Boxster Coolant Leak
 

I recently purchased an '02 Boxster with about 97K on the clock. Overall, the car is in pretty good shape, but it does have a few issues that will need to be sorted out.

After leaving it parked overnight, I am finding a small puddle of coolant under the front left corner of the car. I did a quick look underneath and there is a definite wet spot on the plastic panel behind the bumper. Is this a common leak, and is there a common fix?

I have owned and worked on BMWs for the last 20 years and am all too familiar with their notoriously crappy cooling systems. But I am new to Porsches and will have to learn their quirks.

Doing some research seems to suggest that access to the radiators is gained by removing the front bumper. But before I do that, I just want to know if there is anything in particular I should be looking for. Are there known weak spots in the cooling system that I should know about?

Water pump is a likely culprit

Come again? How would a leaky water pump cause a leak at the front of the car? Wouldn't the leak be under the engine?

You can take off the wheel and fender liner and see most of the hoses to check for leaks, but if there is no obviuos hose leak you will probably have to take off the front bumper cover (fairly easy) to check the radiator for leaks. Its a good idea to take off the cover so you can clean all the crud out of the radiators, condensers.

Here are the instructions for removing the front bumper cover (by way of our Forum owner, Pelican Parts):

Pelican Technical Article: Boxster Front Bumper Removal - 986 / 987

Looks simple enough to investigate. Thanks for the tips!

With that kind of mileage I would really look at replacing the water pump and since you are in GA also put in the low temp thermostat. New pump from SunCoast is about $258 and the thermostat, get the $75 one, it's the same one that LN Engineering is selling for $177 from Pelican Parts. Coolant, you can use any longlife, just use distailled water when mixing.:cheers:

Can I use BMW coolant? I have lots and lots of that stuff.

Another question: Does the coolant have some kind of vent or overflow? The reason I ask is because I accidentally overfilled the tank in the trunk, but didn't spill anything on the ground. However, there is now a large puddle under the rear of the car. I have never seen one in that area until I overfilled the tank. So I'm hoping it's just because I put in too much coolant.

I have since sucked out the extra and have the level right at the "MAX" mark.

The pump is nowhere near the front, so that's another issue.

Check under the car at the front corner for minor scraps or other damage that may indicate that the car's nose dropped on a curb while being parked. I bought mine with such a problem. The upward impact cracks the plastic locating piece and radiator end at the left end (looking rearward at the front of the car) of the radiator. You likely will not be able to see the leak that I described with the bumper on. In the attached photo look carefully for a cross shape at the end of the locator. That's what I had that was leaking.

I'd be cautious about the BMW coolant as it may have something special formulated especially for BMW.

If you are ambitious and can lay it up a little longer, the pump change would be prudent while it's drained down.

As for filling it, do a little more research. While filling it, crawl under and burp all the big hoses to get some air out. I disconnected hoses at low points to drain it too....that worked well.
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Hey BimmersInGA, I too am a BMW guy in GA (Atlanta) who started tweaking a Boxster about a year ago.

They obviously have some of the same German thinking with plastic mechanical and pressure parts in the cooling system, etc. I always replaced my BMW plastic parts throughout the car at about 100K miles, and it sounds like that my be a good approach for you with your P-car also. I'm guessing the plastic water box on one of your coolers is cracked.

Everyone on these boards seems to think P-car coolant is some special fluid from Heaven, so you might want to get some. Personally, I would think the BMW coolant would be fine, but you never know, and it is not too an expensive insurance.

You will also find that many of the P-car purists think Mobil 0w30 is the only suitable oil for these cars. Personally I don't trust the stuff, and use Castrol TWS - same as in my M3.

You will find that all parts for these cars are very highly priced, even from the aftermarket.

It is sure to be an expensive journey, but there really is no substitute...

Good luck.

So I'm not the only masochist in Georgia who has both BMWs and a Porsche? :)

You are absolutely right about replacing BMW plastic cooling systems at 100K miles. I do the same thing. Learned that one the hard way!

I did some quick shopping and it looks like a new radiator is about $250. Ouch! But I knew going in that Porsche is proud of their parts. I'm going to pull the bumper off this weekend and see what's what. Until I get in there, I won't really know what I'm dealing with.

Bobiam: The plastic panel under that corner is damaged and there is a piece of it hanging down. So it's likely to have been introduced to a curb by the previous owner.

I pulled the radiator out yesterday and it has the exact same damage as Bobiam's. It's apparent that the previous owner introduced that corner of the car to a solid object. The fender liner is trashed and the bottom of the bumper is scraped up.

After getting a good look, it's pretty easy to see how the radiator can be damaged in that way. The mounting post where it's cracked is essentially directly mounted to the body. Any impact with a curb or road debris will put an enormous amount of stress on that plastic mounting post. A few good whacks and it will crack - or even break off.

Mine leaked, too. I replaced the cap.

Coolant leak
 

I have an '07 Boxster. Got a warning to check coolant level yesterday. Opened the cap to do as suggested and heard a hissing sound. Then I noticed coolant on the garage floor. Is this normal for it to leak because I opened the cap??? BTW... couldn't see coolant so way below Min level. There seems to be a lot of discussion on line as to what coolant to use to replace it. Any help would be gratefully appreciated.

