Project thread: 1979 Coupe DeVille Phaeton (a thread 7 years in the making... kinda)
Cadillac
 

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds / (Old System)

Cadillac Technical Archive | Cadillac Dealers | Cadillac Reviews | Cadillac Dealer Reviews | Cadillac Vendors

CadillacForums.com is the premier Cadillac Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Page 1 of 8 1 2 3 4 5 6 7 8 LastLast
Results 1 to 15 of 116
Like Tree64Likes
RWD 19xx-1984 DeVille and Fleetwood,
1985-1996 Fleetwood and Brougham Forum Discussion, Project thread: 1979 Coupe DeVille Phaeton (a thread 7 years in the making... kinda) in Past Cadillac Vehicle Discussion; Welcome! So, I decided it would be a good idea to start an official, consolidated "project thread" for my Phaeton. ...
  1. #1
    Benzilla's Avatar
    Benzilla is offline Cadillac Owners Connoisseur
    Automobile(s): '79 Phaeton, '90 Brougham, '79 CDV
    Join Date
    Oct 2005
    Location
    Chattanooga, TN
    Posts
    4,288

    Project thread: 1979 Coupe DeVille Phaeton (a thread 7 years in the making... kinda)

    Welcome!

    So, I decided it would be a good idea to start an official, consolidated "project thread" for my Phaeton. Until now I had just started separate threads, or posted bits in the picture threads. The only problem with doing that, is that you'd end up with entire threads for simple questions, and all of the smaller details & triumphs slipping through the cracks. I'm thinking of wrangling all the old threads I can find that are relevant, & posting links here, thus keeping everything together except special concerns / slightly unrelated content. I'm going to do a quick summary of my history with the car, then probably do featured posts with greater detail about specific old & new subjects as time goes by. I'm hoping this will be a thread with lots of useful information about the sleek modern classic 1977-79 425 Cadillacs that are still favorites for so many of us.

    ...You might want to make a drink & get comfortable, we may be here a while.

    Personal History:
    Before watching the movie 'Goodfellas', I had no idea what a Phaeton was. When I first saw it, I just thought "oh hey, someone put a full cloth top on a '79 Coupe DeVille... that looks kinda badass!" A couple months later I was looking around online & stumbled upon a description of what the Phaeton was. Right then, I knew I wanted to find one. I started looking officially in 2005, but most of the ones I found were white with the blue top (apparently referred to as the "Nautical look"), and I was already set on 'Western Saddle Firemist'.

    So naturally, when my friend Chad found this one on eBay, I jumped on it. The downside was a well traveled 216,000 miles on the original engine and rebuilt trans, and that the car was in California... while I'm in Tennessee. But who has time for such trivial details? So... another $1000 in shipping later, on June 7th 2006, I took delivery of my new iron muse. I also have to thank our very own Craig (77CDV) for driving up and inspecting the car in Ventura, CA before it was delivered, and taking more pictures for me. A computer crash ate the pics from him, but I still have the eBay pictures.
    (eBay pictures)








    Love at first sight






    So there it was! Unfortunately, the seller didn't mention to me that the battery was dead, alternator belt not included, and alternator itself on life support... I was just sad I didn't get to drive it home yet. One pensive night later, I had it towed to a shop two blocks down. Shop replaced the missing belt, put on an Interstate battery, replaced a sketchy freeze plug, repacked a front wheel bearing; and on June 8th, 2006, I drove home deliriously happy with my new time-machine. The fact that the seat was stuck 8 inches too far back, and that I had to keep my foot slightly on the throttle at all times to stay running had no apparent effect on me. You'd think I was driving a Ferrari by the look on my face. Details were trivial, I was still too busy cranking Frank Sinatra through the 8-track & marveling over guide-matic headlamps.




