The Northstar

[CRC2362]

Hello all I hope this post finds everyone well. I know the subject of the reliability of the Northstar has been discussed to death both in this forum and the internet, so I apologize now for bring the subject up again. Well anyways, I have a '99 Deville with just under 69,000 miles on her and have been very diligent about routine maintenance, Oil change every 3,000 miles, Transmission service (not the one where they hook it up to a machine), cooling system flush every 2-3 years with Dex-Cool, Throttle body cleaning and so on. So far she has been great. I just had her painted at a cost of $5,300 and she looks brand new, all body side moldings were replaced along with all the badges, I'm very pleased. So the point of this post is to find out what percentage of these cars (engines) actually have the head gasket problem. I still see a lot of these cars on the road and have read a lot of posts where people have 100,000 and even 200,000 miles on their cars. My vin # isn't in that group of engines that had the head gasket holes drilled too deep, which I'm happy about. So does anyone have information, opinions or is my '99 doomed and it's just a matter of time? Craig

[Cadillac Jim]

There's a poll topic on that. here's the board where the poll is:

http://caddyinfo.ipbhost.com/index.php?showtopic=4942

It's at about 15% of the total. My observation is that head gasket problems are rare under 100,000 miles, and that nearly all of them can be traced to letting the coolant go over 5 years (red) or two years (green).

[BodybyFisher]

My opinion has recently changed on this topic. My coolant was changed often and my head gaskets recently blew, I am sure I will find pulled bolts. It could be that the head gaskets eventually deteriorated, thermal expansion, overheating that crushes the head gasket allowing coolant to get to the bolt holes, stress, etc.

I hate to say this, but I belive that for the 96 - 99 engines, its just a matter of time, mind went at about 120K.

I dont think its coolant change related, I think the bolts eventually just pull out of the block

Sorry if this sounds harsh, here is an article

http://www.aa1car.com/library/2005/ic010532.htm

[Texas Jim]

Hello all I hope this post finds everyone well. I know the subject of the reliability of the Northstar has been discussed to death both in this forum and the internet, so I apologize now for bring the subject up again. Well anyways, I have a '99 Deville with just under 69,000 miles on her and have been very diligent about routine maintenance, Oil change every 3,000 miles, Transmission service (not the one where they hook it up to a machine), cooling system flush every 2-3 years with Dex-Cool, Throttle body cleaning and so on. So far she has been great. I just had her painted at a cost of $5,300 and she looks brand new, all body side moldings were replaced along with all the badges, I'm very pleased. So the point of this post is to find out what percentage of these cars (engines) actually have the head gasket problem. I still see a lot of these cars on the road and have read a lot of posts where people have 100,000 and even 200,000 miles on their cars. My vin # isn't in that group of engines that had the head gasket holes drilled too deep, which I'm happy about. So does anyone have information, opinions or is my '99 doomed and it's just a matter of time? Craig

Craig,

At this point, considering how you have maintained your car, I wouldn't worry about it TOO MUCH.

I get the impression that you plan on keeping the car, or you wouldn't have had it repainted and replaced the body side molding and all badges.

There is a technique that uses STUDS to repair the Northstar if or when they blow the gaskets.

After this is done, the engine is stronger than when it was new.

Maybe this is something you want to check into...for the future..."IF" you ever need it.

Some of the Northstars seem to run forever, and some of them eventually need gaskets.

[OynxSTS]

I hate to say this, but I believe that for the 96 - 99 engines, its just a matter of time, mind went at about 120K.

I dont think its coolant change related, I think the bolts eventually just pull out of the block

I have to agree too... I know of WAY too many people who knew about this issue and changed their orange coolant every 18-24 months and STILL had the head bolts fail. This is either a block casting problem or a head bolt design problem, or both.

I still change my coolant every 24 months, and check it monthly, on the hopes that it will buy some time... but I'm not kidding myself that this is a fix to this problem.

Does the NorthStar have a future? Sadly no... GM will pull the plug on this motor sometime next year when the XTS replaces both the DTS and the STS... The new XTS will not come in the first year with a V8 option at all and if in subsequent model years a V8 comes it will be based, like all the others, on the LS family of engines. Dark days are on the horizon for lovers of 32V motors.

