1981 Cadillac Deville Coup 368 6.0 litre


An outstanding achievement for Cadillac in 1981


The valve train and most of the oil galleries were plugged with sludge due to failure to change the oil. 14 16 valve push rods needed to be replaced as they were plugged solid. All valve lifters were replaced as well along with the camshaft. Timing components such as timing chain and gears were also replaced.

The water pump and radiator was replace just as insurance.

The lower end (oil pan) was checked for damage and none was found. The main and rod bearings were like new with very little wear. The oil pickup screen was also replaced.

The headliner was replaced due to factory glue failure.

General Comments:

The 368 (8-6-4) is the last of the cast iron blocks Cadillac produced. With proper maintenance, this engine will last forever. Most people complain about being underpowered, and this is true. But, once you get this baby up to cruising speed, she'll shift into 4 cylinder operation and give you 23 MPG all day long.

Would you buy another car from this manufacturer? Yes

Review Date: 17th December, 2003

1981 Cadillac Deville Coupe 6.0 V-8 with 8-6-4 system


A tough, well built luxury cruiser


The water pump failed and needed to be replaced. This was inexpensive and easy to do myself.

The air conditioning system didn't work. I never had this fixed though I later discovered that the fix would have been easy had I any knowledge of auto mechanics at the time.

Had a spark plug oil fouling problem which eventually cured itself for unknown reasons.

Trunk pulldown motor was wearing down when the car was sold.

The headliner was also sagging badly.

General Comments:

This car was built like a tank. I have no doubt that it is one of the most noble cars I will ever drive. It underwent a lot of abuse from previous owners including infrequent (if ever) fluid changes. Car still ran fine at 130,000 miles when I sold it.

Cadillac's notorious boatlike handling was not missing from this vehicle. It suffered from severe body roll in hard cornering, and pitched badly under acceleration and braking.

The 6 liter engine was torquey enough to haul the car around at a decent pace, but produced a neolithic specific output of 23hp per liter. This was no doubt mostly due to the archaic emission controls which strangled the engine. This hampered acceleration greatly.

The 8-6-4 cylinder deactivation system performed very well. This is apparently rare, and the system was plagued by problems in most cars which were so equipped. The system shut down the right amount of cylinders at the right times, and helped noticeably with fuel economy.

This car's features combined to make the driving experience incredibly comfortable. Leather covered most surfaces of the car. The front and rear bench seats were huge. The car had power everything imaginable. The 8-6-4 system, cruise control, and trip computer were well ahead of their time.

Overall, very well suited to its purpose as a luxury cruiser. I miss that car, but I don't miss how slow it was.

Would you buy another car from this manufacturer? Yes

Review Date: 8th August, 2001

27th Dec 2014, 08:26

Yep, sounds like a nice car, and the V8-6-4 is rare but it shouldn't be. It was plagued by a few things early on, including stalling, rough idle, and some suspicious oil valves. Most of these problems came from a computer supplied by an outside company; apparently there were 2 of them going around. According to a good friend, the myth that they were updating chips was merely a strategy used in the lawsuit brought over the cars.