Remanufactured Cadillac Northstar Engines
Because You Deserve an Engine You Can Rely On
We take pride in fixing the flaws others overlook producing Northstar engines that's stronger, last longer, and keep your Cadillac driving the way it should.
We take pride in fixing the flaws others overlook producing Northstar engines that's stronger, last longer, and keep your Cadillac driving the way it should.
Promar Precision Engines, based in Paterson, New Jersey, has over 45 years of experience as engine rebuilders and is committed to the highest quality products and services offered in the industry.
Promar Precision Engines is a professional engine remanufacturing company serving customers worldwide with a complete line of rebuilt engines / remanufactured engines, cylinder heads, crankshafts, engine restoration services and engine components for Automobile & Light Truck, Classic Automobile, Diesel (Light Duty), High Performance and Marine (Boats)
Promar stands apart by offering unparalleled expertise in remanufacturing. Our team combines cutting edge technology with meticulous craftsmanship to ensure every engine meets or exceeds original performance standards. Whether you're restoring a classic car or need reliable marine engine repair, we're here to deliver results you can trust.
At Promar we take pride in serving a diverse range of clients, from enthusiasts preserving vintage vehicles to professionals seeking performance upgrades. Our attention to detail and commitment to excellence have earned us a loyal customer base across multiple industries.
GM released the 4.6 Cadillac Northstar Engine in the 1993 Cadillac Allante. Since then just about every Cadillac vehicle has had used them as their power plant. As of now the Northstar has been all but phased out except for the DTS. The Northstar engines since the beginning have had several inherent design flaws.
1. Main saddles get out of round over time and result in low oil pressure.
2. Cylinder head bolts pull out of block due to coolant deteriorating threads and heat.
3. Blown head gaskets.
4. Overheating.
5. Oil leaks.
Promar Precision Engines have been pioneers in remanufacturing the 4.6 DOHC 32 Valve Cadillac Northstar Engines. We were one of the first remanufactures in the country to offer remanufactured 4.6 Northstar engines to the public, even before oversize pistons were available. We have made multiple enhancements and longevity increasing upgrades to the original O.E. design. With impeccable machine work, and our proven high quality engines backed up by our trend setting 3 year unlimited mileage warranty, Promar once again has all of our competitors chasing after our success. We offer all makes, models, and years of the 4.6 Northstar engine.
Every high quality 4.6 Cadillac Northstar Engine that we build comes includes proper block strengthening techniques to ensure no more blown head gaskets (and without having to use the overpriced and unnecessary cylinder head studs) and line boring with custom main bearings to eliminate out of round main bearing bores and any low oil pressure problems. Each engine is tested 100% for oil leaks, oil pressure, compression, water leaks, and porosity before it leaves our facility.
Our remanufacturing process ensures that each component meets the highest standards. From thorough inspections and precision machining to rigorous testing, we restore engine blocks, cylinder heads, and crankshafts to like new condition for dependable performance
Our remanufacturing process for engine blocks includes detailed inspections, precision machining, and rigorous testing. Each block is restored to like-new condition, meeting or exceeding OEM standards for reliability.
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Our remanufacturing of cylinder heads includes comprehensive cleaning, crack detection, and machining. We install plugs, check spring pressure, and add seals, ensuring each head performs reliably and efficiently.
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Our crankshaft remanufacturing process includes detailed inspections, grinding, and polishing to restore the crankshafts to precise specifications. This ensures a smooth and efficient engine operation with maximum durability.
Learn MorePromar Engines is proud to be BBB Accredited with an A+ rating, reflecting our commitment to trust and integrity. We offer flexible payment options including PayPal, allowing you to buy now and pay later with confidence. Your satisfaction and convenience are our top priorities!
Shop securely with PayPal and enjoy safe, convenient transactions every time.
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We meet the highest standards for trust ensuring peace of mind for every customer.
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Enjoy flexible financing options with payment plans that will fit your budget.
Learn MoreDiscover the difference with Promar Engines. We take pride in delivering top notch services to our customers. Don't just take our word for it hear what they have to say about their experiences with us! Our commitment to quality and customer satisfaction speaks through their success stories.
We have been a supplier to Promar since 2009. They are a great business partner - clear orders, fast payment and quick to share important information that benefits both of us as well as all of our combined cust...
1 week ago
Needed an engine at the last minute and nobody had the 6.2. Emailed these guys and within a hour someone contacted me and pulled one of the shelf for me till payday. Got the engine really fast and was very sati...
3 weeks ago
These guys were such a breath of fresh, honest customer service, thank you gentlemen for your time and advice.
3 weeks ago
Just had a 7.3 IDI international long block completed with ARP head studs and main bolts. This truck runs amazing now. Great customer service and support.
