Concerns to watch for in the 1993 GM Cadillac Allante
#1
01-01-2008, 10:51 AM
Concerns to watch for in the 1993 GM Cadillac Allante
This thread is in NO WAY meant to belittle the 1993 or any other Allante.
I believe it is a good thing to be aware of expected potential or ongoing issues on any car.
This thread is meant to do just that. Not the 1 issue in 1,000 cars, but the most very common
issues for this '93 model.
For those that dont know, every 1993 Allante had the 1st generation NorthStar 4600 engine
and this models are considered PHASE III.
I have tagged the thread .. " FAQ "
Please keep any issues in this thread to those strictly related to the 1993 Cadillac Allante.
Any issues common to all year models, including the '93, please post elsewhere.
ISSUE: Engine misfire, most probable causes: coils, primary wires, PCM
my 93 seems to be running on 7 cylinders, misfires, wants to stall. has 150k mi
what do I look for?
what do I look for?
it was a coil
thanks
My 1993 Allante has an engine miss on a slight grade, high gear, but if it shifts down to the next gear the miss seems to go away.
I have changed the plugs, wires, EGR valve, PC valve. $$$$$$$$ +$$$$$$$ +$$$$$$$$ + $$$$$$$$$$
I have checked the diagnostics, no codes.
What else could I look for?
by Allantesource
the ignition coils if original are the most cause of a miss.
Spark plug wires are the second most common cause. The plugs are platinum and probably are fine. GM recommends a 100,000 mile change interval, but a Northstar powertrain engineer who used to post here said that change interval was arbitrary. They just didn't want to say anything would be good forever, for the life of the car. But the platinum plugs probably would be. I just replaced 4 originals on my '91, and they had about 180k miles on them. I had replaced the front 4 at about 100k miles and just had never gotten to the rear bank. The only reason I changed them was that I decided to replace the original spark plug wires. The rear plugs were still fine.
I really doubt that replacing your spark plugs will have any impact on your problem. You can isolate the problem cylinder through the on-board diagnostics, and then replace the coil. Or you can buy a coil and swap it through all 4 positions until you eliminate the problem one.
Spark plug wires are the second most common cause. The plugs are platinum and probably are fine. GM recommends a 100,000 mile change interval, but a Northstar powertrain engineer who used to post here said that change interval was arbitrary. They just didn't want to say anything would be good forever, for the life of the car. But the platinum plugs probably would be. I just replaced 4 originals on my '91, and they had about 180k miles on them. I had replaced the front 4 at about 100k miles and just had never gotten to the rear bank. The only reason I changed them was that I decided to replace the original spark plug wires. The rear plugs were still fine.
I really doubt that replacing your spark plugs will have any impact on your problem. You can isolate the problem cylinder through the on-board diagnostics, and then replace the coil. Or you can buy a coil and swap it through all 4 positions until you eliminate the problem one.
By Allantesource
In addition to the coils, '93 PCM's are also a real weak spot.
I have not seen an original still in place in years. Apparently most have needed replacement over the years.
I have not seen an original still in place in years. Apparently most have needed replacement over the years.
to get to Dick, CLICK here:
ALLANTESOURCE
#2
01-01-2008, 11:06 AM
RE: Concerns to watch for in the 1993 GM Cadillac Allante
'93 unique topics
- engine misfire
- plenum failure
- flying soft tops
- flying boot covers
- headbolts
- struts
- transmission
- overheating
- ???
.. to come ...
- engine misfire
- plenum failure
- flying soft tops
- flying boot covers
- headbolts
- struts
- transmission
- overheating
- ???
.. to come ...
#4
01-03-2008, 12:39 PM
RE: Concerns to watch for in the 1993 GM Cadillac Allante
Luckily the PCMs can easily be found - they were on a lot of Caddys, and I believe even the Aurora - and for not much - I think about $150, and that is from GM.
Heck, give me my old Northstar over the 4100 hook and tow any day - and even the 4500 has its share of problems.
I think one of the best parts of the Northstar is that a lot of the parts are still available - new - from GM - they put that power plant in so many cars.
