ROTTEN EGG ODOR FROM EXHAUST INSTALL NEW CAT. CONVERTER
SUBJECT: ROTTEN EGG ODOUR FROM EXHAUST (INSTALL NEW CATALYTIC CONVERTER)
VEHICLES AFFECTED: 1986-87 CADILLAC C,E,K,D,J
This bulletin supercedes Product Service Bulletin 87-641-117 to include new part numbers for Devilles, Fleetwoods, Eldorados, and Sevilles.
Some 1986-1987 De Villes, Fleetwoods, Broughams Eldorados, Sevilles, and Cimarrons may exhibit a "rotten egg" odour from the exhaust system. If present, the odour will be most evident during idle conditions.
To address this condition, it is important to first check those items which may cause a vehicle to run excessively rich. These include (but are not limited to):
o Check for normal engine operating temperature, o Check for excessive fuel pressure, o Check for incorrect idle speed, o Check for incorrect engine timing, o Check for leaking fuel injector.
Refer to the appropriate model Cadillac Service Manual, Section 6E-B, "Excessive Exhaust Emissions (Odours)" for more information.
DEVILLES, FLEETWOODS, ELDORADOS AND SEVILLES
If proper vehicle operation is verified and the odour condition persists, install a new catalytic converter (part numbers listed using the following procedure (refer to Figures 1 and 2):
1. Raise the vehicle and support the catalytic converter.
2. Disconnect the A.I.R. hose from the converter.
3. Using tool J-35976, BT-8252 or equivalent, cut the intermediate pipe at the converter as close to the weld as possible as shown in Figure 2).
4. De Ville/Fleetwood - Cut the exhaust pipe at the converter as close to the weld as possible refer to Figure 2.
Eldorado/Seville - Remove the two bolts and springs from the exhaust pipe to converter flange.
5. Remove the catalytic converter (and seal on Eldorado/Seville).
6. Collapse and remove the portion of the catalytic converter inlet/ outlet remaining in the intermediate pipe (and exhaust pipe on De Ville/Fleetwood).
7. Install the new catalytic converter. The converter inlet/outlet will fit inside the existing pipes.
8. Eldorado/Seville - Install a new exhaust pipe to converter seal, P/N 1633384. Install the exhaust pipe to converter flange bolts/springs and torque to 20 N.m (15 lbs. ft.).
De Ville/Fleetwood - Install a guillotine-type clamp, P/N 15595048, at the exhaust pipe to converter fitting. Torque to 35 N.m (26 lbs. ft.) .
9. Install a guillotine-type clamp, P/N 15595048 (except C-touring use 3634476), at the intermediate pipe to converter fitting. Torque to 35 N.m (26 lbs. ft.).
10. Reconnect the A.I.R. hose, lower vehicle, start engine, and check for exhaust leaks.
PARTS LIST:
Part Name Model P/N ------------------- --------------------- -------- Catalytic Converter De Ville/Fleetwood 25128764 Catalytic Converter De Ville Touring Coupe/Sedan 25103959 Catalytic Converter Eldorado/Seville 25128765
BROUGHAMS AND CIMARRONS
If proper vehicle operation is verified and the odour condition persists, install a new catalytic converter using the part numbers listed below.
1986-87 Brougham (federal emissions) 25103919 1986 Cimarron 25104705 1987 Cimarron 25104025
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.