1 month ago
2026 UPDATE: I have put 20,000 miles on my 2.3L Ford Engine since PROMAR rebuild. Want to share the longevity of this rebuild with zero issues nor codes. Key to follow all PROMAR instructions with no shortcuts ...
1 month ago
Top notch business and the prices are unbeatable!!!
1 month ago
Great job you met my expectations dod delete true v8 now
1 month ago
I am extremely impressed with how fast they had my motor shipped to me. I believe it took 6 days from the time I ordered it to the time it was in my shop. So far, I have almost 1,000 miles on the new motor with...
1 month ago
great motor pentastar v6 jeep wrangler
1 month ago
Put a Promar 4.6 liter 2 valve engine in my 2001 Mustang rebuild. Was able to customize with a ProComp cam & polished headed. Promar engine runs great and car has more horsepower that the old engine. Further...
3 months ago
From TNT AUTO CENTER Pompano Beach Florida Thank You For a great job rebuilding hour 1960 390 cadillac motor. Also for cleaning valve covers ,oil pan , intake, no extra charge. Thanks Tom
4 months ago
Great job!!! Kevin was very helpful form start to finish..
6 months ago
Excellent experience start to finish with Promar! Purchased a rare, very hard to find, rebuilt 3.7l Mercruiser motor which I received in within a week. Installed the motor and it is running like a brand new mot...
6 months ago
Great product. Received it quickly. Second engine that I have purchased from promar. Very pleased.
6 months ago
Shipped on time , great delivery, motor look good assembled, runs great !!! Well worth the price !!!
6 months ago
Excellent customer service. Super easy to order and work with. The engine I bought was delivered in a timely manner. I definitely recommend.
6 months ago
Great experience with promar engine's! Got the new engine from them quicker than expected and looked perfect. After installing I ran through break in period and took it to tuner to double check everything was s...
7 months ago
Purchased a Non-AFM 5.3 to replace a failed engine in my Silverado. Shipping was fast and affordable. The engine runs great. Have around 1000 miles on it after having it tuned by Michigan Motorsports and HP Tun...
7 months ago
Great service and great product. I got my Gen2 Coyote long block from them a couple months ago, took my time building and installing, and just got my first start on it last night!
8 months ago
This is my second engine from them customer service is outstanding truly ..You will not be disappointed..Went with a 426 stroker….. Let’s just say I got more than what I asked for love the team …But that ...
8 months ago
For your convenience, here's a quick reference to important customer service details. Learn more about our payment options, sales tax policies, business hours, and other essential information to help guide your experience with Promar Engines.
We accept Business Checks, Certified Bank Checks, Cash, Money Orders, Paypal, Zelle, Apple Pay, Google Pay, Venmo, Wire Transfers and All Major Credit Cards. All funds must be in United States currency (US Dollars).
Please use the form below to calculate shipping cost for your area.
Delivery of the engine by truck equipped with a lift gate is $75 each way and residential delivery is an additional $100 each way. Those services are free for New Jersey customers.
Additionally, if your delivery address is a farm it's considered a residential property and will require Residential Delivery.
Shipping options are also available for customers outside of the United States. Please email sales@promarengine.com for more details.
Select your destination to get shipping cost.
All orders shipped within New Jersey will have 6.625% New Jersey state sales tax added.
All orders shipped within New York, Pennsylvania, Florida, North Carolina, South Carolina, Michigan or Illinois will have your current county sales tax added. We do not we collect sales tax in the other states.
Our normal business hours are Monday-Friday 7am-4pm EST. We can be reached by phone @ 1-800-422-6022 or by email info@promarengine.com
All engines, cylinder heads, and crankshafts are sold on an exchange basis. While there is no core deposit required, all cores must be returned. By purchasing our product you agree to have the appropriate, rebuildable core ready for pickup or paid for in full within 30 days. After 30 days your warranty will be voided and you will be charged market value for your core. Please call for immediate pickup.
For more information please feel free to call toll free Monday-Friday 7am-4pm EST@ 1-800-422-6022 or email us info@promarengine.com
Yes. We can remanufacture your original engine back to factory specifications.
Yes. We provide machining services for engine blocks, cylinder heads, crankshafts and connecting rods.
Yes. All customers picking up at our New Jersey facility must pay New Jersey sales tax.
Sorry, we can't help with vehicle repairs we are not mechanics. You may want to contact a licensed auto repair shop for assistance.
No. We are strictly a machine shop that specializes in remanufacturing engines. We do not remove or install engines.
No. We do not offer or remanufacture engines for these brands.
We do not offer in-house financing. However, we accept PayPal, which provides options such as Buy Now, Pay Later.