cadillac Deville?

NHTSA lists 0 manufacturer service bulletins for this year. A bulletin tells dealers how to diagnose or fix a known issue; it is not a recall.

Should I buy a 1986 Cadillac Deville from a US auction?

Owner complaints describe defects, not crash damage. Before bidding, check the components listed above and review the lot photos: VinWind builds a report of visible and hidden damage by VIN.

Other 1986 models

Read also

Sources: public NHTSA data (USA): service bulletins and owner complaints; YouTube: links to videos credited to their authors. Complaints are owner statements not verified by NHTSA, and describe defects rather than crash damage. Data updated 2026-11-05.