Coolant leaking? Could be your coolant expansion tank...
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A customer called a few days ago saying his 996 Carrera had a coolant leak, asking if we could fix it. We focus on performance upgrades here, but he was hesitant to drive the distance to his dealer and since we are the closest shop, we decided to make an exception.
Coolant is a pretty nasty substance and this is a particularly messy job.![order](https://rennlist.com/forums/graemlins/order.gif)
The car was a stock '01 Carrera with about 66,000 miles on the odometer. The car was not overheating or throwing lights, but would leave a small puddle of "something" after a long drive.
![](http://videos.g33kd.net/996_coolant_expansion_tank/P1090098.JPG)
Once on the lift, it was clear there was something leaking right above the driver's side exhaust.
![](http://videos.g33kd.net/996_coolant_expansion_tank/P1090099.JPG)
![](http://videos.g33kd.net/996_coolant_expansion_tank/P1090100.JPG)
Looking inside the engine compartment, coolant appeared to be leaking from the lower half of the expansion tank. I removed the cap up top, and drained the coolant (using 5mm hex to remove the drain plug).
![](http://videos.g33kd.net/996_coolant_expansion_tank/P1090101.JPG)
![](http://videos.g33kd.net/996_coolant_expansion_tank/P1090103.JPG)
And while here, it's a good idea to change the thermostat, so I removed the four bolts holding the thermostat housing. To make these more accessible, it's necessary to remove the 3x10mm bolts holding the smaller hard line in place.
![](http://videos.g33kd.net/996_coolant_expansion_tank/P1090105.JPG)
![](http://videos.g33kd.net/996_coolant_expansion_tank/P1090106.JPG)
Here's the housing, removed from the car:
![](http://videos.g33kd.net/996_coolant_expansion_tank/P1090112.JPG)
The thermostat's a bit tricky to remove from the housing without the proper tools, so I had James work his magic to remove it.
I cleaned the surfaces of both sides, and replaced the gasket to reinstall in the housing and plug.
![](http://videos.g33kd.net/996_coolant_expansion_tank/P1090124.JPG)
The culprit, seen from above, requires removal of the intake and air pump.
![](http://videos.g33kd.net/996_coolant_expansion_tank/P1090125.JPG)
The tank attaches to a few hoses, the coolant level sensor, and a zip-tie. Once these are removed, it still has to slide out of its corner, which proved to be the most difficult part of the replacement.
I also had to disconnect two fuel lines, and lower the engine (
) a couple inches in order to remove the tank.
![](http://videos.g33kd.net/996_coolant_expansion_tank/P1090127.JPG)
The old tank, finally removed from the car:
![](http://videos.g33kd.net/996_coolant_expansion_tank/P1090130.JPG)
I also replaced the coolant level sensor, because it was brittle and worn.
Here's the picture that tells the whole story... the new tank versus the old tank:
![](http://videos.g33kd.net/996_coolant_expansion_tank/P1090129.JPG)
Just 8 years and ~60k miles ago, that yellow tank probably looked just the same! Next time you notice a small puddle behind a 996, 997, Boxster or Cayman, follow the leak up and you'll probably see something similar to this. But don't panic: it can be fixed.
Coolant is a pretty nasty substance and this is a particularly messy job.
![order](https://rennlist.com/forums/graemlins/order.gif)
The car was a stock '01 Carrera with about 66,000 miles on the odometer. The car was not overheating or throwing lights, but would leave a small puddle of "something" after a long drive.
Once on the lift, it was clear there was something leaking right above the driver's side exhaust.
Looking inside the engine compartment, coolant appeared to be leaking from the lower half of the expansion tank. I removed the cap up top, and drained the coolant (using 5mm hex to remove the drain plug).
And while here, it's a good idea to change the thermostat, so I removed the four bolts holding the thermostat housing. To make these more accessible, it's necessary to remove the 3x10mm bolts holding the smaller hard line in place.
Here's the housing, removed from the car:
The thermostat's a bit tricky to remove from the housing without the proper tools, so I had James work his magic to remove it.
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
The culprit, seen from above, requires removal of the intake and air pump.
The tank attaches to a few hoses, the coolant level sensor, and a zip-tie. Once these are removed, it still has to slide out of its corner, which proved to be the most difficult part of the replacement.
I also had to disconnect two fuel lines, and lower the engine (
![surrender](https://rennlist.com/forums/graemlins/surrender.gif)
The old tank, finally removed from the car:
I also replaced the coolant level sensor, because it was brittle and worn.
Here's the picture that tells the whole story... the new tank versus the old tank:
Just 8 years and ~60k miles ago, that yellow tank probably looked just the same! Next time you notice a small puddle behind a 996, 997, Boxster or Cayman, follow the leak up and you'll probably see something similar to this. But don't panic: it can be fixed.
![jumper](https://rennlist.com/forums/graemlins/jumper.gif)
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Dan,
Nice write up and even nicer that you guys helped out this guy, even though you don't normally do this type of maintenance work! Kudos to you and SharkWerks!
Nice write up and even nicer that you guys helped out this guy, even though you don't normally do this type of maintenance work! Kudos to you and SharkWerks!
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#6
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Danny Boy, I thought you were the "aircooled" guy. How did you get stuck with working on that?
Is James still punishing you for coming out and playing with us last Friday?
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#10
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Yep - I did this job on my old 2002 and it was ugly. Now I have a new 2002 I can't help but notice the tank is *very* yellow looking. Just a matter of time I suppose.
Nice work with the post. When I did mine a year.5 ago the search tool didn't bring much up. Take heed future people - a partial engine drop is part of this deal and the OP glossed over how tricky it is to work that tank out of it's hidy-hole even with the motor out of the way. Buy a dictionary of cuss words because by the time you're done you'll have used up all the ones you know already.
Nice work with the post. When I did mine a year.5 ago the search tool didn't bring much up. Take heed future people - a partial engine drop is part of this deal and the OP glossed over how tricky it is to work that tank out of it's hidy-hole even with the motor out of the way. Buy a dictionary of cuss words because by the time you're done you'll have used up all the ones you know already.