: Biggest Problems with the N*'s?



I~LUV~Caddys8792
01-09-06, 08:03 PM
The Northstar has really intrigued me, I would love to have a DOHC 32 Valve V8 in an american luxury car. I could get either a Northstar or Ford's 4.6 intech V8 in the Mark VIII/ Continental. But I would like to know what the biggest problems on the N* are, and what I have to look out for. I know they are pretty high maintenace, but so is my 4.9 (to an extent) and they consume a lot of oil, and the older ones have an oil burning problem. And I heard something bad dealing with headbolts or something like that I dont remember.

Thanks guys!

danbuc
01-09-06, 09:31 PM
On the contrary...the Northstar is relatively low maintenance compaired to what's out there. As long as you take care of it (i.e. coolant flush when needed, new plugs and wire every 80-90k miles or so,..ect) it shoudl lata very long time, with little or no reliability issues. Of course, there is always the off chance that the headgasket could go on you, but it can be fixed. All N*'s tend to burn a little oil, but they are a performance oriented engine, so it shoudl be excpected. Most of the time, it's from blowby frmo carboned up rings, which can be remedied by a few WOT's. I wouldn't worry too much, as long as the car your looking at has record of maintenace and upkeep, showing that it was cared for. Without that, it could be a gamble, but that goes for any car.

I~LUV~Caddys8792
01-09-06, 09:38 PM
Oh you dont have to worry about me having a N* and not doing enough WOT's ;)

Ranger
01-09-06, 10:35 PM
Oil consumption used to mean worn rings meaning the engine is at the end of it's life or in need of an overhaul. Not so with the Northstar. Read up. Once you understand it, you won't consider it a problem.
http://www.cadillacforums.com/cadillac-tech.html#noil

I~LUV~Caddys8792
01-09-06, 11:39 PM
Oil and carbon gets in the cylinders and will spell the end for the N*, Unless you WOT it! :D

Ranger
01-09-06, 11:49 PM
Neither oil nor carbon in the cylinder will be lethal to the Northstar. Carbon build up on the heads will just lead to cold carbon rap. Annoying but not lethal.

I~LUV~Caddys8792
01-10-06, 12:29 AM
hmmm i have been misinformed......

eldorado1
01-10-06, 12:32 AM
Unless you WOT it! :D

w00t.:banana:

:yeah:

jadcock
01-10-06, 12:00 PM
An acquaintenace with a Mercury Maurader said the same advice goes for the Ford 4.6L V8. Run it hard, or carbon will build up and you'll burn oil...it's not unique to the Northstar...that goes for any 32 valve high performance engine.

The Northstar is an incredibly low maintenance engine. Mine has 149k on it and the only major work has been an alternator and water pump. I just did the plugs for the first time this weekend. The wires were replaced 10k miles ago. Incredibly low maintenance for such an incredible powerplant.

tkarlstad
01-10-06, 04:01 PM
Call me a novice or just my mind not catching on.... what does WOT stand for?

mcowden
01-10-06, 04:18 PM
Call me a novice or just my mind not catching on.... what does WOT stand for?

Wide Open Throttle. Pedal to the floor. The GoFast setting. :D

ghser7
01-10-06, 04:20 PM
Wide Open Throttle

tkarlstad
01-10-06, 05:18 PM
Wide Open Throttle. Pedal to the floor. The GoFast setting. :D
Ok, thank you, now I feel dumb. hehe

I~LUV~Caddys8792
01-11-06, 05:41 PM
So overall the Northstar is a better performing, more reliable motor than the 4.6 Intech?

eldorado1
01-11-06, 07:36 PM
I doubt few of us have experience in both engines. IIRC, the ford 4.6 only has 3 valves per cylinder, we have 4. :D

I~LUV~Caddys8792
01-11-06, 08:49 PM
The 4.6 in the trucks has 3 valves per cylinder

but the 4.6 Intech cobra motor used in the VIII's/Continentals and Cobras has 32 Valves.

jadcock
01-12-06, 08:54 AM
Ford's InTech 32-valve V8 in the Mark VIIIs Continentals has, well, 32 valves. But it also only has 260 horsepower...at least in the late '90s Continentals. I don't know what the mechanical differences are, but the DOHC 4.6L engine in the Cobra and Mercury Marauder have 302 hp.