[Cadillac Jim]

I don't think that an issue that appears in some motors at 100,000++ miles is a problem, I think that's a maintenance issue peculiar to some motors. I had the intake manifold go on my wife's 3.4 1999 model year 3.4 liter GM V6, causing a coolant loss that would have eventually resulted in coolant in the oil and engine damage (we caught it sooner than that), and indeed her coolant had gone 7 years without a warning from either the Pontiac or Cadillac dealers, who had done oil changes on her car. Even in 2009, aspersions to similar head gasket maintenance issues on post-2000 Nothstars is premature.

Nothing lasts forever, and the Northstar V8 as we know it has gone through four generations and several versions now. We once had the "shortstar" V6 that was replaced by a pushrod V6 that performed better for the same cost/size/weight, and that's been replaced by another all-aluminum DOHC V6, the GM 3.6 liter which comes in DFI and direct injection versions, and has demonstrated durability suitable for twin turbos in aftermarket and special edition vehicles.

The "high value" V8 development has been canceled (along with the V16), and I don't know what, if anything, has taken its place. At this point, I think that the 3.6 liter DI V6 is the successor to the Northstar because it delivers similar performance at lighter weight, lower cost, and better fuel economy. This engine appears on the CTS, which is similarly sized to the 1992-1997 Seville, another indication that this engine is the current successor to the Northstar in similar cars.

The current niches for the Nortstar are the larger cars such as the DTS and, in 4.2 liter supercharged form, the smaller V-series such as the STS-V and XLR-V, both of which are at the end of their production runs. If the LS or another engine replaces the Northstar in the DTS, it will be because it provides less cost, lighter weight, better performing, and better fuel economy. When the LS was on the drawing board, people considered lessons-learned from the SBC, BBC, ZR-1 Lotus-designed DOHC V8, and Northstar; an Northstar-equipped Corvette has been doing well in SCCA racing in Europe for some time now (see http://www.chrfab.com/projects.htm and scroll down, or do a web search on "Tom Classon Corvette"). The Plan A configuration was OHV 3-valve, but a 2-valve configuration was found to perform as well and became the LS baseline. Whatever does replace the Northstar, it will weigh less than 350 lbs dry, produce over 300 hp, and provide 20+ mpg overall in a 3800-lb car with an automatic transmission. Personally I don't care what it is. My personal favorite engine configuration is horizontal opposed (boxster) 4-valve VVT with dry sump, with about 500 cc per cylinder. If somebody does better than that, so be it, let the good times roll.

If you have a 1993-1999 Northstar and figure on driving it well beyond 100,000 miles, as I do even now at 140,000+ miles (20K on my exchange engine), then get your ducks in a row to deal with maintenance issues on ultra-high-mileage cars of your type -- all of them. If you do the head gaskets, consider MLS head gaskets (or do a technology survey when the time comes), look at options (Timesert, studs, DIY, mechanic, machine shop, sending it to Northstar Performance for studs, remanufactured or exchange engine, etc.; I got a Jasper after checking here at Caddyinfo). Other issues with 10+ year old Northstars include case-half O-ring seepage so you should consider replacing the O-ring when you do the head gaskets.

There is no fundamental problem with any Northstar. Browse around Cadillac Hot Rod Fabricators for a look at your choice of intake (choice of superchargers, twin turbo, carburetor, stock DFI with new ECM or custom DFI) and up to 600 hp with the stock bottom end and more for more $$$.

[joeb]

32V motors are dinosaurs? no way. i mean to say 4 valve dual over head cam motors are the motor of the future. VVT and direct injection is also going to be standard. now the V8 motor might be gone. just a little too much displacement. i think 3.5 litre size is pretty good. thats good for 300-350 easy hp. or a supercharged 4cyl version might also be popular.

[Bruce Nunnally]

Cadillac has a perfectly great 4-valve per cylinder 304 hp engine in the LLT DI VVT V6. Matched to the new 6 speed transmission it moves right along and has good fuel economy.

It's not a Northstar, but sure does the job.

[OynxSTS]

32V motors are dinosaurs? no way. i mean to say 4 valve dual over head cam motors are the motor of the future. VVT and direct injection is also going to be standard. now the V8 motor might be gone. just a little too much displacement. i think 3.5 litre size is pretty good. thats good for 300-350 easy hp. or a supercharged 4cyl version might also be popular.

At GM they are... The 32V replacement for the NorthStar, the ultra V8 was killed over a year ago now. When the NorthStar is retired next spring... it will be the last 32V V8 that GM builds for a very long time, perhaps forever.

