Where did it go wrong: Cadillac's Northstar

"LJ909" (lj909)
09/07/2017 at 18:31 • Filed to: Cadillac, Northstar V8

What was supposed to be an advanced V8 engine to take on the Europeans and Japanese towards the end of the 80's ended up being an expensive to repair problem for a lot of people (including my cousin and his STS). Where did it go wrong?

GM started the development of what would be come the Northstar engine family back in 84 in anticipation of the coming onslaught of German and Japanese luxury sedans that would change the game at the end of the 80's. Its development coincided with some sophisticated stuff coming from Cadillac to combat the foreign brands such as the Allante, Eldorado and Seville. All these models were going to come with advanced features. The Northstar was supposed to be a centerpiece for some of these models.

When all was said and done the engine was originally 4.4 liters and was capable of pushing out 300 horses and featured some advanced designs and features that would ultimately prove to be a headache for many owners years later. From Wikipedia: GM specified cast-iron cylinder liners and the cast aluminum pistons included valve clearance. Northstar is an interference engine, the valves will strike the pistons if they lose timing. It has bronze piston pin bushings and free-floating piston pins. GM used cast aluminum cylinder heads featuring 4 valves per cylinder. The heads used dual overhead cams driven through the “maintenance-free” cam-drive chain case. The cams act directly on hydraulic lifters on the ends of the valves and are fed with a lubrication passage drilled through the cylinder head lengthwise. The intake valves are inclined at 25°, while the exhaust valves are canted to 7° with center-mounted platinum-tipped spark plugs. The cam covers are magnesium for light weight and sound damping.

The engine ended up being a cornerstone of Cadillac. It was introduced in the 93 Allante, which we all know came too late for the model and probably would have helped it had it been introduced with it in the first place.

The introduction of the Northstar on the Allante (and eventually made its way to the 93' Seville and Eldorado) also introduced what was called the Northstar System, which was a performance package. It came with:

Heavy Duty 4 speed auto

Road Sensing adaptive suspension

4 Wheel anitlock disc brakes

Magnasteer variable power steering

Throughout its run the Northstar was a Cadillac only engine. Only until the mid 00's did GM give the engine to other models with it being used in the performance model Pontiac Bonneville GXP and in both the Buick Lucerne Super and the regular Lucerne V8.

Oldsmobile got a variant of the Northstar called the L47 internally. It was used in only the Aurora from 95-99 and them from 01-03 on the second gen. It was 4.0 liters and pushed out 250 horses which I always found a bit low, especially considering the same power could be had from supercharged 3800's from the same year.

Another Olds variant was the “Shortstar”V6 used in the Intrigue and base Aurora. Called the LX5 internally, it pushed out a measly 215 horses. It was never used in anything else and ceased to exist when Olds went to the great dealership in the sky.

The Northstar eventually grew to be a family of different engine variants. Along with the 2 Olds variants listed above, there was also:

The origional L37 which was 4.4 liters and 290 horses. It only made 300 in certain performance high output models.

The LD8, which was what the Northstar eventually became putting out 275 horses.

The LH2, which was originally designed for fwd applications. It was modified for awd, specifically SRX, and was only ever used in the STS, SRX and XLR.

The LC3, which was the superchaged version for the STS and XLR V’s. Both were identical, but put out differnt power numbers with weirdly the STS being more powerful.

Allegedly there was supposed to be a V12 Northstar for use in the Escalade back in 03', but sadly it never saw the light of day. An Ultra engine was also being developed to replace the Northstar, but it was canceled right before the BK. Rumor has it that the gorgeous Elmiraj concept from 2013 is powered by a variant of this Ultra engine.

So where did this sophisticated engine go wrong? Well from years of it being into production, problems are well known, widespread and easy to find out, and it mostly looks like quality problems. Combine that with how sophisticated GM designed the engine and they can prove to be costly, almost German like in their repair costs. Everything from head gaskets, which are to believed to be a problem on all the 4.6's, to crank sensors, 98-04 Seville’s vibrate 65-75 mph, motor mounts are a universally issue, the list goes on and on.

I always liked this engine and thought that if GM hadn’t had the quality problems this engine would probably still be around today. If the Japanese or Germans had done it it still would be. So where do you guys think it went wrong, either from experience or what you know?

DISCUSSION (53)

HammerheadFistpunch > LJ909
09/07/2017 at 18:35

usually with the rings or headgaskets. but not always.

LJ909 > HammerheadFistpunch
09/07/2017 at 18:36

That was one of the first problems my cousin had with his STS.

HammerheadFistpunch > LJ909
09/07/2017 at 18:38

What GM should have done when they realized they had a high feature engine with problems is sold it to Land Rover. its worked before.

