This article is one in a series that have been released in conjunction with Wayne's
101 Performance Projects for Your Porsche Boxster. The book
contains 312 pages of full color projects detailing everything
from performance mods to changing your brake pads. With more than 950+ full-color
glossy photos accompanying extensive step-by-step procedures, this book
is required reading in any Boxster owner's collection. The book is currently available and in stock now. See The Official Book Website
for more details.
Check out some other sample projects
from the book:
Proper maintenance of your coolant will go a long way towards extending the life of your radiator. The cooling systems on most cars are often very neglected, as most owners don't know much about them (see Project 29 for more information). The most vulnerable components in the entire system are the radiator and the heater core, as they tend to be damaged by corrosion and electrolysis. Poor maintenance of the system can result in the build-up of corrosion elements in both the radiator and heater core, creating clogs and leaks that decrease cooling performance. If the engine overheats, the additional heat from the coolant can also damage sensitive plastic attachments and components.
When replacing your radiator, you want to make sure that you replace it with one that meets or exceeds the OEM cooling standards. Although Porsche cooling systems don't typically fail very often, age and neglect may lead to overheating problems. Therefore, it may be a wise idea to install a center-mounted radiator that performs a better job of cooling than the standard pair (see Pelican Technical Article: Center Radiator Installation). I also recommend replacing your water pump, radiator hoses, thermostat, and any hose clamps too (PelicanParts.com sells complete kits for this replacement). All of these components can be damaged by a cooling system that has overheated. It's also a good time to swap out your old belt.
The first step in replacing your radiator is to remove all of the coolant from the system (see Pelican Technical Article: Coolant Replacement / Coolant Flush). Now, you need to gain access to the radiator. Remove the front bumper cover and pull back the front part of the inner wheel well liners (see Pelican Technical Article: Front Bumper Removal). It is possible to remove the radiators without removing the front bumper cover, but it takes only a few minutes to remove it and it makes the job a whole lot easier in my opinion. Follow the removal procedure detailed in the Photos to remove the radiator / fan assembly. Shown here are photos from the 1997-04 Boxster, but the 2005-08 models are very similar in nature.
The installation is basically the reverse of removal. Use new clamps on your new radiator hoses. Top off and bleed your coolant system as detailed in Pelican Technical Article: Coolant Replacement / Coolant Flush. Keep an eye on the front of your car for coolant leaks for about a week after the installation and tighten up any hoses that show any signs of leakage or weeping.
It's a good idea to use these instructions to clean out the radiators every spring, as they tend to collect a lot of debris which decreases their cooling efficiency over time. This can also lead to moisture collection and premature corrosion of the radiator.
It's also a good idea to check the proper operation of the radiator fans while you have access to them, as the resistor packs that help to power them tend to fail. You can turn on and test the fan speeds using the Porsche PST-2 tool, or you can simply turn on the air conditioning system, and that should trigger the
low-speed level of the fans. If you start the car and let it warm up, it should start the fans in low speed mode before graduating to the higher speed mode.
With the front bumper removed (Pelican Technical Article: Front Bumper Removal), you should have easy access to both the right and left radiators. Begin by removing the large rubber air funnel that is located in front of each radiator: it is held on with five screws (lower left). Then, cut a slit in the lower radiator hose and allow the coolant to empty out of the radiator and hoses (yellow arrow, upper right).
Detach the air conditioning condenser from the front by removing the two bolts (green arrows) and sliding it out of its mounting tab (red arrow). Using a zip-tie, secure the air conditioning condenser to the chassis. This is to assure that the condenser pipes do not become damaged while you're working on the radiator (upper left inset). The lower left inset photo shows the rubber air funnel for the right side of the car: the temperature sensor boot must be carefully threaded out of this boot upon removal.
This photo shows the backside of the radiator and fan assembly with the inner fender liners removed (see Pelican Technical Article: Front Bumper Removal). In order to remove the radiator and fan assembly, you need to disconnect the small radiator vent hose (red arrow). I recommend replacing this hose during this procedure, so you might save some time and effort by just clipping it off. Unclip the vent hose from the radiator bracket (blue arrows). The green arrow shows the upper radiator hose. In a similar manner, I also recommend just cutting it, since you will be replacing it anyways. Sometimes it can be nearly impossible to remove the hose from the radiator, and you will need to cut it off to remove it (inset photo). If you decide not to remove the front bumper cover, then you will need to remove the fender brace (white arrow), and detach the headlamp vent hose as well.
The yellow arrow shows the electrical connection to the fan that must be disconnected. Pull out the resistor pack from its bracket and loosen the wire harness (green arrow). Disconnect the rear radiator air guide from the metal radiator bracket (red arrow). Finally, disconnect the bracket from the chassis by removing the nuts that hold it in place (blue arrow).
On the left is shown a brand new OEM replacement radiator. If you are merely replacing the radiator fan and are reinstalling the old radiator, be sure to blow out the dirt and debris with some compressed air (right).
