: 81 FWB Coupe 8-6-4



caddieboy
04-22-07, 01:34 AM
I might be able to buy a 1981 Fleetwood Brougham Coupe with the 8-6-4 engine in it from the original owner who is an emderly gentleman. Only 60,000 original miles and it looks it. Only rust I could find were two small areas by the windshield, slightest of bubbling and a dusting of rust on the driver's side rocker. Otherwise completely solid! It could use a good wax and shine of chrome, and when done, it will sparkle like new. The cloth top is flawless without any sign of a crack. Burgundy-ish paint, velour interior, only the stock radio, no cassette. Armrest has one big crack but otherwise looks new. Antenna doesn't go up and down. I haven't seen a coupe quite like this before. I can grab it for about $2500 US. Seems reasonable to me considering the shape it's in, but would like to hear thoughts. Oh, and he showed me the invoice for new brakes, about $450 US paid.

Aside from price, a few more questions...

1. I'm just wondering if this car will be hard on the pocketbook as I've not had much experience with the 8-6-4. I know some say it has issues but I've also read (even on here) it's a great engine. Anyhoo, seems it's been running well so far, so should it be OK, right?

2. Also curious about MPG, even though you shouldn't be concerned about fuel economy with a car like this, and I'm not, just curious. Speaking of which, it has the fuel center that tells you the info I'm presently asking about. I hope it still works!!! Seems like it take 22 seconds to go from 0-60MPH. Sounds like my '87 Brougham, but I managed to get used to driving her, although I'll miss th epower of my '92's 5.7.

3. What parts off my '87 would fit on this beast, internal and external?

Thanks in advance!!!

Bro-Ham
04-22-07, 03:20 AM
Hi,

I sold a 1981 Fleetwood Brougham Coupe last year for $2,500. It had about 240k miles yet also had about $3,000 invested in it in new parts/tires/etc. My car had constant driveability issues related to the V8-6-4 and computers and I have heard the current owner continues to have these problems. Ape Man on this forum patiently and expertly answered lots of questions about the 1981's with this engine and its electronics and I suggest making contact to get some thoughts and advice.

Good luck!

Dave

caddieboy
04-22-07, 08:51 AM
Hi,

I sold a 1981 Fleetwood Brougham Coupe last year for $2,500. It had about 240k miles yet also had about $3,000 invested in it in new parts/tires/etc. My car had constant driveability issues related to the V8-6-4 and computers and I have heard the current owner continues to have these problems. Ape Man on this forum patiently and expertly answered lots of questions about the 1981's with this engine and its electronics and I suggest making contact to get some thoughts and advice.

Good luck!

Dave

Thanks Dave! Just out of curiosity, were the driveability issues later in the life of the car, or continuously from mile zero? Since it only has about 60k miles, perhaps I can get some painfree life out of it for a number of years? When I looked under the hood, I was kinda blown away by all the "extra stuff" and I'll admit is scared me a bit.

When the car was running, there were no lights on in the Fuel Economy control area. Could this mean the car was modified to run like a regular V8? I've heard of people pulling the switch on the 8-6-4 part of things.

Other than your driveability issues, how did you enjoy the car?

The Ape Man
04-22-07, 09:24 AM
There isn't anything wrong with the 8/6/4 engine and management. Many great bargains were had by those who learned a few things about how to keep these cars running. Now the thing will be an antique so parts are getting to be an issue. They can still be had but it takes time to find some necessary running spares like the ECM. If you can do most of your own work then there is hope. If you need a mechanic for everything then consider something else. Between the shop manual and this bulliten board you will be able to repair issues which WILL come up. Letting a mechanic guess and learn on your car will empty your bank account for sure.
That car is worth plenty if you don't unearth any more defects. Rust by the windshield is very unusual in these years. Look for body work and unmatched paint. The MPG panel lights should still be working after the 8/8/8 modification. Hold the off and warmer buttons on the climate control for a few seconds with the ignition in the run position and the climate control head should start to spit out any codes. It will then proceed to the "70" series of diagnostics where a bunch of switches can be checked. You can ignore this for now.
I searched for a clean FWB Coupe for 5 years before finding one with zero rust. They all seem to develop rust right where the vinyl top meets the rear quarter.
If you can take your time with the sale and post detailed pictures then maybe we can give it a thumbs up or down.

