20th Feb 2005, 00:03
Six years ago, I bought a 1981 Cadillac Eldorado with the V8-6-4 and drove it for several years. The modulated engine worked perfectly, just the way it was supposed to. I knew how to disconnect the system, but never did. Although I didn't drive the car a lot, I never had any trouble with it.
6th Mar 2006, 13:00
I own a 79 Eldorado that my grandfather gave me. When I received it it was a pile of junk, but I revived it and I am still in the process. For being as old as it is the interior is like new and the paint job (amazingly) looks great. It had a few gas leaks that me and my cousin fixed with ease. I bought a new starter and I am working on getting a new alternator. I still have to replace all the belts and hoses/tubing, but it will be a fun project for me and my dad. For all You Caddy owners keep on truckin' and try not to give up on your cars even if they are a pain. As for the V-8-6-4 I never heard of it, but it sounds like it's a good idea, but just seems like it would cause problems. Don't think my 79 Eldorado has it, but I still love her.
1st Aug 2006, 13:39
I am the owner of a 1981 Eldorado, triple blue, and have been since 1982. I purchased the car in CA and now have it in Florida. It has 129,000 miles and only hoses, brakes and tune ups have been done. Never a problem with the 8-6-4. A truly great car that I may have to find a new home for in the near future and will miss it.
2nd Sep 2006, 12:49
My first Cadillac was a new 1981 Eldorado equipped with the infamous 6.0 Liter Variable Displacement Engine. It was purchased January 30, 1981 with a sticker price of $17,343.00. The first problem occurred at 1527 miles when, on a cold engine, it developed a vibration at 3 to 5 MPH when accelerating. The problem continued until April 21, 1982 at 11264 miles. During this period all modules, sensors, valves etc. were replaced. A factory representative even took the vehicle and drove it for a week and was unable to find the root of the problem. Finally the dealer, with factory assistance, put me in a 1982 Eldorado for a small amount. I still have the complete service file and a shop manual. According to the many lawsuits filed in various States, GM knew the "V-8-6-4" engines were defective in design to either stall or surge suddenly. The suits did not mention a monetary award, but did ask GM to reimburse owners for the cost of the car as well as any additional expenses created by the engine.
7th Dec 2006, 21:55
I have a 1981 Eldorado with the 8-6-4 engine. The car only has 7000 original miles on it, it almost stalls when you start move forward at an stop light, then it catches itself and off we go. I would guess that this is part of the 8-6-4 engine problem, does anyone know how to disconnect it??
26th Jan 2007, 20:06
That hesitation pulling out is probably NOT the 8-6-4 operation. Look somewhere else.
I had an 8-6-4 eldorado from 107Kmiles to 140Kmiles.
I had to clean the connectors where the wires went into the valve covers. They get greasy. That seemed to fix engine light occurrences. I learned how to reset the engine lights through the dash controls.
It ran fine. 6 cylinder mode should never have existed.
It's an out of balance firing sequence.
But truthfully, everything, but the engine was a problem- transmission went, several starters, alternator, and AC never worked. Also front suspension and one axle. It cost a fortune to run over that period. But everyone warned about the engine! That was the least of the problems!
4th Mar 2007, 04:06
I owned a 1983 Eldorado 20 years ago and sold it to buy a van for my expanding family. I still regret selling that car. However in June, 2006 I bought a Turquoise 1981 Eldorado with the white Roadster top for $800.00! It runs magnificently at 104k miles. Since then I have replaced the headliner and re-dyed the top. A minor wet-sanding of the paint and the car sparkles. To see it visit cardomain.com and view "eldo81". I also bought two '85 Biaritzs for my kids. They are very happy!
11th Mar 2007, 16:29
I have a great car, I would like to know how to disable the
V8-6-4 modulated displacement system to a straight V8.
11th Mar 2007, 18:03
That "4-6-8" engine is something from the 19th century compared to the Northstar V-8!
12th Jul 2007, 17:41
I have a 1981 Eldorado, and it has been sitting for 5 years. It will turn over with the two new batteries, but will not crank. It is a 350 diesel. Any help would be appreciated.
15th Aug 2007, 16:09
I need a PROM (programmable read only memory) for the computer in my 81 Cadillac El Dorado. I'm having trouble finding one in a local junk yard. I would really like to exhaust my options before heading to the dealer. Any suggestions?
30th May 2010, 13:25
My Grandfather left me his "1981 Cadillac Eldorado 8-6-4" 6.0 liter. I think it's a great classic, despite replacing the alternator 4 times and the battery too many times to count. It drives good and gets better gas mileage than most of the newer cars.
Main problem is when I take it out of Park and put into gear, it likes to stall, and when I leave a stop light "VERY annoying". Does anybody have any suggestions? I can't seem to fix it.
7th Sep 2011, 09:43
It seams that this guy is familiar with how to get the 8-6-4 engine to run in only 8-mode:
cadillacman@mcsmk8.com
Good luck!
29th Sep 2012, 20:46
Dead on comment about 6-cylinder mode. I used to drive a 1981 Coupe DeVille, and 4 or 8-cylinder mode was fine, but 6-cylinder mode would kick in if you cruised at 70-75 MPH, and you could feel a vibration that was absent in the other 2 modes. Annoying. No reliability issues with the engine, but 6.0 liters/368 CID was a bit small for the heft of the car.
15th Jul 2004, 19:00
I would like to add a few words in regards to the Cadillac V-4-6-8 mode. I actually never got the chance to test out the mode, because the seller stated it was disconnected to increase the power, and avoid any problems like the previous comment. I own a 1981 Edlo Barritz and it has become a very expensive car, due to all of the problems I have run into. I have replaced all of the normal stuff, but with only 92,000 original miles I have had to replace: Both Front Axle's, Timing Chain and sprocket, ever possible gasket, water pump 3times, and the alternator 3 times. With all of this work it runs like a champ and I love my car. I hope you all enjoy your rides and take care of them. I'm sure they will keep on chucking along as long as you keep up with all the problems before they lead to other issues. Good luck.