Repair Video

Watch a Northstar head gasket repaired.

Cadillac Northstar


CARS WITH THE NORTHSTAR ENGINE:  1993-20010 Cadillac ** 2008-2010 Buick Lucerne Super ** 2004-2005 Pontiac Bonneville GXP ** 2006-2007 Buick Lucerne CXS ** 1995-2003 Oldsmobile Aurora **1999-2005 Shelby Series 1 ** 1999-2002 Oldsmobile Intrigue

A Northstar Air Bleeder Kit is included in all repairs.

The Cadillac Northstar rarely exhibits typical blown head gasket symptoms The most common symptoms for a Northstar, are unexplained coolant loss & overheating. Often there is no white smoke from the exhaust, no water in the oil.The more extreme cases show white smoke – which can still be repaired.


The Northstar engine features a die-cast aluminum block and aluminum heads. The Northstar was designed to produce more power to compete with BMW, MBZ, and new luxury cars like Lexus & Acura. Installed in Cadillac's and other models from 1993 to 2010. 


Coolant system problems have plagued the Northstar engine because of some design flaws that have never been corrected.  

  • Over time the steel head bolts and the threads in the aluminum block will begin to “stretch” and the head will seperate from the block, usually around 100,000 miles.
  • The design of the thermostat housing also contributes to the overheating problems.





 Often when a Northstar overheats, a mechanic checks the cooling system and finds nothing wrong. With no clear indication as to what’s causing the overheating problem, a mechanic may suggest replacing various cooling system components, like a radiator, water pump or thermostat. Eventually, the coolant starts disappearing again and the overheating returns. If this sounds familiar, it is time to get a proper diagnosis. An experienced Thermalweld technician can provide the fastest and most cost-effective solution to your problem. 





 Let us help you properly diagnose your Cadillac’s overheating problem and ultimately determine if you have a head gasket problem. To repair the head bolt problem requires a complete teardown, rethreading the holes & replacing the head bolts. Some repair shops refuse to replace a Northstar head gasket, the ones that will, the starting price is $2,400 up to $4,500. Many suggest “just replace the engine”. Replacing the engine is in the $6,000 to $7,000 range. 


Sign up to hear from us about specials, sales, and events.

Get in touch