Rusty Vandura - www.tinyurl.com/keepoppo > LJ909
09/07/2017 at 18:48

I read your post and thought immediately about the LT-5 ZR-1 engine from the early 90s, and it turns out that the Northstar has the LT-5 deep in its gene pool.

You mention the supercharged 3800. I’ve heard that that those engines develop intractable problems that are nearly impossible to correct.

Then there was the V8-6-4 ... I’m old enough to remember those.

theloudmouth > LJ909
09/07/2017 at 18:50

What went wrong? It was a GM product that wasn’t engineered before we landed a man on the moon (see: short block).

BaconSandwich is tasty. > LJ909
09/07/2017 at 18:50

I vaguely remember someone swapping one of these into a Fiero...

Maybe it’s just me, but it seems to produce a small amount of power for the displacement.

Discerning > LJ909
09/07/2017 at 18:54

I had a Northstar in a Cadillac Seville STS. Ran hard... when it ran.

But realistically, the Japanese had built something similar earlier.

The Nissan VH45DE was released in 1989 with 278 hp and seriously stout internals. Even the 4.1L that the US got stuck with in the later Q45 had 266 hp.

Not quite as high as the early N*’s but very reliable and underrated.

Of course, the VK that replaced it made pretty respectable power in the 2003 M45: 340 hp.

Then there’s the racing background and connections of both the VH and VK.

I think GM’s biggest mistake was not offering it in a RWD platform sooner and not really campaigning it in any races or anything. It was just “good enough.”

itschrome > LJ909
09/07/2017 at 18:56

Northstar is best star!!

Northstar did nothing wrong

Also, the head issue was a shame but fixed in 01. Also the vibration thing, ehhh. I mean it was a thing but not really yeah the crank sensor could go wrong but it wasnt really that big of an issue. The later run northstars were pretty solid.

LEAVE THE NORTHSTAR ALONE!!!

LJ909 > Rusty Vandura - www.tinyurl.com/keepoppo
09/07/2017 at 18:57

With the performance that the LT-5 had I’m not surprised that it was closely related to the Northstar. Outside of the shitty quality these engines really show what GM can do when they, you know, actually try.

What kind of intractable problems can the 3800 develop? And I’m too young to remember the V8-6-4. I’ve only read about it.

If only EssExTee could be so grossly incandescent > LJ909
09/07/2017 at 18:58

Kinja'd!!!

The Northstar hit its peak with the LMP program. The cars used a twin turbo version of the 4.0 L47 good for 650hp.

A working Northstar V12 actually did get made, but being a 60-degree engine with twin throttle bodies and direct injection, it had nothing in common with the V8s except the name. It made its way into the Cien concept.

Kinja'd!!!

LJ909 > theloudmouth
09/07/2017 at 18:58

The Northstar is based on the Small Block?

LJ909 > BaconSandwich is tasty.
09/07/2017 at 19:03

That seemed to be an 80's Cadillac thing they never shook. You would have something like the Deville, which had the 425. 6.9 damn liters and only 180 horses. If the Northstar was around today it would at least be pushing 450.

Rusty Vandura - www.tinyurl.com/keepoppo > LJ909
09/07/2017 at 19:04

My next door neighbor had one and he dumped it when he couldn’t sort it out. And this guy is a crazy-skilled mechanic, too. I will ask him and get back to you.

merged-5876237249235911857-hrw8uc > LJ909
09/07/2017 at 19:09

Well they went wrong in ditching a perfectly good LS engine family because it wasn’t OHC. Then they couldn’t figure out how to bolt the heads on the N-star so they develop a head gasket leak that requires an engine out repair, very German of them.

LJ909 > If only EssExTee could be so grossly incandescent
09/07/2017 at 19:12

I was a big fan of Cadillac’s LMP program. I just hated that none of that racing success ever found its way onto production models.

Sadly the V12 was just for show, just like a lot of their stuff of late.

LJ909 > Rusty Vandura - www.tinyurl.com/keepoppo
09/07/2017 at 19:14

Thanks I’m really curious.

Mondial goes to 11 > HammerheadFistpunch
09/07/2017 at 19:18

Yeah, the head gaskets always leaked. Except for the one with a cracked head at 3k miles. That’s not missing a zero.

Kiltedpadre > BaconSandwich is tasty.
09/07/2017 at 20:03

For awhile there was a company selling kits for that swap. It was never as popular as swapping in a 3800 because the northstar is large enough to require the engine bay to be modified for it to fit.

Brickman > LJ909
09/07/2017 at 21:03

The Cien was fun in Gran Turismo 4 ;D

theloudmouth > LJ909
09/07/2017 at 21:22

I was being sarcastic, stating GM hasn’t made a truly world beating anything since the small block or before 1969.