As stated, the truck engines have moved to 3 valves...at least the 5.4L Triton V8. I don't know if the 4.6L is still available in the trucks. When it used to be standard, back in the late 1990s, even the truck engines were the standard 2-valve engines like what the Crown Victoria/Town Car had.

I also think the 300 hp 4.6L in the 2005+ GT Mustangs is a 3 valve/cylinder design...this is a different variation from the 302 hp Mustang Cobra engines in the previous generation Mustang.

Gotta love those modular engines.

I~LUV~Caddys8792
01-12-06, 06:22 PM
I wonder why the Continental's transverse Intech V8 only has 260hp then 275 in 1998, and the Mark VIII's same motor in longitudinal configuration has 280-290...

Is it because they have to do a different intake setup and possibly more restrictive exhaust in the Conti?

jadcock
01-14-06, 10:47 PM
The transferse FWD layout of the Continental probably does provide a bit more restriction than the layout in the Mark VIII.

For what it's worth, I have compiled a maintenance/repair record of my 1997 Seville since 2000, when it came into the family (was purchased from a Cadillac employee). You can see it here:

http://www.jnjhome.net/cadillac/maint.htm

In a nutshell, I've had to budget on average about $35 a month for "repairs" (things like water pumps, fuel pressure regulator seals, etc), $16 a month on "maintenance" (things like brakes and tires), and $10 a month on modifications (things I've done on my own, like add the CD changer, a Heritage of Ownership medallion, etc). There are a few items that you could argue are maintenance vs. a repair, or vice versa, but I had to make that call. In addition, many of the repairs made in the earlier years were done when my mother owned the car, and done at Cadillac dealers. The prices there throw off the "curve" so to speak, as I'd have done that work myself and saved the labor.

Keep in mind, this takes care of the WHOLE CAR, not just the engine. So overall, I think it's a very economical platform to own.

Playdrv4me
01-15-06, 06:46 PM
The biggest single problem you will find with a Northstar is the crank-case half seal leak. This is something Ive come to learn only very recently and its a little bit of an engineering blunder, but Ive been told by former Cadillac techs that this problem is so bad, they see 1 in 20 GOOD engines.... GOOD, not BAD. In other words, only 1 in 20 engines, from low to high mileages (anywhere from 5-105k here in FL) that comes through the service bay does NOT have the case half seal leakage problem.

Now Im still a little bit in the dark on this, but from everything Ive gathered, this problem is only of concern in relation to safety and oil usage. The thinking being that if oil ends up in the wrong place, things can go poof, and of course you have to add oil more frequently if your losing some.

Other than this the biggest issue seems to be headgaskets and really nothing else of consequence. Unfortunately, after 135000 trouble free miles with a Continental, I can not as of yet consider the Northstar more reliable than the Ford motor. You guys have heard me say numerous times that myself and my brother beat the living piss out of the Ford motor on that Continental and it never once overheated or otherwise did anything of concern. FINALLY, at 120k miles the thing just wouldnt start anymore, and we thought it was fried or we had broken the teeth inside the engine for the starter. Turns out it needed plugs and wires. Go figure...

jadcock
01-15-06, 10:58 PM
Fortunately, for the owner, the case half leak will never develop into anything other than a spot of oil on the garage floor overnight. Fortunately, for the dealer, any oil leak is misconstrued as a disaster and necessary fix. $1500 later, and both are happy. A win-win situation?

The case half leak is a non-pressurized leak that will only expell one or two drips overnight. That's it. Anything more, and it's probably something else. The "case half leak" is so often mis-diagnosed that it's developed a big head of its own that it really doesn't deserve. There are many possible causes of an external leak...the case half is one...the oil pan is another...the cam covers are another...so is the oil filter adapter. So often we've heard of someone who got a big repair estimate from the dealer and the real cause was an o-ring on the oil cooler lines.

You are correct that the case half leak, if you have it, is really only a cosmetic concern. You won't lose enough oil to notice on the dipstick probably. A healthy Northstar will use a quart every few thousand miles, and a drip or two overnight won't really affect that.

Both the Ford and Cadillac engines are good engines. We had a 2-valve version of the Ford engine in a '92 Crown Vic. Good piece. It developed the common valve seal problem at 100k and mom traded it (on the Cadillac actually). I understand Ford fixed the valve seals in the mid 1990s. My Northstar just got its original plugs swapped out for new (at 149k miles). The wires were done about 10k miles ago. It still ran great, but with 49k more than the "recommended" service life, I knew they were due for replacement.