[Texas Jim]

Cadillac has a perfectly great 4-valve per cylinder 304 hp engine in the LLT DI VVT V6. Matched to the new 6 speed transmission it moves right along and has good fuel economy.

It's not a Northstar, but sure does the job.

I have "GOT" to go drive one.

I haven't done that...yet.

I drove a CTS for a loaner for a couple of days...but it was the regular 3.6...not the "DI" version.

[JimD]

I have "GOT" to go drive one.

I haven't done that...yet.

Myself.

But I will try to wait for the CTS Coupe.

[Cadillac Jim]

The LS design process has shown that when you are talking over 500 hp, you get more hp per dollar with a pushrod engine. The GM 3.6 liter DI V6 shows that you get a better design (cost, weight, economy) with 4 valves per cylinder. GM has been making DOHC 4-valve engines for daily drivers since the Quad 4 came out in 1988 so they have the formula as well as anyone. I expect that we will be seeing 4-valve engines for a long time.

[OynxSTS]

GM has been making DOHC 4-valve engines for daily drivers since the Quad 4 came out in 1988 so they have the formula as well as anyone. I expect that we will be seeing 4-valve engines for a long time.

Sadly the Quad 4 was another example of a head gasket/head bolt failure just waiting to happen. Most of those engines died before 80,000 miles.

Yes, GM will continue to make DOHC engines for a long time..

But 32V V8 versions on the other hand.... next year will probably be the last for the 32V motors... if not next year, 2011 definately will be...

For anyone who wants a GM DOHC motor, 24V's will be the best that they can do.

[dmk9561]

But 32V V8 versions on the other hand.... next year will probably be the last for the 32V motors... if not next year, 2011 definately will be...

Duramax...

[Bruce Nunnally]

I am more about the results than the configuration. Given a choice I would prefer to have a 430 hp V8 than a 270 hp V8, even if the 430 HP V8 were OHV and the 270hp engine were DOHC.

Also, the attraction to more cylinders is that higher cylinder engines tend to make more torque lower in the RPM band. So V8s traditionally made more torque than V6s than V4s. Again, I would prefer a V6 engine that makes more torque to a V8 that makes less torque (I would REALLY prefer a V16 that makes a ton of torque, but can't always have our cake and eat it too).

[Cadillac Jim]

the attraction to more cylinders is that higher cylinder engines tend to make more torque lower in the RPM band

That's why I said that my preferred configuration would have about 500 cc per cylinder, leaving the number of cylinders proportional to the displacement (and horsepower). That cylinder size gives a good compromise between torque and RPM potential, and specific output (hp per cc) increases with maximum RPM. For a street-only car with automatic transmission, you might want more cc per cylinder. For a race-only engine you would definitely want less cc per cylinder. The V-series Northstars have 550 cc per cylinder and ours have 575 cc per cylinder.

The best fuel economy for a given engine displacement comes from four-valve configurations because they breathe better and are more efficient. Yes, EGR reverses the fact that a four-valve engine leaves less burnt fuel and more new fuel charge per revolution, but with a four-valve engine you have better control of what you need to do to control maximum combustion temperature, which is what EGR is all about, so you will have better results in the real world with four-valve engines, as well as better emissions control. Thus I believe that the state of the art for the foreseeable future is four-valve (with variations such as three-valve and five-valve) with DFI and VVT.

I don't expect to see boxster engines in street cars because they are too wide to put where they would interfere with advantageous front suspension links, or even rear suspension links, particular the DOHC configurations. They are best in rear-engine or mid-engine configurations where they can be put in front of the rear wheels, and in cars where the loss of passenger or cargo space isn't important. Thus the ideal engine configuration becomes the V-block motor, which has the advantage that it doesn't really need a dry sump oil system.

This gets us to the GM 3.6 liter DI V6 for the normally aspirated 300 hp motor.

[Bruce Nunnally]

I still think the 3.6L should be putting out around 330-335 hp btw. Based on the gains seen once a CAI and Sport exhaust system are added, Cadillac is not getting all the power out of this engine that they could. I suspect somewhere the CTS was 'specified' to need a 300 hp engine, and when Powertrain got to 300 they stopped worrying about more power and concentrated on noise, vibration, and harshness (NVH).