Nibbles > Rusty Vandura - www.tinyurl.com/keepoppo
09/07/2017 at 21:27

I’m curious too

Nibbles > BaconSandwich is tasty.
09/07/2017 at 21:31

300 horses out of a designed-in-the-eighties 4.6? When Ford’s engine of the same displacement was putting out 225, and Dodge couldn’t get more than 240 out of a 5.9

By today’s standards, sure. Not a lot of juice when turbo 4 pots are putting out more. By the standards of when it was built and used? That’s a fair amount of juice, my friend

Shift24 > LJ909
09/07/2017 at 22:18

The northstar was GMs atempt to make a new age engine. But they turned out to be ok engines with a major design flaw in crap “luxury” cars that only grandma and grandpa would buy. Thats why it failed. Head gaskets are an issue across the board but they are caused by weak head bolts that start to separate. This creates a bad seal which is normally confused with the bad head gasket.

BaconSandwich is tasty. > Nibbles
09/07/2017 at 22:19

Valid points! I guess I was comparing it to much newer engines.

pip bip - choose Corrour > LJ909
09/08/2017 at 05:43

thankfully it was never offered here.

Dave the car guy , still here > LJ909
09/08/2017 at 07:44

Working in two GM dealerships and one being a Cadillac shop I had a lot of experience with that POS engine. The aluminum was crap and GM should have come up with a real solution. The aftermarket kit for doing head studs to eliminate the bolts solves at least the head gasket issue.

remnokc > LJ909
09/08/2017 at 08:39

same here, I have had 2 Northstars. Seems I read somewhere that they ALL need a head gasket job about 80,000 mi. My ‘93 ETC was having overheating problems which the dealer would not admit until it was out of warenty of course.

The ‘03 DTS I still own has had an easy life and has just started hinting of needing a head job in the last couple of years w/ less than 80thou.

Hammerdown > LJ909
09/08/2017 at 09:50

I thought the GXP’s and Lucerne’s had 5.3 LS motors in them? The LS4 I believe?

Nibbles > BaconSandwich is tasty.
09/08/2017 at 11:33

The problem was they built it to max tolerance. There wasn’t any room to grow from that block. Engineers said it could be bored up to 5.4 theoretically, but not a single successful test was made.

gawdzillla > LJ909
09/08/2017 at 11:42

because it wasnt LS1

should have throw more money into the LS1

The Powershift in Steve's '12 Ford Focus killed it's TCM (under warranty!) > Hammerdown
09/08/2017 at 11:45

The LaCross Super the Grand Prix GXP had the 5.3 - they shared the W-body platform with the 5.3-powered Impala SS.

Hammerdown > The Powershift in Steve's '12 Ford Focus killed it's TCM (under warranty!)
09/08/2017 at 11:53

That’s what I thought. Which conflicts with this:

LJ909 > Hammerdown
09/08/2017 at 12:36

Yea only the big cars got the Northstar and even then it was only used on the Boneville and Lucerne.

Hammerdown > LJ909
09/08/2017 at 13:28

Ahhh that’s right. I remember the Bonne’s getting the Northstar.

ExquisiteMouthFeel > LJ909
09/08/2017 at 14:30

The Northstar had a soul to it. It was like a reserved, but potentially ferocious animal under the hood. My first car was a 98 STS with the L37, I loved it. I was 17 and had 300hp at the disposal of my right foot. It was silky smooth and loved to rev. Around 4k was the sweet spot for that engine’s sound, being one of the few cars I’ve driven where the sound of the engine could truly replace the radio. It really would’ve been a fantastic engine if not for the weak block and high oil consumption (I got 160k out of it before it went to the great engine bay in the sky). It maybe could’ve been America’s version of the Lexus V8 if it had been done right. The 3.6 V6 that replaced it is a great engine, but it just doesn’t feel quite so nice.

CaptDale - is secretly British > LJ909
09/08/2017 at 17:11

Oh god the amount of midblock reseals we do here at the dealership is wild. Though as the cars age and the demographic goes from grandfather, to grandson, to 3rd-5th owners, the job gets less and less common at least at the dealership. It has probably been a year and a half since the last one we did and when I started here 4 years ago we were doing them had over fist.

LJ909 > CaptDale - is secretly British
09/08/2017 at 17:20

Thats crazy. its probably gotten to the point now with the older models that the ones that were done are either holding up or people are doing them themselves. Even then I’m sure you probably see DTS’ and Lucerne’s still coming in. A lot of these problems are what have stopped me from getting an XLR.

CaptDale - is secretly British > LJ909
09/08/2017 at 17:53

No I think these people are just going to indies for it. We used to see some of the same cars come back for a midblock a couple times.

Fuck, yeah if the XLR wasn’t still like $40k then I would buy one and install an LS like it should have had. I wish GM isn’t always worried about losing Corvette sales. Like who fucking cares?! Just build a good car and some people may switch, but I am sure some people would have still bought their Corvette cause Corvette.

