Tag Archives: Heater Core

Maserati Heater Core/Heater Hose Re-Route

 

Here is a step by step process to give you breathing room on a costly repair that needs to be done on your vehicle. I first published this on Maseratilife.com to help all Maserati owners who were facing this problem. It’s a safe effective way to deal with any coolant loss inside the cabin of the Maserati through the heater core.

First you’ll need some supplies from your local auto parts store. It doesn’t matter which one.  Here’s what you’ll need.

  • 3′ section of 3/4″ heater hose.
  • (2) 3/4″ hose joiners or couplers
  • (4) hose clamps to fit 3/4″ hoses
  • Extended life coolant preferably a good brand compatiable to be mixed with other brands of coolant.

The entire process should take maybe an hour.  The first part of this process is to remove all of the trim pieces around the engine compartment just to give you room to work with. Usually in this process I replace all of the trim screws with stainless steel screws and matching washers. In my opinion it gives it all a better look when it’s put back together. Additionally, you can use a small flat blade screw driver underneath the hood strut clamps in order to pull it up enough to detach the ball and socket.

After removing the trim pieces, you will be looking directly back at the fire wall of the car. The heater lines come out of the firewall slightly off-center to the driver’s side of the car. In the UK that would be the passenger side.  You are looking for these:

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The first picture shows the line coming from the firewall with a hose clamp on it. This is the top line. The second line however, which is directly below it in the photo actually follows the back of the fire wall behind the intake manifold, and 90 degrees right underneath the coolant reservoir. That’s what I am showing in the second/third picture. It is also why you will need 3′ of coolant hose. Essentially what you will be doing is disconnecting both of those hose clamps, and running a line of hose with a joiner to connect all of the heater hose together. When you are finished the hardlines of the heater lines will be disconnected and left open. (You can use electrical tape and wrap around both openings or find some end caps as well. You’ll want to blow those lines out with compressed air before you do so.)

Before I forget make sure you have a catch pan underneath the car to catch the coolant that will be lost when you disconnect these heater hoses.

Here are some more photos:

This is the top heater line again coming out of the firewall, as you can see it’s almost directly behind the driver’s side Valve cover. It’s a hardline that leaves and immediately connects to a rubber heater hose:

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Here is the second line following the firewall down towards the passenger side before turning, and connecting to a rubber heater hose.

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So now, you’ll take the 3 foot length of hose and connect both joiners to it like this (they can be plastic or metal joiners it doesn’t matter):

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You will then loosen both hose clamps going to the car’s hard lines, and connect them to this hose and joiners you just made. If you need to loosen the rubber lines, as they do get stuck from the hot/cold cycles use a set of open pliers, and rotate the hose back and forth to loosen it’s grip. You can also attempt to stick a flat blade screw driver between the hardline and rubber line to pry it up. When you have the lines connected they will look like this:

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You will want to loop the hose on the driver’s side fire wall around so the heater hose isn’t crimped like the lines show in the first photo above. Next tuck the heater hose down like this so it’s out of the way:

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After this last step, you are finished and can re-assemble all of your trim pieces.

 

 

Maserati Heater Core

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:IMAG2063

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.

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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:

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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.

OPTIONS

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:

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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.