rodsdream

Hi all, my 2009 997.2 S 54K miles which, I bought this last January has a very small leak. On the drivers side at the bottom of the engine is what I believe is the thermostat housing. Atached to that aluminium housing is a hard black pipe which is held to the housing by 3 E10 screws.

Before I bought the vehicle I documented in a previous thread that for several weeks the Volkswagen dealer that was selling the vehicle advised I could not test drive the vehicle as it had a minor coolant leak. Then I was told a few weeks later I could but only a drive around their parking lot. All along they stated the part in question was on back order. Eventually the part came in but it was the wrong part. They then advised the car was fixed without any parts.

A PPI was done by an Indy Porsche shop. No issue was found with coolant leaks. Becoming familar with the vehicle I eventually observed the small spring above the plastic coolant reservoir which was vertical but thought nothing of it. After reading more about the car I realized the spring should be horizontal and that the spring was used to bleed the system. Placing the spring horizontal has now caused the black plastic housing to weep coolant as the system is now pressurized. Further inspection revealed that the bottom of the plastic housing was 3/16" away from the aluminium housing while the rest of it was flush. Looseing all 3 E10 screws and getting the pipe seated / retorqued to 13NM has not helped. The leak continues needless to say yet another unscrupulous dealer.

Can anyone advise on repair procedure, in my search I found Porsche part # 9A1 106 338 00 which is a flange which presses down on the black pipe when used. Help All ......

galaxie5004

Hello.
My 2009 C2S had exactly the same issue. A small weep from this union of black plastic to aluminium thermostat housing. The flange part you describe is as we say in UK a ‘bodge’ - and honestly a poor solution to a very poor piece of design by Porsche. However, mine has stopped leaking so I guess it works in some cases. Problem is actually fitting it; coolant need to be drained down and the flanges on both sides cleaned and dried thoughly. A new gasket needs fitting and this is tricky. We had two attempts at mine before a good seal was achieved.
I believe the 991 has a much modified thermostat & water pump design to get round this problem.
not sure if a retro fit of this modified part is possible for our 997.2? Anyway, best of luck with your leak. It’s certainly possible to fit the flange without total disassembly but fiddly.

rodsdream

Galaxie, thanks for your response. That was exactly what I was looking for. Can you tell me how much coolant came out after the 3 E10 screws were removed as I plan to remove them and just see how much drains. I did buy 1 gallon of zerex g40 concentrate. I also have to buy the flange. Secondly is the gasket an oring that fits in a groove or a flat gasket ?? Thanks Rod

rodsdream

I was able to find that hard plastic pipe which, should be part # OPB121076 ( 1445370) . One end of that pipe does not take a gasket or oring the other takes an oring. Can anyone confirm which end mates against the thermostat housing. Or am I looking at the wrong part number?? Thanks All

Floyd540

That is the correct part number. The long sweep end of the pipe (shown in your picture) uses an O ring that fits in a groove molded into the pipe. The other end which has a hard 90 degree turn has a smooth end on the flange. The pipe comes with the O ring. If you just need the O ring, the part number is OPD121437. It is not really an O ring but a molded rectangular shaped cross section. I think it is used in other places in the water system.

galaxie5004

Hello.
To be clear, I didn’t do the leak repair personally as I noticed the problem soon after buying my 997 so the dealer fixed it under warranty. They’d had some previous experience so knew of the flange bracket repair part but despite its fitting the union still leaked so I returned for further investigation. The gasket had not gone in correctly which was remedied and it’s been fine since. It’s very fiddly to fit and the mating surface needs to be totally clean and dry before sliding the gasket in between and aligning the plastic pipe. Then the flange clamp needs to be carefully fitted being careful to not over tighten it and evenly nip up the bolts. I asked if longer bolts were required but apparently the stock bolts are long enough to accommodate the flange clamp. I wasn’t billed for the work so not sure how much coolant is lost but I’d imagine it drops a load as the thermostat is very low in the system.
Hope you get it sorted.
Regards from London.

Floyd540

The "gasket" is like a rubber band ,rectangular in shape ,about 3 mm wide and 6 mm tall with 8 nibs on the inside and 4 nibs on the outside. Sliding it in between the separated pipe and flange mount would be tricky to get right. You would need room to see and to work or it could easily go wrong.

galaxie5004

Hi Floyd.
As I wrote earlier, I didn't fit the 'gasket' but it's certainly in there and no leaks so its doing its job!
I do recall seeing it in the workshop when they'd ordered the outer flange but for some reason only the gasket arrived from Porsche.

rodsdream

Thanks to all for the timely responses. I ordered the flange and the oring as I am not planning on changing the water pump as yet fingers crossed. I did change the belt in January and checked all, pulleys water pump etc. all were good. I do plan on putting the rear of the car on a ramp like someone else mentioned on this site. He did an excellent write up on his 2018 911 which had low mileage but, had the same issue. He was very detailed in his write up with excellent pictures. Apparently putting the tail up results in losing 8 litres in coolant only. I will report back once I get the job done myself as I do not trust the Volkswagen dealer that I bought the car from as mentioned to fix the problem. PS I hope the part # for the oring is OPB.... and not OPD as mentioned by someone. Rod

Floyd540

Correction- The gasket/rubber ring is OPB121437. The water tube- plastic water elbow is part OPB121076 which comes with one of the gaskets.

rodsdream

I received the flange and gasket which took 2 weeks thank you UPS. I tried to just install the flange by just removing the 3 E10 screws and then retorquing them to 13 NM. To anyone who has this leak and it works for you to stop that leak/ drip you will only lose about 1/2 cup of coolant ( with rear wheels on ramps nose down). After starting the car and running engine for 5 mins with system closed the drip was the same as before.
I removed the flange 3 E10 and all the other E10 on the thermostat housing WITH the exception of the 3 E10 holding the thermostat housing cover. I lost about 2 gallons of coolant at this time.

The silver pipe which, has an E10 screw holding it in place just below the engine carrier bracket was also removed. In addition the horizontal black pipe had another E 10 holding it in place near the header pipes that too was removed. So in total 7 E10 screws were removed. I did have to remove the airbox as well in order to get to the silver pipe mounting bracket.
I am stuck as I am unable to pull the silver pipe out of the thermostat housing nor the black pipe on the front side of the thermostat housing. I have tried PB blaster , Corrosiox X, tapping with a hammer , prying with a large screwdriver and eventually vice grips with tape and cardboard which still managed to put teeth mark's on that pipe. JB weld will now have to be used to fill in those teeth marks.

What am I missing ?? Did I leave something on ?? I layed under that car for several hrs unable to figure it out. I was tempted to use tweezers to pull the old gasket out and try to clean both mating surfaces of the plastic pipe and aluminium housing but, was afraid of this not working once buttoned up. When the thermostat housing is pulled away from the plastic black pipe there is about 1/4" of space. I know someone said, a mechanic was able to do so but. That was on a 991 which, is not the same when it comes to how the pipes are held in place away from the thermostat. HELP ANYONE.
Rod