LJ909 > CaptDale - is secretly British
09/08/2017 at 18:03

Thats if you can even find one anymore. Within a 100 miles of me there are under 20 for sale. I think like 13. One of em is 15 grand but it has 95 thousand miles.

I agree it should have had an LS. But then there would have been even less of a reason to buy it over the Corvette. It literally would have been a more expensive Vette with a folding metal roof.

415s30 W123TSXWaggoIIIIIIo ( •_•))°) > LJ909
09/08/2017 at 18:12

It went south, should have been named the Southern Cross.

CaptDale - is secretly British > LJ909
09/08/2017 at 18:12

Right but at the time GM was afraid that the XLR because of the folding metal roof would take sales from the Corvette if they gave it Corvette power. Hence the terrible Northstar. Plus I prefer the XLR to the C6 as a design any way.

Car Gurus show 120 for sale across the country ranging from

$12,500 with 153,041 miles

$54,995 with 3,300 miles

Though there is this monstrosity for $89,500 ( Jelopicnic article on it )

Kinja'd!!!

415s30 W123TSXWaggoIIIIIIo ( •_•))°) > CaptDale - is secretly British
09/08/2017 at 18:14

Yeah a Vette isn’t really an on the fence car, you want one if you’re a Vette person.

CaptDale - is secretly British > 415s30 W123TSXWaggoIIIIIIo ( •_•))°)
09/08/2017 at 18:17

Yeah, but that is GM, always worried a performance car from their own brand will take sales away from it.

415s30 W123TSXWaggoIIIIIIo ( •_•))°) > CaptDale - is secretly British
09/08/2017 at 18:19

If they want a Vette but want a cheaper one, they buy a used one. They have an LS so you don’t really have much to worry about.

LJ909 > CaptDale - is secretly British
09/08/2017 at 18:24

I always thought that the XLR was one of the best examples of Cadillac’s Art & Science. It was what I would have imaged a proper GT from Cadillac would look like. The C6 was nothing special, and those clear headlamps looked cheap.

Those things should be blown up and are tacky. Probably about as tacky as the owner who thought they were a good idea.

But 6 of those 120 are within 100 miles of me. The one thats 15 grand has 99 thousand miles. I wouldnt bite. The most expensive is $32,500 for an 06 out in Palm Springs that I’m sure was driven by a retiree.

CaptDale - is secretly British > 415s30 W123TSXWaggoIIIIIIo ( •_•))°)
09/08/2017 at 18:27

Right, but the XLR was a Vette underneath with a hard folding top (at the time a big deal) and branded a Cadillac so boom Northstar with less preformance so it couldn’t compete with each other. Also the XLR was more

CaptDale - is secretly British > LJ909
09/08/2017 at 18:28

I don’t know, if I had the proper opportunity to buy an XLR-V I would.

But I agree, the design of the XLR way outshined the C6 in every way but motor. It is a shame that they didn’t take off more and that the Northstar required a lot of maintenance.

LJ909 > CaptDale - is secretly British
09/08/2017 at 18:38

Yea the Northstar is an unfortunate downside that I dont think I could get around to make me buy one. I’ve never even seen an XLR-V for sale and if I did the owner would probably want more than what he should be asking. STS-V’s go for cheap though. And honestly its the better buy because they had more power than the XLR. The STS-V had 469 compared to the XLR-V’s 443. I never got why they did that.

CaptDale - is secretly British > LJ909
09/08/2017 at 19:00

My only thought on the power difference would be the weight

STS-V curb weight 4,343 lb = 0.108 hp to lb ratio

XLR-V curb weight 3,810 lb = 0.1163 hp to lb ratio

So I mean technically the XLR-V was a better performer than the STS, looks better, and is definitely cooler.

And the STS-V has the same motor and I would much rather have the XLR out of the two. Also

Kinja'd!!!

phewop118 > LJ909
09/08/2017 at 19:21

Having owned 5 cars with Northstars or Northstar-based engines, I can attest to the little typical GM issues. But overall, the have held up fairly well. Highest mileage right in my lineup is the Shortstar in my Intrigue at 195k.

Some have oil leaks, others get carbon buildup if you baby them. But keep the temperature good and run them hard and they will run damn near forever. Not bad upper end power either.

Rusty Vandura - www.tinyurl.com/keepoppo > LJ909
09/19/2017 at 22:38

Head gaskets, he says. In his case, he’d had more than one go south, and this time it was on the rear bank. Add to that, somehow the smog shop fried the engine control module and he deep sixed it. He had one and his son had one and they both required head gaskets.

Rusty Vandura - www.tinyurl.com/keepoppo > Nibbles
09/19/2017 at 22:39

Nibbles > Rusty Vandura - www.tinyurl.com/keepoppo
09/19/2017 at 23:15

Oh geez