Dock

Then you're reading things into my posts.

Essexmetal

WPOZZZ, The biggest cost for the cooling tube repair is the engine removal. I do a lot of these repairs and not all of the tubes show signs that the adhesive was going to fail. The only way you know if the tube was going to stay stuck is when you are taking it apart to clean it up for weld. Bit late to leave it alone at that point. It is all about risk mitigation. Most times at least one of the tubes show signs that they were starting to loose connection. Put a water pump in there while you are at it.

These tubes are just as likely to pop in a traffic jam on a hot day as they are to let go on a track. The difference is on the track you are at higher velocities and whether the coolant gets on your tires or the guy behind you doesn't matter, neither will have a positive result.

Since my experience is first hand and not computer keyboard based, I can support the others here when they say that this is not an issue exclusively caused by tracking your car. It is a design fault. One that can rest on the shoulders of the adhesive supplier. I guarantee that the adhesive and the assembly went through a life cycle test. There is no doubt that the test criteria was signed of by Porsche's release engineer and that the supplier's engineer had a sign off in there too. The one thing a life cycle test can not replicate exactly is real time. True time is something that has an effect on chemicals that can not always be replicated in a lab. This is one of those instances.

Forums being what they are, it is always entertaining to see the banter of opinions but I have to say that after a while I would hope that reality sinks in when the majority of respondents all say the same thing. Doc, give it up. You are wrong, tracking a car is not the trigger for the failure mode of these parts. The moment you have a set in front of you on a welding table feel free to contradict me. Until then forum derived subjectivity does not offset hardware derived reality.
Rick
Novi, MI

drh

Essexmetal, thank you for the reality check.

drh

Like I said, benefit of the doubt. Seems others feel the same way about the tone of your typed words. That is all there is since no one here is a mind reader.

Dock

And that's the problem with posting on forums...people jumping to incorrect conclusions. People never seem to attempt to seek clarification before labeling someone.

WPOZZZ

Rick, thanks for the advice. I probably put 2k on the car in a year and don't drive it very hard. My mechanic has the waterpump already and is waiting for the oil tank to show up. Then he will pull the motor and replace those parts. I spoke to him about the coolant lines while he's in there and just have to follow up with him on it. He has a good welder next door to his shop so I'm not too worried about that.

Dock

Based on some failures? Using that criteria, every part is a design flaw.

So all of those respondents have had a set in front if them on a welding table??

I wonder why the NHTSA didn't just take the opinions of those people and render an immediate judgement against Porsche??

cdk4219

For a racing association to condemn these cars directly due to the fittings failing not to mention the feedback from members with personal experience, it's enough for most. You should ldrive your car knowing that these fittings will stay in their original glued in place for the time you own your vehicle. Keep in mind it only takes one fitting to pop out and the game is over.

They are a very poor design, and will fail more frequently due to the age and heat cycle of the vehicle. Not all eight of them will fail on one car at once at any time ever, but I would speculate that there are many cars that have the same fitting fail from tension pulling he fitting out of it's glued resting place.

This is not a thread to scare people, just one simply stating the facts. These facts state that the adhesive sealer that porsche uses in the manufacturing of these parts is not up to the task of holding these parts together, and they are failing. This elementary design flaw should not happen PERIOD. There are many other ways to make a transition from an aluminum casting to change to a barbed fitting, and glueing without interference fit with this adhesive has proven not to be a good one.

Engineering change can be good, as there are many good things that can come from it. Some simple engineered parts are great for the fact that they are simple and work just great for longer than the life of the machine. This for one is not ground breaking engineering, as I see it it adds more complexity while decreasing performance.

Essexmetal

WPOZZZ, welding is best but I will never discount pinning them if you don't want to remove the water manifolds. The only issue is any swarf that gets inside from the drilling. Just noting that, weld solves all. I am sure your guys guy can handle it. Welding the 16ga. tube to the casting is not that tough but can keep you honest. I have had to fix a job where the welder just did not take the time to clean out all traces of adhesive. When that cooked and degassed it screwed the weld. The other thing that makes for a better weld is to grind the "elephant hide" off. Another word for the ask cast surface. Grinding that back to a smooth and surface where ever the weld bead will wick out assures a real smooth transition to the casting.
Rick

jumper5836

I have a modified 2001 996tt that got a ton of track days and it has never blown a fitting. Guess they used better glue in 2001. I am not planning on welding or pinning I run Royal Purple Ice and water. Protects and lubricates the cooling system while the water provides better cooling then coolant.

Essexmetal

CKD4219 makes some good points, especially the first one. I have worked in the auto industry for 30 years and the one thing that is very apparent, is that car companies are in the business of making money, not making cars. Initial cost and engineered cost reduction is king. That said I don't think the gluing of the tubes was intentionally chosen as the cheap way. I would bet that the adhesive supplier is world class, Henkel or Lord, someone like that. As noted earlier these don't fail instantly and I know they cleared dyno and life cycle tests. If it was an adhesive that was spec'd to cost then they could easily upgrade the adhesive while using the same tube design as a running improvement. Never kept accurate track but I am around 7 models years of the coolant manifolds. That is enough of a time span to certainly bring it to the attention of Porsche.

These manifolds are low production volumes. Only on the GT2, GT3 & turbo have them and they are very complicated casting to get coolant distributed all around that air cooled case. The complicated shapes would make some ends hard to turn a nipple onto the casting so I can see why they go to the tubes, cost yes but function also. If you think of the other cooling connections on the motor with Orings and rubber hoses one could assume an all metal connection with a proven adhesive is a no brainer. Its the age degradation thing that could not be predicated.

I don't think this is any worse than Porsches other failed components over the 911 history, well except for the fact that this failure can cause more than just damage to your wallet. It is capable of injuring someone. 911 history of failure.... chain tensioners, head studs, valve guides, etc. and the mother of all IMS bearings. When it comes to the numbers there are a lot less coolant manifolds out there than any of the other failing components. But again it is a safety issue so one is too many.

After 19 pages of this post I still find it easier to fix Porsches miscues verses trying to understand what point Doc is trying to make? Doc please give us the Cliff Notes version, what point are you trying to make?

Dock

Have you read all my posts in this thread?

John McM

Not on my 2001TT. I blew a coolant fitting on the track.

cdk4219

03 x50 83,000 miles shouldn't happen at 10 million miles IMO bad, very poor engineering choice of non pressed fitting, and subpar adhesive. I would expect this from a Chinese auto manufacturer.

cdk4219

Is this fitting by any chance the one that feeds the heater core?