CADILLAC / HYBRID

A Typical Sequence of Events in Cadillac Northstar Models

  • 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, 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 head gasket repair solution to your problem.
  • To mechanically repair the head bolt problem requires a complete teardown, drilling out the head bolt threads, installing new sleeves & replacing the head bolts.
  • Some repair shops refuse to replace a Northstar head gasket.
  • For 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 $5,000 to $7,000 range.
Cadillac Northstar Models
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Easy Repair Instructions

Step #1

Install Thermalweld’s Cooling System Modification Kit It takes about 15 minutes to install this device in the upper radiator hose. Once installed, it prevents thermostat malfunction and ensures proper coolant flow by minimizing air pocket formation. Follow the easy coolant system flushing instructions.

Step #2

Thermalweld Treatment

Shift into 3rd gear, drive 60 mph for 5 miles.

CUSTOM HYBRID FORMULA

The Hybrid head gasket repair solution comes with the same warranty as all Thermalweld products. The Prius is a well-known hybrid vehicle, it’s engine’s head gasket can be quite challenging to repair. The best head gasket sealer for hybrids is Thermalweld. Thermalweld has developed a head gasket repair solution for all hybrid engines. The solution has a thinner viscosity for hybrids. Unlike all of the other Thermalweld products, the hybrid solution can be mixed with antifreeze (flushing with water is preferred). It is always best to start with a clean coolant system. A blown head gasket in a Gen. 3 Prius usually is not the result of an overheating problem. The problem comes from what is known as “liner thermal expansion” in layman’s terms the engine is turning on and off multiple times during use. Every time it reaches operating temperature the block and head expand from the heat. Eventually the head gasket gives way due to the multiple thermal cycles.  Symptoms of a blown head gasket in a Prius 2ZR engine (Gen.3 2010 to 2015): Morning engine shakes that eventually clear up after driving a little. Loss of power. Loss of coolant. Check engine light - Code P0301 (misfire) Other causes of the morning shakes could be fouled spark plugs, dirty injectors, or a carbon clogged EGR valve, BUT if there is coolant loss, it is a blown head gasket. Continued driving a Prius or any other hybrid with a blown head gasket could cause a hydro locked engine, resulting in a bent piston rod. See the images (below) showing a bent rod, and a rod breaking through the side of the 2ZR engine block.

Bent Piston Rod
Hole in Block
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