    My Phaeton came with it's original dealer invoice (From Hillcrest Motors, Beverly Hills, CA.) with a note scribbled about the custom "Classic Cadillac" grille and it's price of $1250 (I'll never understand the appeal, so I replaced it with an original version & sold the Rolls knockoff on eBay). Even the original owners manual was there, with a note about "Only 2,400 Phaeton Coupes" above A Cadillac customer-service number, with the name "Chuck". There was also a fascinating chromed, extendable, cross-car, hook-to-hook clothes hanger (There's a good idea... just block the rear view completely with a nice wall of leisure suits... Safety first!); One set of dark brown velour seat covers, probably left from before the seats were recovered in 1998; and a cheap cloth car cover, among other things. The California plates that were on it dated back to 1989. I've often wondered what the original plates might have been & where they went (vanity plates perhaps?). I was very lucky that it still actually has the original plate frame from the factory, as mentioned on the invoice. The grippy steering wheel cover & tan super-store floor mats were the first things to go...




    Annual summary:
    2006: Carb rebuilt (twice... Horribly, by a very bad, BAD mechanic); new power steering pump; replaced a weak freeze plug; first set of spark plugs, dist cap; front brake pads; first new starter; misc other.

    At cruise-in, the first week I had it.


    ________
    2007: Original alternator rebuilt; New 215-75-R15 Dimension IV 1.3" whitewall tires; Urethane clear coat paint job & bodywork; replaced dealer-installed grille with a stock one; headlight short fixed;
    A.I.R pump replaced (didn't know at the time that I could just bypass it, or that it came with the California emissions kit); rear springs & shocks replaced with Impala SS springs, and Hijacker air shocks (details in thread); blinker module replaced; installed a set of Lloyds Ultimat floor mats. The cardboard trunk walls were looking a big saggy, so I carpeted them with some of that grey roll up carpet you can get at about any super-store or parts store, and some spray adhesive. Six years later, they are still holding up well.



    First & only car show to date.



    2008: New fuel pump, 2nd new starter.

    2009: Alternator replaced with rebuilt one. (and probably other stuff that I don't remember)

    2010: Transmission rebuilt after it decided it was done with all of this 'shifting' business. Unrelated front-end collision & repairs. (details in thread)





    2011: New alternator drive belt after the old one shredded & wrapped itself around the fan.

    2012: New 120 amp alternator (that makes 3); new starter (...also 3); new battery (2nd one).
    New exhaust pipe & muffler; front end alignment & center-link replaced; new spark plugs, more plug wires, cap & rotor; installed rear-window 3rd brake light; coolant flush, correct 195 degree thermostat, replaced heater core & hoses; new windshield-wiper motor (Yet my delay function still doesn't work right).

    2013: I replaced the distributor with a re-manufactured 4-pin federal version in order to bypass the Electronic Spark Selection (aka E.S.S) box, which is an annoying CA emissions feature that had WAY to much authority over engine timing advance.
    Lots of vacuum hose replacement & routing corrections; new ceramic brake pads, flex hoses, master cylinder & power booster. I replaced the anemic, lean-jetted & generally toasted California carburetor with one from a federal '78 DeVille that I rebuilt specifically for this. Rather proud, it's my first carburetor. But more on that later..

    Pictures from around April, 2013.








    now, if I don't go ahead and post this, I might never finish! I'm already avoiding the urge to divide this first post into separate chapters, lol. Sorry for the pic spam. Possible sub-topics might include things like shock replacement, front end rebuilding, sway bars, AC work, valve cover gaskets, carburetor rebuilding, federalizing a California Cadillac, & much more. Stick around and ask questions!

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    csbuckn is offline Cadillac Owners Master
    Automobile(s): 84 Coupe w/500
    Join Date
    Jan 2008
    Location
    Minneapolis
    Posts
    5,132

    Re: Project thread: 1979 Coupe DeVille Phaeton (a thread 7 years in the making... kin

    Man, I just love the 77-79 interior. The pic of the caddy on the trailor makes it look like a trophy to me.
    Cadillac_Fan, Benzilla and 77CDV like this.

  4. #3
    Cadillac_Fan's Avatar
    Cadillac_Fan is offline Cadillac Owners Fanatic
    Automobile(s): 92 CdV Spring Edition;92 Brougham d'E 305;98 Seville STS
    Join Date
    Jun 2005
    Location
    Indiana
    Posts
    482

    Re: Project thread: 1979 Coupe DeVille Phaeton (a thread 7 years in the making... kin

    Outstanding write-up. I still think of your Denise (sp?) story, too.