The radiator fan assembly is clipped to the rear of the radiator using metal snap clips (inset photo). Remove these snaps, and the fan assembly should lift right off. The fan is attached to the fan housing via three mounting screws located on the backside. A new fan is shown in the lower right.
Comments: I replaced both my fans without draining coolant.
October 24, 2013
Followup from the Pelican Staff: Thanks for the additional Info. We appreciate it. - Nick at Pelican Parts
Comments: Do having grill guards installed help keep radiators from getting dirty and at a lower temp.
September 13, 2011
Followup from the Pelican Staff: I'm not specifically sure which product you're referring to, but yes, putting some type of guard in front of the radiators can't hurt unless the guards themselves get clogged and block airflow to the radiator. They will also probably increase the resistance of airflow to the radiators, but that shouldn't make a noticeable difference in my opinion. - Wayne at Pelican Parts
Comments: Hi Wayne,
I just need to replace the fan.
Do I need to remove the radiator or can I just remove the fan directly just removing the inner fender liners?
August 6, 2011
Followup from the Pelican Staff: Good question, I honestly don't remember though. I know that you can get to the fans by removing the front bumper, I'm just not 100% sure that all of the brackets and plugs that attach to the fan can be accessed without taking off the wheel well liner. I think you can do it, but I'm not 100% sure. For this article, I took off the wheel well liner. I'll copy this topic to the forums, and perhaps someone there can refresh my memory. - Wayne at Pelican Parts
Comments: To just replace the radiator fan do you have to drain the coolant and remove the radiator, or can you leave the radiator hoses connected and just remove the fender brace, the rad support frame and then the fan housing?
May 10, 2011
Followup from the Pelican Staff: I believe that it's possible to remove the fans from the radiators without actually disconnecting the radiator hoses. However, I have never done it in this order, so I will copy this question to the forums so that someone there can confirm? - Wayne at Pelican Parts
Comments: Error in the article:
" It's also a good idea to check the proper operation of the radiator fans while you have access to them, as the resistor packs that help to power them tend to fail. You can turn on and test the fan speeds using the Porsche PST-2 tool, or you can simply turn on the air conditioning system, and that should trigger the high-speed level of the fans."
Turning on the A/C will trigger the LOW-speed level of the fans. Only engine coolant temperature of 90 degrees centigrade or higher correct me if that number is off, it's off the top of my head trigger the high-speed level. Porsche recomends running the engine at 2500 rpm to achieve this temperature quickly.
October 26, 2010
Followup from the Pelican Staff: Good catch. Thanks for the feedback. - Nick at Pelican Parts
Comments: sorry to appear to be unknowing .. cause I am .. if I follow your direction then the switch in the race car will control the on / off of high speed fan ??? regardless of what the car thinks.. lastly I thought the relay was open and closed due to other inputs from the car... just to clarify I want to be able to turn the fans on high or off manually by the switch,.. thanks again
August 16, 2010
Followup from the Pelican Staff: No worries. Yes, you are correct, the DME (main computer) will send a 12V signal to the relay to turn the fans on or off according to when it needs extra cooling (like when the A/C is turned on, or the car gets hot). What you need to do is figure out which pin is +12V and which pin is ground when the fans are turned on (this information wasn't immediately obvious from the electrical diagrams when I looked them up earlier). Then what you do is supply +12V and a ground to the relay terminals to turn the fan on. It won't matter what signals the DME will be giving to the relay, as you supplying voltage to the relay will "override" the DME and keep the fan on all the time that your switch is on. This method will not disable the DME either, so if your car decides it needs the fans on, they will still turn on, even if your switch is off. - Wayne at Pelican Parts
Comments: good advice.. as you can see don't know too much about this
August 16, 2010
Followup from the Pelican Staff: Thanks for the feedback - Nick at Pelican Parts
Comments: Thanks Wayne that's close to what I decided to do late last night.. but what I thought was to take the hot wire and snip it at the fan by pass the relays altogether and go straight to the fuses by way of the switch
August 16, 2010
Followup from the Pelican Staff: That won't work long term - your switch will fail and/or possibly overheat. You need the relay in there. The whole purpose of the relays is to handle the higher current from the fans. - Wayne at Pelican Parts
Comments: I want to operate the radiator cooling fans with a switch in my Spec Boxster. What do I have to disconnect and connect. thanks
August 14, 2010
Followup from the Pelican Staff: Well, the fans are driven by relays, so I would locate the position of the relays (they should be 21 and 22 under the dash for the high speed relays - see page 97-11 of the Bentley manual. ), and then power +12V to energize the relays across pins 85/86. One of those pins will be grounded and one will have 12V when the fan is running. Just take a 12V source, wire it into your switch, and then send it to the terminal of that relay that has 12V when the fan is running, and you should be good to go. Pretty easy... - Wayne at Pelican Parts
Check out some other sample projects
from the book: