Cayman 987 2007/2008 coolling system leak. Water coolant housing? Replace coolant hose supply?

During a track day yesteday my Cayman started to leak from the cooling system. A lot. I have located a leak but after reading through most of the diagrams at the net, I can not identify exactly my leaking part. I guess it's the Water Coolant Housing (please see attached pictures). Question: If my guess is correct, is it possible to just replace the right coolant hose supply to stop the leak until next service at Porsche Center this autum? My question is based on the picture of the broken pipe gasket. Anyone who can advise me how to solve this. It's wrong time of the year having her queued at Porsche Center..... Thanks in advance //Plaincollar

Have you tried seating that hose fitting? These fittings have an O-ring on the far end of them.. so it allows a bit of flexibility in the joint, but this one is clearly displaced. You might try reseating it with the engine stone cold, and pressure relieved on the cooling system (remove reservoir cap .. then reinstall so if it starts to leak it isn't being pushed out. Reinstalling the cap will keep the coolant from rushing out even if the joint gets displaced even more. The wire bale around the female fitting is supposed to lock into the metal fitting on the hose, preventing this from happening. My WAG is one side is snapped in, the other has been displaced somehow.

Good idea. As you say, it's the connection that is broken so why even replace the hose. For the moment she will never become stone cold. It's over 90°F and the leak is quite comprehensive . But of course, I'll remove the cap and keep her cold before I try to fix it. I'll be back with feedback! Thanks

The actual hoses seem to be made to last forever. German hoses are amazing that way.. what can fail is the O ring on the fitting (that is available as a part - somewhere - unlike BMW who only sells the O ring with a new hose..) and apparently in your case the retaining clip. You probably want to poke around the female part of the junction a bit and make certain the wire bale is OK and the plastic it sits in isn't damaged. It's entirely possible the issue was just poor assembly at some time.

Yes. I agree. But i seems like the fitting has hit something (despite it's hidden behind the underframe) . As a temporary solution, is there any material you can wrap around the fitting to complement the o'ring. Like waterprof flex tape, vulcanized rubber or something like that? Finaly use the original clamp or some performance hose clamp? I don't think it will be tight enough just putting the parts back at place?. This is what it looks like when loosen the fitting from the hose.

Just my opinion from experience but the best way to handle this is to make the repair correctly. Not only will tapes and other sealant ideas likely fail, they could make the actual repair more complex and you don't want that. I'd lube that O ring with a bit of Vaseline , rejoin the fitting correctly and go from there after you test the motor at temperature and that union.

I'd replace the O-ring. They aren't expensive. FCP has them (as does Porsche ). I carry a set of new O rings in 2 sizes in my trunk, just in case. Since I have them with me I'll never need them (Eilenberger's Law of Spares).. And silicone grease is really the hot setup for lubing O rings. It not only lubricates them it protects the rubber from oxidation. Vaseline is basically petroleum-jelly, and that may attack and soften some rubber compounds.

Well, now I tried to reset hose fitting and it worked fine.After applyed the wire bale I could notice a satisfactory "click" when snapping on place. So far so good. But after driving a couples of miles without any problem, I went upp the highway at +7000 rpm and the hose fitting came lose again. Regarding what everyone been saying in this fhread, I assume the reason for that was the lack of new O-ring which I not been able to buy yet. Or maybe the wire bale has become to loose. (Anyway, what I did was to apply a hose clamp to make sure the wire bale was tight enough while I'm waiting for correct spare parts). In one way the solution worked but unfortunatly not all the way. The question is; is it enough to get a new O-ring and wire bale or do I need to change the water coolant housing as well as the hose to make a proper job? Thanks in advance

As you say, the weak spot can be the coolant house holder for the wire bale spikes (see picture). I'm not sure it they are deep enough to keep the bale spikes in place, meaning a new house is needed, That's the reason why I mounted an ordinary hose clamp outside the bale.I'll order a new water coolant house and the hose. though it's hard to find one looking the same. But as someone mentioned, FCP should have one. By some reason I'm only able to see page 1 of 6 in cooling system.But that's a first world problem.

FYI, if you need to get your coolant filled and car on the road again, I used O-rings from the $9 Harbor Freight "397 pc Metric O-Ring Assortment". These are Nitrile Rubber and I re-assembled with the correct silicon grease 14k miles ago. I have been prepared to replace them with factory parts at the first sign of a leak but so far not a drop or haze of dried coolant. Cheers, Julian

Edited your image - there are two things I see when looking closely at this (in green boxes): 1. The chips out of the metal fitting on the hose - the chips on that lip. those were made by something hitting the fitting. Dunno what, but if it was enough to chip the metal ring it undoubtedly was enough to loosen the fitting. 2. The slot in the housing where the bail goes through to lock the hose in position. It looked chewed up. Again, that could be the result of the hose being forced out of the female fitting. You may want to replace the hose and the plastic housing.. (and bale obviously.)