    Is that a tach or temp guage? Did you install it or was it installed prior to your acquisition? I see you've changed up the hood ornament too (standalone crest vs. wreath-and-crest), what is on it presently? (I know it is not original, yet I like the wreath and crest ornament on the DeVilles.) I sorely miss my '79 Brougham. I'd happily surrender my '92 Brougham d'Elegance to have another '79!

  5. #4
    deVille33 is offline Cadillac Owners Connoisseur
    Automobile(s): 1977 Coupe (blue), 1977 Coupe (yellow), 1977 Coupe (green)
    Join Date
    Mar 2006
    Location
    Western Massachusetts
    Posts
    1,368

    Re: Project thread: 1979 Coupe DeVille Phaeton (a thread 7 years in the making... kin

    Ben, Great pictorial and history recount. Have always taken a personal interest in both your listed projects. I take pics of mine, but fail to find time to document them.

  6. #5
    Benzilla's Avatar
    Benzilla is offline Cadillac Owners Connoisseur
    Automobile(s): '79 Phaeton, '90 Brougham, '79 CDV
    Join Date
    Oct 2005
    Location
    Chattanooga, TN
    Posts
    4,288

    Re: Project thread: 1979 Coupe DeVille Phaeton (a thread 7 years in the making... kin

    Thanks guys! I'll be delighted to answer questions very soon, but for now, I have a pressing "riddle" that I need some ideas on:

    I've been having a strange issue... Most of the time, the car has a predictable amount of throttle response, however I've been noticing for quite some time now the following issue:

    In the course of a day, if I take the car for a long enough drive to reach & hold full operating temp for a while, then drive home & park it for a while (maybe a few hours), when I go back out for the second drive of the day, the car has a VERY noticeable power increase for a while after startup.

    It's as if my throttle input is being amplified, and the car feels extremely responsive & peppy. If I keep driving, this phenomenon slowly goes away within about 5-10 minutes of driving, and I'm left with the performance level that I've come to expect as normal. It's like while the power influx is happening, the engine isn't working nearly as hard to accelerate, and there's a big difference in that "butt-to-the-seat" feeling of propulsion.

    Facts:

    I don't get any kind of power flux during the 1st trip of the day, ever. It's only after it's been heated up fully, and cooled down to some extent.

    This problem has transcended a carburetor swap, and full ignition system replacement. Meaning that unless the carb I rebuilt has the same theoretical problem that I'm somehow overlooking; carb adjustments make no difference in this erratic performance. Choke, linkage & all other variables have been adjusted according to the factory service manual.

    The car still wears what I believe to be the original catalytic converter, which makes me wonder about heat sensitive back-pressure fluctuation of some kind?

    The engine has 234,000 miles on it, with no known complete rebuild. Could this be some kind of compression issue or other internal disturbance?

    I've had a long running off & on battle with detonation. I think I have it solved, but that is to point out that the detonation would also come and go seemingly randomly. However, the pinging always seemed to vanish while the car was having a "power influx"

    ________

    Any ideas, guys?

  7. #6
    Mark 78 Coupe is offline Cadillac Owners Fanatic
    Automobile(s): 1978 Coupe De Ville, 1993 Fleetwood
    Join Date
    Sep 2011
    Location
    Pittsburgh/Florida
    Age
    55
    Posts
    430

    Re: Project thread: 1979 Coupe DeVille Phaeton (a thread 7 years in the making... kin

    Sorry I can't offer any advice on your engine problems, but I wanted to give a big thumbs up for your persistence. I also have a Coupe De Ville ( a 78 in my case ) with but 44,000 original miles on it. It is sitting in my garage, waiting for the next year ( I hope ) when I will repaint it and once again get it on the road. Last year I replaced the original radiator, hoses and belts, along with a new battery, and it starts and runs amazingly well for a car that has been largely unused for the last 20 years. I still open the door and marvel at the beautiful, comfy whore red leather seats, and look forward to the day once again when it is a running and driving car. You are an inspiration!
    Benzilla likes this.