[Cadillac Jim]

There's another reason to keep the specific output lower than one might want it to be: torque off-idle to provide throttle response and driveability without a high stall rate torque converter. Driving a car with a high stall rate converter around town at low speeds means wide RPM swings and low fuel economy. You can compensate for lack of off-idle torque with a large numerical gear ratio, one reason that we have started to see six and seven gears in automatic transmissions in modern cars instead of the traditional four. I would think that this is not as satisfactory to most people as a more gutsy engine with a four-speed transmission. One option is to have separate engine tuning for a standard shift model and this was once common, but driving a standard shift with an engine with low off-idle torque is a skill beyond what most people expect, even those who drive standard-shift cars, unless, again, a high ratio low gear is used, which requires a quick shift to second gear on startup, which I would find aggravating. Perhaps with CVT we will have yet another traditional issue go away with technology; this awaits CVT designs that are as efficient, reliable, inexpensive, and handle the horsepower as existing transmissions.

With VVT, it would seem that a way might be found to get higher specific output from the 3.6 DI engine, by varying the angle between the intake and exhaust lobes as well as moving the timing of the valve openings earlier at higher RPM.

Note that GM has a long history of not extracting the most from their high-performance engines in early production, and even then underrating the advertised outputs. In some cases, the Northstar among them, the potential is never really tapped, unless you consider teh 4.2 liter supercharged versions used in the V-series -- and even then one of them was tuned for lower horsepower for reasons that totally escape me.

[OynxSTS]

I still think the 3.6L should be putting out around 330-335 hp btw. Based on the gains seen once a CAI and Sport exhaust system are added, Cadillac is not getting all the power out of this engine that they could. I suspect somewhere the CTS was 'specified' to need a 300 hp engine, and when Powertrain got to 300 they stopped worrying about more power and concentrated on noise, vibration, and harshness (NVH).

To add to that the pending death of the 32V V8 at Cadillac... I would say that not only is Cadillac not getting all the power out of the 3.6L engine that they could... the complete future lack of a 450-500 HP 32V motor to go head to head with the best from Germany will SEVERELY limit the competitiveness and the product development at our favourite GM division...

If I had to point to one of the biggest mistakes make by Rick Wagoner and Bob Lutz it was the cancellation of a V8 replacement for the NorthStar. This terrible decision will have serious repercussions for years to come.

[PAUL T]

My 94 Concours Northstar went at 166,000 miles. I denied it for a long time but eventually had to accept it.

[Cadillac Jim]

I put in a reman at 116,500 miles and plan to drive the car several more years. I've had it 12+ years now. The most I had other cars was 7 years (the 1959 Chevrolet 235 cid 6 and the 427 cid Cheverolet wagon). The 1959 had three engines and the wagon had two. I'm way ahead with the Cadillac.

[dmk9561]

Another reason to prefer a V8 (or more) in a luxury car is the smoothness, both a lack of vibration and a soften the pulses of the exhaust noise. Back in the days of the V16, lots of makes had a V12, because they were easier to balance. Everything is built to a price and purpose, and the Northstar had many objectives when it debuted, and the primary one was to steal Lexus' thunder. The LS400 debuted in 1990 with a 250hp 4.0l DOHC V8 when that sounded downright exotic. The dowdy, indifferently-assembled Cadillac models with their impotent 4.9 OHV and 185hp weren't in the same league. The Lexus was better than a Mercedes and cheaper, too, but Cadillac wasn't. The '92 Seville was surely meant to debut with the Northstar and instead it was delayed one year. Compare the '93 STS overall to the '91 and it's crystal clear what was going on, and I feel it was pretty successful. In fact, the initial Northstar's swaggering exhaust note so put off buyers that it was tamed one year in. Its power and advertising were as subtle as a concrete block thrown from an overpass.

Sadly, it took 10 more years for the Northstar to progress much, and it took a RWD platform. More than 300hp was probably thought dangerous in FWD settings and too much for the 4T80E anyway. While the '93 Seville was a revelation, the '98 was not. By 2004, it badly needed replacing, and the RWD one was appropriate and as fabulous looking as the '93 had been. Cadillac's lineup today is better than it's ever been.