It can't be such a bad engine - lots and lots of people race with the Northstar - very few with a 4100 or 4500.
Stealth -I think you are just itching for a fight - and this week, since my Allante is enjoying an extended stay at the Car Spa - there just isn't much bite in this Fox...
Heck, give me my old Northstar over the 4100 hook and tow any day - and even the 4500 has its share of problems.
I think one of the best parts of the Northstar is that a lot of the parts are still available - new - from GM - they put that power plant in so many cars.
It can't be such a bad engine - lots and lots of people race with the Northstar - very few with a 4100 or 4500.
Stealth -I think you are just itching for a fight - and this week, since my Allante is enjoying an extended stay at the Car Spa - there just isn't much bite in this Fox...
#5
01-03-2008, 06:09 PM
RE: Concerns to watch for in the 1993 GM Cadillac Allante
ORIGINAL: Stealth
'93 unique topics
- plenum failure
- flying soft tops
- flying boot covers
- headbolts
- struts
- transmission
- overheating
- oil leaks
- ???
.. to come ...
'93 unique topics
- plenum failure
- flying soft tops
- flying boot covers
- headbolts
- struts
- transmission
- overheating
- oil leaks
- ???
.. to come ...
Hey Fox, this is he way I think of the older crowd with pre 93's.............If I have to explain they won't understand. Having said that, the pre 93's do have some good points too, and they are beautiful cars.
#6
01-04-2008, 03:13 AM
RE: Concerns to watch for in the 1993 GM Cadillac Allante
ISSUE: Northstar Plenum fire and explosion, most probable causes: leaky fuel regulator, original engine cover.
Conclussion; this ailment is only associated with the 1st generation NorthStars, not on subsequent generation Northstars of other Cadillacs.
FYI - for the purpose of this "engine" topic, the Phase II are the 1989 - 1992 Allante 4500 engines,
not to be confused with the hard/soft tops, Phase I, II, III. This topic does affect other Cadillacs but unsure as to what models and mfg dates are affected. I believe this was a GM recall.
Cadillac plenum fire
[IMG]local://upfiles/2893/A38287660C8A452AB5068ED2FD14D3C0.jpg[/IMG]
Conclussion; this ailment is only associated with the 1st generation NorthStars, not on subsequent generation Northstars of other Cadillacs.
FYI - for the purpose of this "engine" topic, the Phase II are the 1989 - 1992 Allante 4500 engines,
not to be confused with the hard/soft tops, Phase I, II, III. This topic does affect other Cadillacs but unsure as to what models and mfg dates are affected. I believe this was a GM recall.
by Allantesource
There is a definite reliability gap between the early Northstars and the 4.5's. Now that GM is not replacing '93 Northstars under warranty, that alone is a real good reason to opt for a Phase 2. The head bolt problem is expensive to fix, not to mention the oil leaks and the plenum issues.
There is a definite reliability gap between the early Northstars and the 4.5's. Now that GM is not replacing '93 Northstars under warranty, that alone is a real good reason to opt for a Phase 2. The head bolt problem is expensive to fix, not to mention the oil leaks and the plenum issues.
by unk
on the cover for a 93, GM offered two designs intake mainifold cover...
- ORIGINAL design used bolts without grommets,
- second design is with grommets
newer design pn 17090937 costing around $210 if avail, shared with other models such as EldO '94
what do the grommets do?
- ORIGINAL design used bolts without grommets,
- second design is with grommets
newer design pn 17090937 costing around $210 if avail, shared with other models such as EldO '94
what do the grommets do?
by Allantesource
With grommets means that there are rubber grommets under the cover retaining bolts that will give if there is an explosion inside the plenum. Without the give of the rubber grommets, in the event of an internal explosion (such as from a leaky fuel pressure regulator) the plenum blows up and has to be replaced. I have no idea if the plenums will accept both covers or not. The only plenum I replaced personally was a later style, and it had been hit and cracked by a piston that went up through the valley. I sold an early plenum to someone who had the explosion in a very early '93 Allante'. But he would have used the cover that came with the one I sold him. You could always pick up a plenum off a '94 Concours, Seville, or Eldorado Northstar. Those are all the grommet style.
by jefft
Wait a minute, EXPLOSION? WHAT EXPLOSION. Every day is a new learning experience.
