5.7 lt1 VS. FORD 4.6 which is more durable
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 3 1 2 3 LastLast
Results 1 to 15 of 31
5.0 and 5.7 Discussion, 5.7 lt1 VS. FORD 4.6 which is more durable in Cadillac Engine Technical Discussion; Ive had a 4.6 before in a grand marquis. It seems more reliable. But which one is more durable? it ...
  1. #1
    Hammondsix's Avatar
    Hammondsix is offline Cadillac Owners Fanatic
    Automobile(s): Cadillac Fleetwood 94
    Join Date
    Oct 2006
    Posts
    121

    5.7 lt1 VS. FORD 4.6 which is more durable

    Ive had a 4.6 before in a grand marquis. It seems more reliable. But which one is more durable? it seems that an all Cast iron motor would last longer than an aluminium motor but if you look at ebay it seems that there are more fords with higher milage. I saw a lincoln with 650000+ miles on it!! (but it ran on propane)

    what do you think?

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    90Brougham350's Avatar
    90Brougham350 is offline Cadillac Owners Connoisseur
    Automobile(s): 94 FWB, 93 SDV, 94 FWB (sold), 90 Brougham (sold)
    Join Date
    Jan 2005
    Location
    River Falls, WI
    Age
    29
    Posts
    3,730

    Re: 5.7 lt1 VS. FORD 4.6 which is more durable

    Either are great motors if they're well maintained. The LT1 is a tried and true small-block Chevy that will do hundreds of thousands of miles if you maintain it properly, so is the 4.6. The optispark on the LT1 maybe even makes it more reliable. Either are good motors, I don't know if I'd say there's a better engine between the two. As far as wear and tear, the 4.6 needs to spend more of its life in the higher RPM's, so the basic laws of engine wear say the 4.6 has more wear and tear on it than an LT1 if they have the same number of miles, but I wouldn't put one ahead of the other.

  4. #3
    Hammondsix's Avatar
    Hammondsix is offline Cadillac Owners Fanatic
    Automobile(s): Cadillac Fleetwood 94
    Join Date
    Oct 2006
    Posts
    121
    Thread Starter

    Re: 5.7 lt1 VS. FORD 4.6 which is more durable

    i thought the 4.6 was a newer design...

  5. #4
    I~LUV~Caddys8792's Avatar
    I~LUV~Caddys8792 is offline Moderator
    Automobile(s): 1992 Town Car Cartier & 2014 Accord LX MTX
    Join Date
    Dec 2004
    Location
    Roseville, MN.
    Age
    27
    Posts
    34,087

    Re: 5.7 lt1 VS. FORD 4.6 which is more durable

    Both are great engines, very very durable motors, probably the most durable modern american V8's ever. The LT1 does have that optispark, which is very reliable, but it's costly to repair. The early SOHC 4.6's have an oil burning issue because the valves don't seal all the way. Between the two of them, I'd probably say that the 350 is more reliable, but only very slightly more.

  6. #5
    CadiJeff's Avatar
    CadiJeff is offline Cadillac Owners Connoisseur
    Automobile(s): 1981 CoupeDeville, 2 1990 Eldorados, 1994ETC ,1992STS
    Join Date
    Feb 2004
    Location
    Nerk,Ohio
    Age
    34
    Posts
    1,072

    Re: 5.7 lt1 VS. FORD 4.6 which is more durable

    to close to call....I would say that it would depend on the owner (maint. driving style, habits ect.)

  7. #6
    Hammondsix's Avatar
    Hammondsix is offline Cadillac Owners Fanatic
    Automobile(s): Cadillac Fleetwood 94
    Join Date
    Oct 2006
    Posts
    121
    Thread Starter

    Re: 5.7 lt1 VS. FORD 4.6 which is more durable

    yeah the valve seals were bad on the 92-95 engines, but the 96- were equipped with a plastink manifold that was prone to crack. Annoying repairs but not devastating sort of like the , exhaust bolts and waterpump/distributor on the LT.

  8. #7
    Phantom&RedGoat2004's Avatar
    Phantom&RedGoat2004 is offline Cadillac Owners Fanatic
    Automobile(s): 1968 Convertible
    Join Date
    Nov 2006
    Location
    Lufkin, Tx
    Posts
    116

    Re: 5.7 lt1 VS. FORD 4.6 which is more durable

    I think they are both great engines, but my purely biased opinion says that GM is superior. Now go ask a Ford forum, and see what they say. (*_~)

  9. #8
    N0DIH's Avatar
    N0DIH is offline Cadillac Owners Master
    Automobile(s): 94 Fleetwood Brougham
    Join Date
    Aug 2004
    Location
    Rockford, IL
    Age
    47
    Posts
    7,512

    Re: 5.7 lt1 VS. FORD 4.6 which is more durable

    Newer doesn't mean better

    Quote Originally Posted by Hammondsix View Post
    i thought the 4.6 was a newer design...

  10. #9
    drewsdeville is offline Cadillac Owners Master
    Automobile(s): 2011 Crown Vic LX, 2009 Chevy Malibu 2LT
    Join Date
    Oct 2004
    Location
    Oak Creek, WI
    Posts
    5,382

    Re: 5.7 lt1 VS. FORD 4.6 which is more durable

    Since we are comparing to the LT1, we'd have to use the older 4.6's to compare. are we comparing engines or drivetrains?

    I had 2 buddies, between them, 3 Grand Marquis. Yes, strange. 2 1992's and 1 1993.