I allso noticed the damage on the hose fitting. I restored it to achieve a correct fitting to the house. But as I mentioned earlier, I will replace the house and the hose with new parts. That include the o-ring and grease as well A new leak has occurred! This time from the water pump. I have to blame my self for not bleeding the cooling system appropriate which probably is the reason. Replacing the water pump. is it something you do by your selt and if so, do you have to remove the tront engine mount to lower the engine?😕

This is a new water pump? Or you're considering replacing it? If you're going to DIY - you NEED a vacuum fill system. Since you're in Sweden I can't look up a local source for one, here is one on Amazon: https://a.co/d/29osidx - Perhaps you can locally source this tool. I wouldn't think of trying to refill a boxster/cayman cooling system without this tool. The long runs of plumbing going to the radiators are very difficult to fill, as is the heater core. Lowering the front of the engine will do nothing good, it may cause other issues. You do NOT want to overheat these engines, and doing the fill by any other means adds to the possibility of doing that. And before doing this - consider if you have the skill set and tools needed to do this successfully. If there is any question about that - think about having a professional do the job. I know the next question will be what coolant to use - use G40 coolant - https://a.co/d/65sptY2 50/50 mix with distilled water.

You are so right in everything you say. Yes, I'm buying new parts for replacement.Thanks for link. I'm sure I can buy it localy. And I've learned may lesson. I will not drive an inch before refilled the coolant by the book. I do think I have the skills to DIM. ( Porsche will do it for $1 900 no parts included and I have to order a tow truck to get it there which I just did but to my own garage. Last year Porsche charged $6 000 for for flywheel etcetera. It's a fun car but the value of the car is what it is.Everybody at this forum know the annual cost for those cars. So I feel that this is something I have to do my self). Or upgrade to GTS 2016 .

My local shop did the coolant change without the vacuum system. It took him MANY hours to get it done (they didn't charge me for the extra time, but it was VERY annoying). He had to tip the car in various directions, fill, run, bleed, yada yada. It was VERY annoying. I fully support the direction to use the vacuum filling process. Hell, I'm thinking of using this on my hydronic heating system in the house, because the morons that built it didn't put bleed valves in the right (highest point) location. Then I can use it on the car if I ever need to again

I actually bought the vacuum lift system and gave it to my shop (he's an old friend, but cheap as snot..) I figured the amount I spent on the system would be way less than the hours of labor he'd charge to actually get the air out of the system, so it was a win-win. He's mentioned using it again since I gave to him. I think that's also how he got a power brake bleeding tank - another customer contribution. He might be clever, back when I did hourly programming work, I always went for the slowest computer I could find to do the work on... nothing like collecting $$$ waiting for a program to compile.. and no incentive to make that happen more quickly.

@deilenberger Agreed, I should have done that (but I didn't think about it myself before I dropped my car off). That said, since you have one... is there a way to separate the gold knob or maybe attach a threaded fitting to that end? In my plan to use such a device on the hydronic system, I'd have to adapt it to that somehow. Alternatively, I could just use a T-fitting and put together my own pieces for the hydronic... after all, it's a valve, T-fitting, a gauge, and then some tubing. Not too complicated... but having the rubber sleeves would be useful.

I never "had" one - I bought one at Harbor Freight (where the kindly register guy was very careful to tell me I had up to 90 days to return it for a full refund.. which is possibly the reason it no longer appears on the on-line catalog..) and immediately took it to my mechanic and gifted it to him. The HF one had several different-sized tapered rubber sleeves, the smallest sleeve attached to the fitting that connects to the coolant reservoir, and if you need a larger one, it simply slipped over the one fitted on the device. You could stack them up so get almost any size > 1" that you might need. The actual vacuum pump on the device is a venturi-type vacuum pump: A good illustration of how one works.. and also shows the need for a constant source of high-pressure air (a pancake air compressor can be used with one - at least I was told someone did - but ideally you want a large piston compressor providing the compressed air..) In the illustration above - the air is used to create a vacuum that pulls the air out of the cooling system (and partly collapses the hoses). There is then a valve that shuts off the vacuum pump and transfers the connection to the coolant reservoir to a hose that is kept submerged in your new coolant (I premixed mine in a 5-gallon pail, with 50% distilled water. Mine took about 4 gallons of 50/50 mix). The vacuum left in the cooling system creates suction that pulled the coolant up the hose and down into the system. Easy-peasy. It took 10 minutes. I then drove it home, and after letting it cool overnight I found I needed to add about 300-400cc of coolant to the reservoir. I haven't touched it since then (about 10,000 miles.) -------------------------------------------------------------------------------------- To answer your question - I think so. I seem to recall the fitting the rubber tapered ring was on (it would be the "vac" above, but after an additional 2-way valve) had flats on it so it could be unscrewed. I have no idea what the threads were on it, or how difficult it would be to actually remove it. FWIW - when I had a new heating system installed 35 years ago (jeeze time flys..) the plumber added a hose valve on each of the return circuits for the heating loops (4 of them), and to bleed the system you just connect a hose up to them (going somewhere to a drain) and open the hose valve and lift the bail on the fill-regulator so full pressure is available. The water flow through the loop is fast enough that any trapped air is flushed out. Works like a charm (had to get a circulator motor replaced last year..) EDIT: I looked again on HF's website, and indeed they still have the one I bought as an item for sale. Cooling System Test and Refill Kit You can see the different size sleeves used to get the correct size.

Actually, I bought the vacum fill system you recommened from Amazon but they never send it! The delivery date was stated to19 July so I'm a little bit after schedule. ( Amazon refund me all costs). Maybe this Maddox can be a better option due there's no need to reinvent the wheel twice. Thanks for the links.