MASERATI HEATER CORE 4200/GS
Prone to failure in these cars and cause costly damage is the heater core, also known as the heater matrix.
Let’s begin with what this is, and does. The heater core of any vehicle is designed to provide safe heat in the cabin of the vehicle. This is accomplished by taking what they call a heater core, or heat exchanger, enclosing it in a box with a blower fan on the other side of it. When the blower fan is then switched on, it blows ambient air through the heated fins of the core/exchanger, this in turns heats the air, which is then routed into the cabin of the vehicle. Here is the one in this type of Maserati:
Now the heat exchanger/core is a bunch of small tubes coiled together with cooling fins all over it. Those coils are filled with antifreeze from the cooling system of the vehicle. It is constantly pumped through the car even with the blower motor turned off. There isn’t a by-pass valve when the heat isn’t being used. So even in the dead of Summer with the A/C on, the coolant is constantly flowing through the heater core. This is also true when the car is sitting and cold, it’s dormant but stays in the heater core. There are many setups in how this is accomplished. As it relates to this article I will be dealing with this particular Maserati.
As time has progressed with vehicles, the older vehicles used to have all copper cores, with copper end caps. This type seems to be the least problematic because of the cost and workmanship to make them. The manufacturing process has changed significantly in order to save money. The one in the Maserati has an aluminum core with plastic like end caps, like the two side by side above. This is where the failure begins. The sealant between the plastic, and aluminum deteriorates over time. There’s no real way to prevent it, and it’s not limited by the miles of the car. I’ve seen older cars with really low miles have heater cores that failed. I also personally own a Gran Sport less than 30,000 miles with it leaking. Here is the HVAC box where a heater core from a Maserati was leaking:
So what gives? Why is this even a major concern? A bit of Coolant leaking, who cares right? Unfortunately, no, that’s not the case. See the HVAC box that holds this heater core is positioned right in the center behind the dash. Right underneath you have an Air Bag control module, and on the passenger floor board (U.S.), you have your fuse box. So when the heater core bleeds out around the failed sealant, it drips onto the Airbag module causing the light to come on in the dash or worse to fail. This isn’t always the case because it can also drip around it. Additionally, it can drip down into the fuse box on the floor. I have heard of one car fire from this issue. I also personally replaced all of the leather around the tunnel of the Spyder because of the heated coolant dripping down causing the glue to soften and let go.
So as you can tell this is a pretty serious issue not to address.
What can Maserati owners do that own a 2002-2007 Spyder, Coupe or GranSport where this issue WILL present itself? First off, there are a couple of options. There is a place that makes an all copper heater core out of California. So you could go this route. This route is going to cost about $600. Please remember this is on top of the 12-14 hours worth of labor you are going to pay in order to have it done.
Maserati also has the regular replacement. It’s a few hundred dollars from any Maserati parts distributor. Personally, my favorite is just use a heater core from a 98′ Saab 9000. I think the interchange years are 92′-98′. It will cost you all of about $30-40 shipped to your front door from eBay or the like. With the Saab core, it looks like it might have a better make up than what Maserati used. But if you use a regular core that’s in the car you are only looking at a 10-15 year shelf life.
For a temporary reprieve from this issue. Please see my post on heater core/heater hose re-route. Mind you this is only until you have the money to replace the core. It you want to have heat in the car, you will need to fix the core. This is more of a peace of mind fix until you feel your funds are in order to do such a replacement. Use the A/C system as a defroster when needed most new cars use this method automatically.
HOW TO SPOT A BAD/LEAKING HEATER CORE
One of the first indicators is the Coolant reservoir in your Maserati seems to progressively lose coolant, but there’s no indication of coolant on the ground. It’s easy to test. Fill it right to the Max line on the reservoir, then check it periodically.
Secondly, you will smell the sweet coolant smell in the cabin when operation the HVAC system. After using the defroster for a period of time, and sometimes after 5-10 mins of sitting with the car off you will see this on the windshield. This is a Gran Sport:
Basically, you’ll be able to wipe this off the windshield and see it’s not normal condensation. Once I begin to smell or even think I see the coolant drop in the reservoir I immediately re-route the hoses in the car like suggested above. I don’t wait for the leaking coolant to cause any damage. It’s just not worth it.