  8. #7
    Fleetwood472 is offline Cadillac Owners Fanatic
    Automobile(s): 78 Fleetwood w/ FI 472/ Switch pitch TH400
    Join Date
    Aug 2005
    Posts
    235

    Re: Project thread: 1979 Coupe DeVille Phaeton (a thread 7 years in the making... kin

    Hey Ben,

    Nice job you're care looks great! When is the last time you have changed the EGR valve on it? If it has been a long time it would probably be a good proactive option to try which could rule out some stuff. They're fairly cheap and easy to change. That may be contributing to some of the detonation issues. Also there is a thermal switch that is in-line from the carb to the EGR valve. It opens at a specific temp when the engine is warmed up and closes when the engine cools down. If it's opening or closing at the wrong times this could be the problem. It is not electronically controlled but just has some sort of metal spring that opens in it when the temp rises. That might be another thing to try replacing especially since the engine has that kind of mileage on it. I would also bet if that's the original converter it may be getting plugged up causing power issues. One common issue is the advance weights sticking in the distributor but that shouldn't be a problem for you since you've replaced it fairly recently with a rebuilt distributor.
    Benzilla likes this.

  9. #8
    Benzilla's Avatar
    Benzilla is offline Cadillac Owners Connoisseur
    Automobile(s): '79 Phaeton, '90 Brougham, '79 CDV
    Join Date
    Oct 2005
    Location
    Chattanooga, TN
    Posts
    4,288

    Re: Project thread: 1979 Coupe DeVille Phaeton (a thread 7 years in the making... kin

    I checked & cleaned the ERG valve a few thousand miles ago, everything seems fine there.

    I didn't think to mention, the vacuum advance is run direct manifold vacuum. This is a change I made. The car was originally from California, with all the special equipment, so the vac advance ran through a thermal vacuum switch (TVS), disabling cold operation advance. The same TVS also cut cold operation of the EGR valve. I eliminated the TVS entirely & ran the EGR valve direct from the carb, as the federal versions were routed.

    Here's the original pinging thread
    , started back in May of 2012. It starts at the absolute beginning, and is quite a book:
    http://www.cadillacforums.com/forums...afoam-etc.html

    And another thread started further along, with more knowledge of the problem, started (OFF-SITE) in March of 2013:
    http://forums.cadillaclasalleclub.or...topic=123917.0


    So, anyway... I made a discovery earlier. I was out re-checking vacuum lines for leaks, because I had this idea that perhaps an intermittent vacuum leak was causing engine vacuum at idle to fall lower than that required for the vacuum advance can to properly seat all the way, & throwing off the advance amount. In the process of testing this theory, I discovered that my 8-month old distributor's vacuum-can has, at some point in the recent past, gone belly-up, and is now a giant vacuum leak. Now... Though this is not the main culprit for the situation at hand, it might explain a dieseling (run-on) problem I've had the last couple of weeks, assuming the vacuum advance broke at the same time the dieseling began.

    In light of this discovery, I've been trying to determine what vacuum advance I should replace it with. I've heard that most generic non-adjustable replacements pull too much advance, around 22 degrees, where as my service manual says the original only pulled 16 degrees on federal cars, less on CA. However I've also heard that the adjustable ones have to be adjusted to extremes to get the advance curve close to GM's original, because they pull full vacuum too soon, at too few hg, possible causing part-throttle-detonation. I have no proof of either of these statements. For now, I'll see if the advance-can on my original distributor is still holding air, and if so; put that on until I choose a replacement.


    -Ben

  10. #9
    77CDV's Avatar
    77CDV is offline Cadillac Owners Master
    Automobile(s): 77 CDV, 06 DTS III, 69 FWB
    Join Date
    Mar 2006
    Location
    Newbury Park, CA
    Age
    42
    Posts
    9,166

    Re: Project thread: 1979 Coupe DeVille Phaeton (a thread 7 years in the making... kin

    Good to see you bring us all up to date on the Phaeton, Ben! You have every right to be proud of what you've accomplished with her. I doubt there's a finer 77-79 Cadillac in all TN!
    Benzilla likes this.

  11. #10
    silverfox103's Avatar
    silverfox103 is offline Cadillac Owners Fanatic
    Automobile(s): 96 Fleetwood & 07 CTS, 94 Roadmaster Wgn & 94 Caprice Wgn
    Join Date
    Aug 2012
    Location
    Littleton, NH & St. Simons, GA
    Age
    65
    Posts
    170

    Re: Project thread: 1979 Coupe DeVille Phaeton (a thread 7 years in the making... kin

    Really enjoyed the pictures and story of your Caddy. 234K on that car? Sorry I don't believe that. She's a beauty.