Good luck.

caddieboy
04-22-07, 09:38 AM
There isn't anything wrong with the 8/6/4 engine and management. Many great bargains were had by those who learned a few things about how to keep these cars running. Now the thing will be an antique so parts are getting to be an issue. They can still be had but it takes time to find some necessary running spares like the ECM. If you can do most of your own work then there is hope. If you need a mechanic for everything then consider something else. Between the shop manual and this bulliten board you will be able to repair issues which WILL come up. Letting a mechanic guess and learn on your car will empty your bank account for sure.
That car is worth plenty if you don't unearth any more defects. Rust by the windshield is very unusual in these years. Look for body work and unmatched paint. The MPG panel lights should still be working after the 8/8/8 modification. Hold the off and warmer buttons on the climate control for a few seconds with the ignition in the run position and the climate control head should start to spit out any codes. It will then proceed to the "70" series of diagnostics where a bunch of switches can be checked. You can ignore this for now.
I searched for a clean FWB Coupe for 5 years before finding one with zero rust. They all seem to develop rust right where the vinyl top meets the rear quarter.
If you can take your time with the sale and post detailed pictures then maybe we can give it a thumbs up or down.

Good luck.

Thanks Ape Man! My mechanic now owns an 80 sedan with the 8-6-4 which he and his partner have worked on for quite a long time. He said he's had no serious issues, but maybe he thought I might want it. I do have a friend who has taught me and helped me do tune ups on my car. He has his own makeshift garage and quite knowledgable, so I could go to him when necessary.

I'm starting to think more about this purchase and whether or not I want to go down this road. So far all the cadillacs I've owned have driven like a dream and relatively low maintenance. Since I'm not in any hurry, would you advise waiting to find a Coupe with something in it where parts are relatively available?

My intention is to use this car as a daily driver and in the winter so I can keep my 1992 Brougham in mint condition. I love the way it looks, but I'm not sure I'll love the way it works, if you know what I mean. While I do have options with regards to maintenance, I'm so used to cars that just need oil and regular maintenance. So does this Coupe require more maintenance than the non-8-6-4 caddies out there?

The Ape Man
04-22-07, 11:08 AM
If your mechanic has an '80 with an 8/6/4 then that would be pretty unusual. The only year these were used in was 1981 except for later limosines.
If you want a winter beater then consider a 77,8,9 with a 425. You could get a CDV. The only year which you can have a compuker free FWB RWD coupe would be 1980. These are pretty hard to find. Production numbers were low that year. I have one here. Later years had the HT-4100. Just look at that section of this board if you are thinking along those lines. Again, you would want to stockpile a few parts for running spares after 1980. The full time 8 clyinder modification has nothing to do with a dark display.

caddieboy
04-22-07, 11:18 AM
If your mechanic has an '80 with an 8/6/4 then that would be pretty unusual. The only year these were used in was 1981 except for later limosines.
If you want a winter beater then consider a 77,8,9 with a 425. You could get a CDV. The only year which you can have a compuker free FWB RWD coupe would be 1980. These are pretty hard to find. Production numbers were low that year. I have one here. Later years had the HT-4100. Just look at that section of this board if you are thinking along those lines. Again, you would want to stockpile a few parts for running spares after 1980. The full time 8 clyinder modification has nothing to do with a dark display.


Sorry, my mechanic has an 81 sedan with rhe 8-6-4.

I saw an ad for am 82 Coupe de Ville which I guess has the 4.1 liter V-8 engine. From what I can tell, it also has the Fuel Data Panel which I love!

I guess I should keep looking and find a Coupe with easy to find parts and an easier to work on engine. Thanks for being so helpful!!! I really appreciate it!!!

The Ape Man
04-22-07, 11:24 AM
If the car has the data panel then it must be DEFI so it's an 8/6/4 or an HT-4100. Maybe you can find a converted HT-4100 car. There should still be a few out there. Dunno how your local laws would treat this though.

caddieboy
04-22-07, 11:47 AM
If the car has the data panel then it must be DEFI so it's an 8/6/4 or an HT-4100. Maybe you can find a converted HT-4100 car. There should still be a few out there. Dunno how your local laws would treat this though.

