The Northstar engine series was a group of high performance V engines produced by General Motors, an American multinational corporation headquartered in Detroit that focuses on the manufacturing, marketing, and distribution of vehicles and vehicle parts, between 1993 and 2011. Originally considered GM’s most complex engine, the double overhead cam and the four valve per cylinder aluminum block engine was most commonly associated with the Northstar series in the Cadillac. The Cadillac was a division of the General Motors Company that designs and features luxury vehicles.
In the basic form of the Northstar engine, the mechanism was designed to displace around 4.6 liters, with the supercharged version being a 4.4-liter engine. Different kinds of Northstar engines were used at Oldsmobile and in several high-class and luxury Pontiacs in the 2000s, making you wonder if the Northstar engine was really good or bad.
Despite the use of the Northstar engine in various cars that did well on the market, General Motors stopped producing the Northstar engine in 2011. The last cars to ever house the engine was the Cadillac DTS, the Buick Lucerne, and the Cadillac STS, which came off the line for the last time in 2011.
If you are wondering if the Northstar engine is good or bad, this might be confusing, since the engine has been utilized in so many cars. The Cadillac DTS is a full-size luxury sedan that is produced by Cadillac and was the largest luxury car for the 2006 model year. The Buick Lucerne was a full-size car manufactured by GM from 2005-2011 and was one of the top-of-the-line sedan options from General Motors before it was replaced by the Buick LaCrosse. Finally, the last car to receive a Northstar engine was the Cadillac STS, a midsize luxury 4 door sedan that was manufactured from 2004-2011 and equipped with a six speed automatic transmission.
So, why did the production cease? Once the Cadillac STS had the last Northstar engine, it was replaced by the GM LS small-block OHV engine, used in newer Cadillac models and using a simpler, pushrod engine design that was considered to be more reliable and consistent. These V8 engines were the only engines used by Cadillac for almost the next decade, until the Blackwing V8 engine was produced in 2018.
With a long timeline of being used in Cadillac cars, you might be wondering if the Northstar engine is good or bad? We are going to give you some insight here.
Northstar Engine Development
GM began the process of designing the Northstar engine in the early 1980s when they anticipated the need for a dual overhead cam in the V8 engine which was a piston engine in which the camshaft is located in the cylinder head above the combustion chamber. With the feeling of direct competition about to happen from overseas in Europe and Japan, GM needed to stay up to date with the times.
Before the Northstar engine was produced, Cadillac was using the HT Overhead Valve V8, which is a piston engine that uses valves located in the cylinder head above the combustion chamber. Cadillac began producing new models to use the Northstar engine that he hoped would be direct competition against the luxury cars from BMW, Mercedes, and Lexus.
With the production of the Northstar engine, with the consumers wondering if the Northstar engine was good or bad, the numbers did the talking. The engine was capable of putting 300 horsepower out of its 4.6-liter engine, complete with a 90 degree V8 block with 4 bore spacing split into upper and lower halves.
The cylinder liners and the aluminum piston included valve clearance, with the valves striking the pistons if they lose timing. However, the Northstar engine used 4 valves per cylinder and maintenance free cam-drive chain use to prevent any repairs or replacements necessary within the mechanism.
One notable feature of the Northstar engine includes the limp mode, which allows the engine to keep running for a short amount of time without any coolant running through the system in case of an emergency. With the car supplying fuel to only one cylinder bank, the engine would cool the inactive bank in order to allow the engine to maintain safe temperatures and being able to drive for 100 miles without any further damage, showing how the Northstar engine can be considered good and productive
Northstar Engine Series
The engine was first introduced back in the early 1990s with the Cadillac Allante, a two-door, two-seater luxury car produced by Cadillac from 1987 until 1993. The Northstar Engine became the standard choice for Cadillacs, giving ammo to the “pro” side in the Northstar engine good vs. bad debate.
The 275 horsepower Northstar engine was used on all Cadillacs, while the Deville Concours and the Sevilles were fitted with the higher horsepower 300 hp version. The original Allante also featured the subsequent Northstar engine system, which contained traction control, adaptive suspension, and anti lock brakes, a mechanism that is an anti-skid braking system to prevent wheels from locking up while driving on slippery surfaces.
The Northstar engine was also sold under that name by Cadillac for over a decade before being used in both the Pontiac Bonneville and the Buick Lucerne in 2004 and 2006. However, the 4.0-liter Northstar engine was used in the Oldsmobile Aurora and the Oldsmobile Intrigue, showing how the Northstar engine “good” debate was in full swing, since the Northstar was being used in other companies besides just Cadillac cars.
L37 Northstar Engine
The L37 Northstar was the original Northstar engine, producing ample responsiveness and power, which shows the consumers and the companies how the Norhtar engine can be quite good. The L37 code is used on high-output transverse Northstars, with a compression ratio of approximately 10:1. The original L37 features and performance produced 290 horsepower, with the engine topping out at around 300 horsepower. This shows that the Northstar engine produced some of the most powerful domestic front wheel cars on the market, and the Northstar engine and the performance are very good.