I agree with the above statements that canceling the Northstar's replacement (suggested name: Northway) was a big mistake. The LS is a fantastic engine in its own right, but it's much too famously Chevrolet to see good acceptance in mainstream Cadillac models. Luxury buyers are fickle. If any part of a Cadillac is seen as technically deficient, the buyers will stay away for that reason. The 3.6 is an excellent engine, and any V8 has its work cut out besting it in any way. That optional engine is an important step-up in luxury buyers' minds. Witness the premium that Mercedes and BMW charge for V8s over the same model with 6. Luxury cars are not about adequate, and the 3.6's competence is not the big deal as much as any V8's superiority.

Cadillac will need V8s through their lineup to compete, not just in its cheeky European foray, but increasingly in the US, too. A clean turbo diesel will be vital in the next 5 years, too. Cadillac can't rest on its laurel and sell only to people who want Cadillacs, but cater to all lux buyers. They've seemed to know that for the past few years, but they also can't afford to ignore it for ANY length of time. The one-two punch of the V8-6-4 and early HT4100 would not be survivable today.

[Cadillac Jim]

Note that the BMW M3 has a V8. Roger Smith is long gone so you can forget airy thought at the top leading to things like the 368 cid V8-6-4 or a 4.1 liter engine in a 5,000 pound car. I agree that Northstar has another generation in it to cover where the High Value V8 would have taken over. Some of the thinking that I was seeing in the High Value V8 was modular thinking, like the Ford Modular V6-V8 family where the same factory builds engines based on castings for V6 and V8 engines that share many parts such as pistons, rods, valves, timing chains and sprockets, dampers, flex plates, etc. and the 3.6 liter DI V6 seemed like it might be the first of the line, or at least a precursor like the Quad 4 was a precursor of the Northstar, which took its timing chain concept but not its 80 hp/liter specific output in HO trim, which would have given it 365 hp. In a FWD, the problems that we have with the exhaust manifolds and crossover pipe don't exist and it seems likely that a 360+ normally aspirated Northstar could be cobbled together using Quad 4 HO cam profiles and a returned intake manifold and exhaust. A fresh look at DI with VVT and the FWD configuration should give an easy 400 hp for a normally aspirated 4.6 liter V8 using the existing Northstar except for the heads, intake manifold, and exhaust system back through the cat. That would give them the three years that they need for a new V8, or to combine the V6 and V8 factories.

Wouldn't you rather see a Northstar V10 in the Escalade rather than an LS? That could provide 600 hp, normally aspirated, and *that* would be a 350 to remember. It would very likely beat the 6.2 liter (378 cid) LS for fuel economy and, with a 6-speed, for driveability. Put *that* in your hybrid configuration.

[Jan Olsson]

Many testers feel that the Cadillac V6 isn't as smooth as the competitors V6 engines, then they test the Northstar engine

Personally I feel that a 90° V8 that can be fully counter balanced with respect to the 1:st AND 2:nd order of vibrations always will be superior to a V6 who in many cases need to be counter-balanced for a smooth run.

Nothing wrong with the current V6 but a V8 should be offered for those who wants the "little extra"..after all Cadillac is a luxury car maker. A V8 based on the technology used in the V6 should be nice.

Everyone is making a V6, Cadillac on the other hand have had V8 engines since 1915. A V8 on the other hand will always sell on the luxury market. It isn't all about top horsepower, it is also about available torque at any rpm.

Admit that it is a certain feeling in having a V8 engine that performs just as well as many screaming twin turbo engines. I am not a fan of technique for its own sake.

Less heat, lesser parts, better feeling.

They should at least offer Northstar engines in the future to fill the gap between the V6 and the V-models.

[BodybyFisher]

Many testers feel that the Cadillac V6 isn't as smooth as the competitors V6 engines, then they test the Northstar engine

Personally I feel that a 90° V8 that can be fully counter balanced with respect to the 1:st AND 2:nd order of vibrations always will be superior to a V6 who in many cases need to be counter-balanced for a smooth run.

Nothing wrong with the current V6 but a V8 should be offered for those who wants the "little extra"..after all Cadillac is a luxury car maker. A V8 based on the technology used in the V6 should be nice.

Everyone is making a V6, Cadillac on the other hand have had V8 engines since 1915. A V8 on the other hand will always sell on the luxury market. It isn't all about top horsepower, it is also about available torque at any rpm.

Admit that it is a certain feeling in having a V8 engine that performs just as well as many screaming twin turbo engines. I am not a fan of technique for its own sake.

Less heat, lesser parts, better feeling.

They should at least offer Northstar engines in the future to fill the gap between the V6 and the V-models.

Hear hear!, I congratulate you