I think the '82 has the HT-4100. Just called the guy and when I asked his name, he said to call if I was interested in seeing the car. He also mentioned if I showed up with cash we could work something out. I don't get an easy feeling, so I'm going to forget about it.

I think I'll just bide my time, winter is a long way off. I have tons of time this summer to travel and maybe pick something up in the larger American market. Just keep my ear to the grindstone and watch out for something. I should consider a 77,78,79 as you mentioned. A calculator and gas reciepts and odometer can be my fuel data center.

The Ape Man
04-22-07, 02:01 PM
Calculator and a couple of fill-ups has better accuracy too. I've seen some very interesting fuel economy claims from folks without a calculator.

caddieboy
04-22-07, 03:11 PM
Calculator and a couple of fill-ups has better accuracy too. I've seen some very interesting fuel economy claims from folks without a calculator.

Agreed! But I'll always enjoy Fuel Data Systems.

jayoldschool
04-22-07, 04:22 PM
The mileage/cyl display works fine on my 81 FWB coupe. It always is displaying "8" - the cylinder deactivation has been... deactivated. I would like to reconnect it, and use a switch to avoid the "6" stage. I am not sure, however, if the wire is disconnected/cut, or if the ECM is different. I will dig into it this summer...

z06bigbird
04-22-07, 10:42 PM
I might be able to buy a 1981 Fleetwood Brougham Coupe with the 8-6-4 engine in it from the original owner who is an emderly gentleman. Only 60,000 original miles and it looks it. Only rust I could find were two small areas by the windshield, slightest of bubbling and a dusting of rust on the driver's side rocker. Otherwise completely solid! It could use a good wax and shine of chrome, and when done, it will sparkle like new. The cloth top is flawless without any sign of a crack. Burgundy-ish paint, velour interior, only the stock radio, no cassette. Armrest has one big crack but otherwise looks new. Antenna doesn't go up and down. I haven't seen a coupe quite like this before. I can grab it for about $2500 US. Seems reasonable to me considering the shape it's in, but would like to hear thoughts. Oh, and he showed me the invoice for new brakes, about $450 US paid.

Aside from price, a few more questions...

1. I'm just wondering if this car will be hard on the pocketbook as I've not had much experience with the 8-6-4. I know some say it has issues but I've also read (even on here) it's a great engine. Anyhoo, seems it's been running well so far, so should it be OK, right?

2. Also curious about MPG, even though you shouldn't be concerned about fuel economy with a car like this, and I'm not, just curious. Speaking of which, it has the fuel center that tells you the info I'm presently asking about. I hope it still works!!! Seems like it take 22 seconds to go from 0-60MPH. Sounds like my '87 Brougham, but I managed to get used to driving her, although I'll miss th epower of my '92's 5.7.

3. What parts off my '87 would fit on this beast, internal and external?

Thanks in advance!!!

Did you ever wonder why GM unloaded that car after only a short period of time? If you were a master mechanic with tons of contacts and a network to locate parts, that would still be a gamble for anybody.

$2500 is a lot of money for an old car that is replete with problems. If that engine was that good, why did GM unload it? They did not give up the 5.0 or the 5.7. They even kept the 4.1, 4.5, and 4.9 around for several years. Same with Northstar.

I had to put it this way, but ARE YOU OUT OF YOUR MIND?????

Please don't take that personally. Hell, you can locate almost any other Caddy and be happy. (Skip the 4100.) Fleecewood Broughams up until 91 are reliable and pretty. 92 + Fleecewoods are also nice. 95 and 96 run on regular. Even FWD Caddies are good, esp thru 93 or 94 with 4.5 and 4.9. I would skip the early Northstars because of POTENTIAL cooked engine problems.

That car with 4.6.8 will be a money pit.

Sorry.

caddieboy
04-22-07, 10:52 PM
Did you ever wonder why GM unloaded that car after only a short period of time? If you were a master mechanic with tons of contacts and a network to locate parts, that would still be a gamble for anybody.

$2500 is a lot of money for an old car that is replete with problems. If that engine was that good, why did GM unload it? They did not give up the 5.0 or the 5.7. They even kept the 4.1, 4.5, and 4.9 around for several years. Same with Northstar.