LD8 Northstar Engine
The LD8 engine is a transverse V8 for front-wheel drive cars that were first introduced in 1994 and designed to provide more torque than the L37. used on all torque-tuned Notaris, the compression ratio is 10:1 and is quieter than previous Northstar engines, due to a tuned intake system and better hydraulics.
Head Gasket Issues
One Of the most prevalent and common problems in the North star engines is the head gasket issues, which shows why one could argue the Northstar engine is bad in the Northstar engine good vs. bad debate. Many Northstar engines have reportedly experienced head gasket failure, which can be quite an important and expensive repair.
The problem occurred when the engine ran hot for too long of a time and the head bolts would pull out of the aluminum block, resulting in a leak of coolant and a loss of coolant moving into the combustion chamber. This is especially evident in Northstar cars that have heavy and billowing white smoke coming from the exhaust pipes of the vehicle.
The failures of the head gasket in the Northstar engines caused the engines to run very hot and overheat while driving, which in turn, made the problem worse and get worse faster than it normally would have. Repairs for this issue are especially expensive and at the high end of the price spectrum, since the engine will have to be removed from the chassis to do the repair, showing how Northstar engines can be a bad choice.
The most common years of the head gasket issues for the Northstar engines are 19097-1999, with the 2000 change of Cadillac lengthening the head bolts severely reducing the prevalence of the issue in Northstar engine cars. This decreased the chance of having the failure, but did not completely eliminate the issues, showing how the Northstar engine remained bad in the following years.
However, once 2040 and 2005 model years came around, the head bolts were replaced using the LS6 head bolts which were longer than the originals and had a coarser thread with a better girl, effectively altering the issue and making the 2005-2011 Northstar V8s no more prone to head gasket issues than other aluminum V8 engines.
The Northstar engines after the 2004 and 2005 model years are known for their long lifespan and reliability, and show how Northstar engines can be good vs. bad when compared to the earlier models.
How to spot a head gasket leak in a Cadillac Northstar Engine
Now that you know head gasket issues are a prevalent problem in some model years of the Cadillac cars, you should know how to spot a head gasket leak. Head gasket leaks can oftentimes be hard to identify and diagnose in a Northstar engine, showing how this engine choice could be bad when fixing your own vehicle.
The typical symptoms of head gasket failure include the radiator needing to be constantly stopped up with water after minimal use and plumes of smoke emitting from your exhaust pipe. However, with some Northstar engines, these signs are not always apparent and easy to spot. Instead, make sure you keep an eye on your dashboard’s coolant indicator light. If you see the level of this light dropping very quickly in a short amount of time, this can be a sign that the coolant is leaking in your vehicle.
Although the Northstar engines are famed for their “limp” mode to keep the car running safely and prevent any further damage, it is strongly recommended to stop driving as soon as you notice this is happening. This limp mode is used to keep the engine running even when the coolant tank is dry, but this can sometimes actually damage the engine further, showing the Northstar engine can be bad when the coolant is leaking.
Other issues with the Northstar engines that have gone bad are the oiling in the cars. General Motors fixed a lot of these problems after the 2000 model year, but earlier cars develop leaks around the seals and valve covers in the vehicle. The oil pressure can quickly plummet, especially on the early Northstar engines in the 1993 and 1994 models, as a result of the debris caught in the oil pressure relief valve.
This problem will require the owner to replace the seals and the gaskets, with the gaskets being a bit tricky and time-consuming to fix. The engines use external oil pumps mounted to the front of the engine block, so if you see the low oil pressure, you can easily remove the oil pump and clean out the debris.
For cars in the pre-2000 category, they tend to go through oil much quicker than newer and more modern vehicles. The oil is not leaking in these cars, but it is being burned off quicker in the combustion chamber. The problem relates to the piston rings, which can get stuck due to the carbon buildup in the rings. When the piston rings get stuck in the grooves, they can;t do their job of wiping the cylinder walls and cleaning the engine.
This can allow the engine blow-by to go directly into the crankcase and cause a huge decline in power and fuel economy, showing how the Northsatrr engines can be bad in the earlier models. GM installed a ring-cleaning procedure for these cars that involves filling the cylinders with solvent to clean the rings.
Carbon in the Cylinders
The presence of carbon in the rings were solved by the 2000 model year, but created a different carbon problem of engines in the 2000 and 2001 model years building up carbons in the cylinders. The carbon deposits cause the engine to knock and ping under hard acceleration, showing the Northstar engine performing badly in the 2000 and 20001 model years.
Avoiding Northstar Engine Problems
Now that you know the most common Northstar engine problems, you can decide for yourself if the Northstar engine is good or bad. This engine is a good example of an engine that was over-engineered and has become high maintenance and expensive to repair in the occasion of anything breaking. However, these problems that spring up in many Northstar engine models are easy to deal with. So you have to make the call – is the Northstar engine good or bad?