    1 1992 had 150,000 on it. Was a huge problem car. Plagued from the start. Many thousands of dollars into the transmission. It was done twice. I always found Ford's trannies to be their weakness....
    The oil pan rusted through
    Numeruous vacuum leaks
    Coil packs
    Lots of failed sensors

    The other '92 had only 70,000 on it.
    Same thing, numerous vacuum leaks
    oil pan rusted through on this one as well
    Overdrive never shifted correctly, but the rest of the tranny seemed fine
    Coil packs

    Wow, now that I am listing this stuff, these guys had identical problems, I never even realized it.

    Both used oil

    However, the 1993 was a trouble free car. That one never had a problem while he had it. Sold it at 103,000 or something like that. He gave it up for a 2000 Grand Marquis

    I can only list problems I've seen with the 4.6 because I never knew anyone with an LT1... so yeah

  11. #10
    N0DIH's Avatar
    N0DIH is offline Cadillac Owners Master
    Automobile(s): 94 Fleetwood Brougham
    Join Date
    Aug 2004
    Location
    Rockford, IL
    Age
    47
    Posts
    7,512

    Re: 5.7 lt1 VS. FORD 4.6 which is more durable

    I have 209K on my ride. Eng has no evidence of ever being opened, and for sure not since I have had it in the last 60K. Trans is stock, rear end is stock (but has a pair of badly worn axle shafts thanks to GM installing the wrong diff gasket). The only real issues that this car ever had before I got it was AC compressor. Factory one died in 2002 and replacement was bad and had to be replaced less than 1 year later.

    Engine itself, almost untouched for 209K. Even factory water pump and distributor/cap/rotor.

    Mine is a 94 Cadillac Fleetwood Brougham with the factory V4P 7000# towing package.

  12. #11
    drewsdeville is offline Cadillac Owners Master
    Automobile(s): 2011 Crown Vic LX, 2009 Chevy Malibu 2LT
    Join Date
    Oct 2004
    Location
    Oak Creek, WI
    Posts
    5,382

    Re: 5.7 lt1 VS. FORD 4.6 which is more durable

    Even factory water pump and distributor/cap/rotor.
    Is that possible??? How do you know it's factory??? The contacts on the cap and rotor wouldn't even be touching each other by now...

    But I guess, you know your car better than I. If tht's true, those contacts must be some sort of exotic metal...

    The water pump doesn't suprise me. Most cast-iron water pumps can outlast the car they are in.

  13. #12
    N0DIH's Avatar
    N0DIH is offline Cadillac Owners Master
    Automobile(s): 94 Fleetwood Brougham
    Join Date
    Aug 2004
    Location
    Rockford, IL
    Age
    47
    Posts
    7,512

    Re: 5.7 lt1 VS. FORD 4.6 which is more durable

    My distributor is under the water pump (Optispark). It has a huge cap and has a bad rap for failures. But most are at 150K+ before they do. Most cars can't even ponder going 100K on a factory cap/rotor and these cars commonly do it. I am sure it NEEDS it, but it is a major job to do it. I need to get a water pump, timing set (209K it needs it too), and distributor (common to replace with a new GM unit). Katshot said statistically they replaced them all at 142K miles for a reliability standpoint.

  14. #13
    BCs71's Avatar
    BCs71 is offline Cadillac Owners Enthusiast
    Automobile(s): 1994 Cadillac Fleetwood Brougham (some show and some go!)
    Join Date
    Oct 2003
    Location
    Chicagoland
    Posts
    607

    Re: 5.7 lt1 VS. FORD 4.6 which is more durable

    Not familiar with the 4.6 so can't comment.

    But the iron-headed LT1 engine is in livery Fleetwoods, taxi cab Caprices & 9C1 cop cars.
    I have a pal who went 297,000 miles on his ex-cop car AND ex-taxi use vehicle. Engine failure occurred because he decided to do a 100mph jaunt on the highway when the oil pump failed (taking out the engine in the process). He could of went much longer on that stock 300K mile abused multiple fleet service engine had the oil pump been replaced at some point!

  15. #14
    N0DIH's Avatar
    N0DIH is offline Cadillac Owners Master
    Automobile(s): 94 Fleetwood Brougham
    Join Date
    Aug 2004
    Location
    Rockford, IL
    Age
    47
    Posts
    7,512

    Re: 5.7 lt1 VS. FORD 4.6 which is more durable

    Hmmm, maybe I should drop the pan and put in a fresh oil pump. I have heard a BBC oil pump is a worthy upgrade (10 vane vs 6) and much improved oiling.

    I really just want to save my $$ and drop in a 6.0L truck LS1....

  16. #15
    JTraik is offline Cadillac Owners Enthusiast
    Automobile(s): '68 DeVille '95 FWB '99 Eldo '96 Cummins Ram 5MT
    Join Date
    Mar 2004
    Location
    Rochester, NY
    Age
    28
    Posts
    763

    Re: 5.7 lt1 VS. FORD 4.6 which is more durable

    To Fords credit...ahem... my father has a transporation business with several town cars. One was retired a while ago but is still in use is a '98 town car with around 200k, other than tranny problems the car rides and runs like silk. Before that we had the 5.0 lincolns and they ran forever to with proper maintenance. The I prefer a ford 5.0 over their 4.6 for their cast iron construction, cheapness to fix and sheer simplicity. GM small blocks carry my same preference, they are so easy and usually cheap to fix especially gen I's Not to mention they outlast anything given proper care ;-)

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