I had to put it this way, but ARE YOU OUT OF YOUR MIND?????

Please don't take that personally. Hell, you can locate almost any other Caddy and be happy. (Skip the 4100.) Fleecewood Broughams up until 91 are reliable and pretty. 92 + Fleecewoods are also nice. 95 and 96 run on regular. Even FWD Caddies are good, esp thru 93 or 94 with 4.5 and 4.9. I would skip the early Northstars because of POTENTIAL cooked engine problems.

That car with 4.6.8 will be a money pit.

Sorry.

There's no reason for me to take it personally, I haven't bought the car. And I'm not going to. I asked the questions, got the answers I expected, and all is well in the world. Mind is in head and intact. :)

Thanks for your take though. I treat all advice as gold. I'm not a big fan of the FWD caddies, sold my dad's 90 Fleetwood which I simply didn't like even though it had zero issues. I have a '92 Brougham but don't plan on driving it in the winter. I like the look of the big body coupes, we'll see what I find and what I end up doing. I have a solid 4 months to find something, which is pleanty of time to look around. :thumbsup:

The Ape Man
04-23-07, 09:25 AM
problems.

That car with 4.6.8 will be a money pit.

Sorry.

Please tell me exactly what components on an 8/6/4 make it a money pit verses other Cadillacs of the same age. I must have missed something all these years. :)

Pianoman72
04-23-07, 01:10 PM
Hey Ape Man, I'm a lurker on here. I read this article the other day and I thought it would be relevant to this discussion.

It says the major flaws in the 8-6-4 system are poor resulution of the ECU, and fuel provided to deactive cylinders.

http://autospeed.drive.com.au/cms/A_2618/article.html

Jonas McFeely
04-23-07, 03:18 PM
My digital fuel guage in my Brougham has saved my ass more times than i can count. My analogue guage likes to say there is way more gas than there actually is. I only use the "miles until empty" setting,ive found its very accurate. When it dips below 41 miles to go, it just says L, which is good, lets me know i need to get gas very soon. When i put it on the MPG setting,it just spews out nonsense. It says im getting between 25-45mpg consistantly. The 80's were tight.

yobee
04-23-07, 09:09 PM
say ive got an 81 fwb v-8-6-4. i havent had any major problems. bought it with 35k original, im up to 60k right now after nearly 3 years. the only work ive had to do besides regular maintenance, is valve cover seals, an exhaust manifold, and a catalytic converter. custom stuff is a whole other story, but its a daily driver so far so good(knock on wood) i say sure why not.haha. besides if anything ever goes seriously wrong. small block chevys sure are cheap motors to build!!hahaha

Old Fleetwood
04-23-07, 09:14 PM
What kind of crap do you have to go through for State Emissions Inspection on a motor Change like that?
Here in the People's Republic of Connecticut, a couple of friends have found it to be a real nightmare.

Jonas McFeely
04-24-07, 04:35 PM
What kind of crap do you have to go through for State Emissions Inspection on a motor Change like that?
Here in the People's Republic of Connecticut, a couple of friends have found it to be a real nightmare.

In Florida you can do whatever the hell you want to whatever the hell you want. No inspections whatsover. I drove around for 4 months with no bumpers.

bicentennialcadillac
04-24-07, 05:33 PM
In Florida you can do whatever the hell you want to whatever the hell you want. No inspections whatsover. I drove around for 4 months with no bumpers.

Same here in Kentucky. Gotta love it.

The Ape Man
04-24-07, 05:41 PM
Hey Ape Man, I'm a lurker on here. I read this article the other day and I thought it would be relevant to this discussion.

It says the major flaws in the 8-6-4 system are poor resulution of the ECU, and fuel provided to deactive cylinders.

http://autospeed.drive.com.au/cms/A_2618/article.html

Your article posting is interesting. The people on this board's engine section who are discussing trying this idea on larger Cadillac engines should read it. It addresses the major reason why they are wasting their time. It does not however show any reason why an 8/6/4 would be less reliable or more costly to run than other cars of the era. I'm still waiting for the list of failures which could be expected to make the 8/6/4 such a bad choice.