Just when you thought buying a 93 was a "safe" proposition ol Dick tells us all about the EXPLOSION in the valley! Jeezsch!
Wait a minute, EXPLOSION? WHAT EXPLOSION. Every day is a new learning experience.
Just when you thought buying a 93 was a "safe" proposition ol Dick tells us all about the EXPLOSION in the valley! Jeezsch!
by Allantesource
The plenum issue is explosions in the plenum when the fuel pressure regulator malfunctions and leaks gas which can get ignited. The "fix" was to place rubber grommets under the cover bolts, so if/when there is an explosion, the cover lifts to vent the force generated and the plenum doesn't blow apart. That whole plenum system was redesigned for 1995. Early 1993 Allante's did not have the cover grommets. All were supposed to be modified, but as with every recall, some were missed.
The plenum issue is explosions in the plenum when the fuel pressure regulator malfunctions and leaks gas which can get ignited. The "fix" was to place rubber grommets under the cover bolts, so if/when there is an explosion, the cover lifts to vent the force generated and the plenum doesn't blow apart. That whole plenum system was redesigned for 1995. Early 1993 Allante's did not have the cover grommets. All were supposed to be modified, but as with every recall, some were missed.
by unk
An explosion can be caused by a faulty FPR
An explosion can be caused by a faulty FPR
[IMG]local://upfiles/2893/A38287660C8A452AB5068ED2FD14D3C0.jpg[/IMG]
#7
01-04-2008, 07:43 AM
RE: Concerns to watch for in the 1993 GM Cadillac Allante
Hey, we all joined the same club when we bought any year Allante. I don't believe I have seen any one year or engine signaled out with "less" problems. I've only had "one" major problem with my "87" for instance. The "dreaded" head gasket problem which would have been alleveated if Cadillac had insisted on 24 mo coolant replacement from the go, go. Heck and all I had to do to correct this in my car was replace the engine!
The "brakes!",, heck, that's something all owners should expect and I feel sorry for the owners that don't know of sites "like this" and Allante source. I thought of "upgrading to a "93" because of the brake potential but when I weighed losing the seats and relative simpler systems all around vs getting a lot of power I really didn't have any use for, I decided the money for a hobby didn't warrant it. For a daily driver "maybe."
On the outside the cars are just as attractive. That "northstar" under the hood is pretty impressive but then you probably have all heard of the intake manifolds on the 4.1's and 4.5's being so attractive they've been usedfor "coffee tables."
The "brakes!",, heck, that's something all owners should expect and I feel sorry for the owners that don't know of sites "like this" and Allante source. I thought of "upgrading to a "93" because of the brake potential but when I weighed losing the seats and relative simpler systems all around vs getting a lot of power I really didn't have any use for, I decided the money for a hobby didn't warrant it. For a daily driver "maybe."
On the outside the cars are just as attractive. That "northstar" under the hood is pretty impressive but then you probably have all heard of the intake manifolds on the 4.1's and 4.5's being so attractive they've been usedfor "coffee tables."
#8
01-04-2008, 09:44 AM
RE: Concerns to watch for in the 1993 GM Cadillac Allante
When the ASA (Auto Inc) website has an article on rebuilding engines and the single Cadillac engine they quote.... "Cadillac's 4100 engine has suffered from a series of glitches including overheating, cracks and bottom-end knocking, most stemming from its somewhat unusual design and cooling system requirements." along with only 2 other brand name engines - Chrysler's 2.2-2.5 and Mitsu's 2.6 you know there has to be more then "legend" to the moniker "Hook and Tow"
Article quoted (the bad engines are listed about 1/2 down in the article...)
http://www.asashop.org/autoinc/june99/mech.htm
No Northstar on that list - and I have the late series Northstar - I hopefully won't burst into flames anytime soon...
Article quoted (the bad engines are listed about 1/2 down in the article...)
http://www.asashop.org/autoinc/june99/mech.htm
No Northstar on that list - and I have the late series Northstar - I hopefully won't burst into flames anytime soon...