    Tom C.
    Benzilla likes this.

  12. #11
    Bro-Ham's Avatar
    Bro-Ham is offline Cadillac Owners Connoisseur
    Automobile(s): 1979 Cadillac Sedan deVille d'Elegance
    Join Date
    Oct 2005
    Location
    Sarasota, FL
    Age
    46
    Posts
    3,863
    What a beauty! I love your love of cars!
    Benzilla likes this.

  13. #12
    68CaddyConv. is offline Cadillac Owners Member
    Automobile(s): 2010 CTS AWD Luxury Sedan
    Join Date
    Jun 2013
    Posts
    5

    Re: Project thread: 1979 Coupe DeVille Phaeton (a thread 7 years in the making... kin

    Thanks for sharing this Benzilla! Your Caddy looks amazing! My dad had a 79 Phaeton identical to yours when I was a kid. I recently obtained the old title and I'm trying to see if the car still exists. Thank again for posting yours. Sweet ride!
    Benzilla likes this.

  14. #13
    cadillac kevin's Avatar
    cadillac kevin is offline Cadillac Owners Master
    Automobile(s): chevy 350 powered 86 FWB, 00 safari h.t. 66 toro, 83 lesabre
    Join Date
    Dec 2010
    Location
    St. Louis, MO
    Posts
    5,623

    Re: Project thread: 1979 Coupe DeVille Phaeton (a thread 7 years in the making... kin

    that is a gorgeous car and looks exceptional for the mileage!

  15. #14
    Benzilla's Avatar
    Benzilla is offline Cadillac Owners Connoisseur
    Automobile(s): '79 Phaeton, '90 Brougham, '79 CDV
    Join Date
    Oct 2005
    Location
    Chattanooga, TN
    Posts
    4,288

    Re: Project thread: 1979 Coupe DeVille Phaeton (a thread 7 years in the making... kin

    So I installed the original vacuum advance can again, and haven't notice any power changes since then. Dieseling seemed to be caused by a slightly high idle speed.

    Next issue up, my blower motor stopped working. I know the ground wire connector is a bit wonky on mine so that's where I'll start. I also need to replace the compressor, and have someone find a possible refrigerant leak. I don't mind not having AC, but no defogger is just a hazard when it's cold out.

    Rear window defogger has never worked either. Would love to fix that, but electronics really aren't my strong suit. All I've checked is the fuse. I've dreaded having a go at the back window, because a previous owner had the three rear windows lightly tinted, and I'm not sure how to go about removing the tint without breaking the defogger strips.

  16. #15
    Bro-Ham's Avatar
    Bro-Ham is offline Cadillac Owners Connoisseur
    Automobile(s): 1979 Cadillac Sedan deVille d'Elegance
    Join Date
    Oct 2005
    Location
    Sarasota, FL
    Age
    46
    Posts
    3,863
    Quote Originally Posted by Benzilla View Post
    So I installed the original vacuum advance can again, and haven't notice any power changes since then. Dieseling seemed to be caused by a slightly high idle speed.

    Next issue up, my blower motor stopped working. I know the ground wire connector is a bit wonky on mine so that's where I'll start. I also need to replace the compressor, and have someone find a possible refrigerant leak. I don't mind not having AC, but no defogger is just a hazard when it's cold out.

    Rear window defogger has never worked either. Would love to fix that, but electronics really aren't my strong suit. All I've checked is the fuse. I've dreaded having a go at the back window, because a previous owner had the three rear windows lightly tinted, and I'm not sure how to go about removing the tint without breaking the defogger strips.
    Blower motor? Have you checked the relay? That is the only chronic issue I have with my 79 and I keep a stock of the relays since they reularly melt down.

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Bookmarks

Cadillac Posting Rules

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
Read about Lincoln | Buick | Kia Forte Forum
Need products for your Cadillac? Check out your options at the links below:

custom floor mats | Cadillac Chrome and Black Chrome Wheels | window tinting