The Ape Man
04-24-07, 05:42 PM
My digital fuel guage in my Brougham has saved my ass more times than i can count. My analogue guage likes to say there is way more gas than there actually is. I only use the "miles until empty" setting,ive found its very accurate. When it dips below 41 miles to go, it just says L, which is good, lets me know i need to get gas very soon. When i put it on the MPG setting,it just spews out nonsense. It says im getting between 25-45mpg consistantly. The 80's were tight.

Now all they need there is an idiot light that says "You sir, are kicking the crap out of your fuel pump."

Jonas McFeely
04-24-07, 09:12 PM
Now all they need there is an idiot light that says "You sir, are kicking the crap out of your fuel pump."


Excuse me for not being able to keep the tank full at all times. Ive been doing it this way for over 2 years,and have ran it dry more times than i'd like to admit. The fuel pump has held up well,and the car is running and driving better than ever.I try not to let it get really low,but sometimes i just dont have the money go fill her up.

I appreciate the advice,but you could have done without the "idiot light" part.

All that did was make you look like a snobby jerk off. Or at least thats what i got from it.

jayoldschool
04-24-07, 10:48 PM
Excuse me for not being able to keep the tank full at all times. Ive been doing it this way for over 2 years,and have ran it dry more times than i'd like to admit. The fuel pump has held up well,and the car is running and driving better than ever.I try not to let it get really low,but sometimes i just dont have the money go fill her up.

I appreciate the advice,but you could have done without the "idiot light" part.

All that did was make you look like a snobby jerk off. Or at least thats what i got from it.


LOL

He wasn't calling YOU an idiot! The accepted term by just about anyone that is into cars for dash lights (as opposed to gauges) is... IDIOT LIGHT.

For a little proof, here is a quote from Wikipedia: "Idiot light is a mildly derogatory term that refers to a simplistic method of displaying information about a system (e.g. an engine, or a piece of factory equipment). Usually found in display panels, such as an automobile dashboard, idiot lights consist of an illumination source (usually an incandescent light bulb or an LED) with an explanatory symbol or text label. An "idiot light" will only turn on after a malfunction has occurred, providing no warning in advance, nor details of the malfunction's extent afterwards."

He's right, though - running your tank low means the pump isn't covered by gas (which cools it). Really bad. Remember, on these cars, half a tank on the gauge means a quarter of a tank left.

Jonas McFeely
04-25-07, 04:23 AM
He's right, though - running your tank low means the pump isn't covered by gas (which cools it). Really bad. Remember, on these cars, half a tank on the gauge means a quarter of a tank left.

Im not some idiot driving a Hyundai,i know fuel cools the fuel pump.Life doesnt permit me to keep my tank full at all times. Ive been doing it this way for over 2 years,and my fuel pump hasnt failed me yet.When it does,i'll make a thread explaining how i dumb i am and how right you guys were.

jayoldschool
04-25-07, 08:35 AM
Im not some idiot driving a Hyundai,i know fuel cools the fuel pump.Life doesnt permit me to keep my tank full at all times. Ive been doing it this way for over 2 years,and my fuel pump hasnt failed me yet.When it does,i'll make a thread explaining how i dumb i am and how right you guys were.

You are way too bent out of shape on this. No one is calling you names, we are just trying to be helpful. Relax. If you want to run your tank dry, go ahead. I don't care. Maybe others who read this thread will find it helpful.

Jonas McFeely
04-25-07, 03:20 PM
You are way too bent out of shape on this. No one is calling you names, we are just trying to be helpful. Relax. If you want to run your tank dry, go ahead. I don't care. Maybe others who read this thread will find it helpful.

Yes,one of the many faults of the internet. I was not getting bent out of shape. Maybe a little annoyed.But i appreciate your concern(really,not sarcasm in any way) and appologize if i "sounded" hostile.

Old Fleetwood
04-25-07, 03:28 PM
Ahhh, Mister McFeely - - -
The first car I ever bought with my own (paper route) money was an old 1948 Hudson.
It was one of the very first cars with "idiot lights." In fact it also had TWO glove compartments, one on each side of the dashboard with the gauges in the middle.
And when the idiot lights - one for oil pressure, one for amp discharge - came on, they were apparently controlled by a relay under the dash, because they came on with a distinct and LOUD click.
Yessir, I loved that old maroon bathtub.