Hissing at the coolant cap is normal as you are dealing with a pressurized system. Whether the car is cold, warm, or hot has everything to do with coolant coming out of the over flow. The overflow is located in the space provided for your oil fill cap and coolant fill cap. Between the two at the bottom you will notice a small hole. If the car lets out some coolant when you open the cap because its warm or hot, then it will flow out this tube and run onto the floor next to the right rear tire. As far as coolant, Porsche uses G12 coolant and or the "Pink Coolant" for the 9x7 cars and more often than not Zerex or "Green Coolant" is used for 9x6 cars. If its been flushed sometime in the past it may have had the G12 put in it. Little bit more evironmentally friendly.

-Ty

*Speed Yellow 986*

Yes the 986 expansion tank has a plastic plate that can be removed if you take off the Coolant cap and the Oil fill cap. It the plastic base that sits under the caps. That is where you coolant over flow will be at. If you take a small bottle of water and poor it around the coolant and oil fill cap you will notive it leaking on the floor at the right rear tire. Normal.

-Ty

*Speed Yellow 986*http://986forum.com/forums/uploads01...1349532474.jpg

Hi - I have the same issue with a leaking front radiator after running over a FOOTBALL on a dual carrage way at night. The car is loosing water when the system is HOT only, but around 2 pints every 30 minutes.

Ive phoned the garage today - do I need to order a new front radiator ? or is there another fix to this issue.

Thanks in advance to any help.

That's not much information. You didn't mention the bumper or other obvious damage. But your accident must have broke something, and if I had to guess I'd say that the radiator's locating pin on the side closest to the front has been cracked/sheared. I doubt that the jarring could pull a hose loose. There is no repairing that radiator if I am correct, and the air scoop may have been ruined as well. Once the bumper is removed it will be clearer.

Thank you for the quick reply.

I've taken a look under the car and there is no visible damage to or under the front bumper. Just lots of dripping coolant leaking out on and around the front plastic flap in front of the offside wheel under the bumper itself.

I'm going to order a new radiator today and have it delivered to the garage for fitting. unfortunately the cost will be about £200 for labour and £125 for the radiator - expensive for running over a football. I wish I had a garage or somewhere indoors to work on it myself.

With a little patience and a good flashlight you might be able to see the source of the leak from below without removing anything. Of course with such a low car, you would need to jack up the front end and use jackstands for safety. You may need other parts as I mentioned earlier.
Perhaps the garage should get it onto a lift, remove the bumper skin and get a good look at it before ordering parts. The car can be driven into a yard for storage for a few days without the skin.
There's good slide show instructions somewhere on this forum if you need them.

The radiator was out yesterday evening. No obvious cracks or damage to the exterior.

Just the bottom corner which was yellow from the coolant and appeared rotten. The metal honeycomb crumbled when touched in this area.

So remains a bit of a mystery..photo attached. New radiator now in place. Cost £125 OEM.

Attachment 16773

No mystery.....Your radiator was ready to start leaking and you footballed it over the edge. You never mentioned the yr of the car or the miles on it. Do you KNOW about the coolant that was in it? If some replacement coolant not designed for the car, it could lead to early rot. Also, organic debris stuck in the radiator could possibly rot it from the outside. I hope the mechanic checked that out on the opposite side while the bumper skin was off. You got away easy....could have been worse.
What kind of coolant was installed with the repair???????

Thanks for your comments

year 2003 - 93k miles.

There was plenty of damp rotting vegetation in the leaking radiator.

Mechanic charged 3 hours labour. He did clean out the other radiator while the front skin was off.

The coolant previously in the car was yellow.

The coolant now used is a Pink colour - apparently its the most expensive stuff.

Im looking to change the car but cant really decide what to go to. The Cayman is nice, but more costly for essentially the same car. A newer Boxster is kind of the same again, and an Aston Martin v8 Vantage is 30k! plus running the thing.

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I had a self imposed hole in my front radiator from drilling a hole to run a wire. I will explain how I fixed it.

Revove the front bumper. There is a good post on this forum about how to do it. There are then two hoses and 4 bolts to remove the front radiator.

Once removed, spray the area to be patched with brake cleaner. Picture Shown. The guy at the autostore said it romoves the oily residue from the coolant. Then mix the two part epoxy and push it into the radiator as shown.

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Leaking Radiator
 

I was able to see if the epoxy stopped the leak by plugging the inlets with wine corks and submerging it in my sing.

If the leak still exists, you may have to do the following.

Remove the end cap on the radiator by bending back the tabs holding the plastic end. The end cap will come off. You will need to idenify which port the hole is in. Lucky me it was right on the end of one of the ports. Otherwise I would have to plug multiple ones.
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Drain it, and spray the areas with brake cleaner. mix the epoxy and push the epoxy in the port of the one with the leak. Let it dry overnight.

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If your hole is in the middle of the port you will need to plug both ends.
Test it in the sink.
This is about a 2 hour job.