This factory service and repair manual for the 1986 Cadillac Eldorado is built around this exact year and trim, so the procedures and specifications inside are the ones Cadillac published for your Eldorado, not a general reference pieced together across model years.
Engines covered
- 4.1L V8 (250 cu in) — OHV, naturally aspirated, gasoline
Body styles covered
- 2-door coupe
Trims covered
- Base
- Biarritz
Known issues on the 1986 Eldorado. Three recalls are on federal record for this model year. The first covers the gasoline fuel system: a replacement fuel filter connector that was not made to specification can let the O-ring seat improperly, creating an inadequate seal that can leak fuel and, near an ignition source, start a fire. The second covers the vehicle speed control linkage, where the throttle may fail to return to the closed idle position, causing loss of accelerator control and a possible crash without warning. The third covers the headlight switch tied to the Twilight Sentinel system, where an intermittent circuit can cause the headlights and instrument panel lights to go out suddenly, reducing driver visibility. Owners have filed 15 complaints for the year, and no technical service bulletins are logged. The factory diagnostic and repair procedures behind each of those systems are here.
Whether you're tracing a fuel line seal, inspecting the throttle linkage, or troubleshooting the Twilight Sentinel headlight circuit, it keeps you on the OEM procedure and the correct specification for your specific 1986 Eldorado.
THE TWILIGHT SENTINEL POTENTIOMETER (THUMBWHEEL CONTROL) MIGHT HAVE BEEN MANUFACTURED WITH ELECTRICAL CONTACTS WHICH COULD RESULT IN AN INTERMITTENT HEADLIGHT CIRCUIT.
WITH THE TWILIGHT SENTINEL SYSTEM ON, THE INTERMITTENTCIRCUIT COULD CAUSE HEADLIGHT AND INSTRUMENT P
INSTALL A NEW PART IN ONE OF THE VEHICLES CONTROL COMPUTERS TO PREVENT THIS CONDITION FROM OCCURING.
ENGINE FIRE.
THE CAR HAD AN UNDERHOOD FIRE. PLEASE EXPLAIN. TT
WHILE DRIVING THE DASH COMPLETELY WENT OUT. THE VEHICLE GAVE NO WARNING. TOOK TO THE DEALER. DEALER STATES THAT THE VEHICLE IS TO OLD. NLM
HEADLIGHTS AND DASHBOARD LIGHTS WORK INTERMITTENTLY. *AK
HEADLIGHTS AND DASHBOARD LIGHTS WORK INTERMITTENTLY. *AK
Showing the 5 most serious of 18 complaints filed with NHTSA.