#9
01-04-2008, 10:32 AM
RE: Concerns to watch for in the 1993 GM Cadillac Allante
ORIGINAL: foxpaws
When the ASA (Auto Inc) website has an article on rebuilding engines and the single Cadillac engine they quote.... "Cadillac's 4100 engine has suffered from a series of glitches including overheating, cracks and bottom-end knocking, most stemming from its somewhat unusual design and cooling system requirements." along with only 2 other brand name engines - Chrysler's 2.2-2.5 and Mitsu's 2.6 you know there has to be more then "legend" to the moniker "Hook and Tow"
Article quoted (the bad engines are listed about 1/2 down in the article...)
http://www.asashop.org/autoinc/june99/mech.htm
No Northstar on that list - and I have the late series Northstar - I hopefully won't burst into flames anytime soon...
When the ASA (Auto Inc) website has an article on rebuilding engines and the single Cadillac engine they quote.... "Cadillac's 4100 engine has suffered from a series of glitches including overheating, cracks and bottom-end knocking, most stemming from its somewhat unusual design and cooling system requirements." along with only 2 other brand name engines - Chrysler's 2.2-2.5 and Mitsu's 2.6 you know there has to be more then "legend" to the moniker "Hook and Tow"
Article quoted (the bad engines are listed about 1/2 down in the article...)
http://www.asashop.org/autoinc/june99/mech.htm
No Northstar on that list - and I have the late series Northstar - I hopefully won't burst into flames anytime soon...
" Repair, Rebuild or Replace? "
http://www.asashop.org/autoinc/june99/mech.htm
keeping THAT title in mind, read on ..
ohh, and BTW, what will the next high power '09 CTS-V and C7 Corvettes probably use ?
by the Engine Rebuilders Association (AERA)
In researching this engine, we discovered that few rebuilders are overhauling Northstar V8s - not because these engines are lasting forever (they're not) but because the Northstar V8s are such expensive and complex engines.
Cadillac has no reman program for Northstar V8s (if one fails, replace it with a new one).
None of the major production engine rebuilders are doing Northstar V8s, and some rebuilders told us certain critical internal parts are unavailable (such as oversize crankshaft bearings).
Add to this the fact that the cylinder liners can't be replaced or overbored and it doesn't leave much to rebuild.
In researching this engine, we discovered that few rebuilders are overhauling Northstar V8s - not because these engines are lasting forever (they're not) but because the Northstar V8s are such expensive and complex engines.
Cadillac has no reman program for Northstar V8s (if one fails, replace it with a new one).
None of the major production engine rebuilders are doing Northstar V8s, and some rebuilders told us certain critical internal parts are unavailable (such as oversize crankshaft bearings).
Add to this the fact that the cylinder liners can't be replaced or overbored and it doesn't leave much to rebuild.
https://www.cadillacforum.com/m_17336/tm.htm
======================================
my only bubble bursting personal comment to all this Northstar chatter?
I dont believe the N* is an engine that can be economically overhauled and I do believe that
the use of salvage cars and the engines from "wrecked" cars" is an excellent and econo solution,
if you are willing to do your homework ...
IF the need is racing, overhauling/rebuilding the innards of a N* is probably not the answer,
adding accessories like blowers, NOS, and such, or exchanging cams, ignition system, exhaust systems,
filters, etc or changing the timing (performance chips) .. may be .. ask around .. do your homework as
it relates to your specific car and model and version of engine.
IF your need is to drive point A to point B, R&R is probably the viable economical answer for now.
Whether an Allante or any other Cadillac, no matter.
#10
01-04-2008, 12:00 PM
RE: Concerns to watch for in the 1993 GM Cadillac Allante
"B--U--T????? My neighbor in Texas bought a 93 Cad sedan for his wife for "economies" sake. He was impressed with the first car engine that you went 100,000 miles before even replacing the sparkplugs!!
Couldn't answer my question about how difficult it might be removing some spark plugs from an aluminum block engine after it had gone those 100,000 miles!
Couldn't answer my question about how difficult it might be removing some spark plugs from an aluminum block engine after it had gone those 100,000 miles!