tbarcelo

So it looks like I have a failed passenger side radiator:

https://picasaweb.google.com/twbarch...eat=directlink

First three pics show what I saw on the top of the passenger's side radiator before pressurization. Fourth pic shows dripping coolant from top left side of passenger's rad after pressurizing to 12 - 14 psi.

Questions:

1. Should I replace both left and right (and center)??
2. Should I replace hoses / o-rings?
3. Should I use Porsche coolant (I think green stuff is in there now)?
4. I virtually have these things out - how tough is the bleeding process?
5. Best place to buy everything?

Thanks.

Macster

Generally don't fix what is not broken. If the other radiators and hoses do not show any signs of leakage or other problems, leave them alone. (I asked about replacing the coolant hoses in my 02 Boxster not too long ago when I had it in for a coolant tank R&R and the tech told me two things: 1) He has not found the radiator hoses to require replacement. They seem to hold up quite well; 2) The cost is rather expensive. Roughly IIRC the estimate was $1000. If you feel some hoses need to be replaced they all should be replaced because they are all are subject to the same degradation.)

My recommendation is to use Porsche coolant and mix it according to directions and this includes using distilled water.

The cooling system filling process is greatly helped by using a system that pulls a vacuum on the cooling system -- to the point the hoses collapse -- then shut off the vacuum line valve and open a valve to a tank of pre-mixed coolant that is vented to atmosphere.

The low pressure in the cooling system will allow atmospheric pressure to push that coolant out of the tank into the cooling system with no air pockets.

Frankly I hate that fill the cooling system, then run the engine until hot, race the engine until hot, add more coolant and repeat. Horrible technique.

For the radiator and anti-freeze and other hardware one of the online/phone Porsche parts supply houses could I certainly supply you with the parts. There is of course always your local Porsche dealer parts department.

You want to be sure you get a geninue factory radiator and not an aftermarket one because chances are the aftermarket one is of poorer quality. Well, at the Porsche factory radiator is a known quality and generally these radiators are not substandard while some aftermarket radiator can be an unknown quality.

After you get the system back together and filled pressure test it cold and then hot to ensure after the repairs the system is once again pressure tight (or tighter) that there is not another leak that was masked by the bigger leak.

I don't think you'll find one but double check.

Sincerely,

Macster.

Renn 951

Macster:

Not to hijack this thread or anything, but what are your thoughts on the reported issues with the failures of the extruded aluminum piping extensions from the cast aluminum coolant manifolds on the GT1 based engines? The Feb 2011 issue of Excellence had a big write-up in the Tech Forum section on this. There seem to be lots of confirming reports on the Rennlist GT3 Forum where guys have had these failures, but in talking recently to a well-known local Porsche racing shop, those guys say they've never seen any signs of this in all the hours they've put on their GT3 racing engines. In fact, Excellence even says they contacted several well know professional racing teams and almost all of them said they weren't aware of any problems. Yet Excellence recommends considering one of several "preventive" modifications, but the ones that are sure to prevent the failure are all very expensive, requiring removal of the engine to execute the fix.

So this kind of fits in with your comment about not fixing what isn't broken, yet the possible consequences of a major coolant dump while on the track or otherwise driving the car aggressively could be severe.

Any thoughts on this?

Land Jet

Here is a picture of the coolant manifolds off my car. I bought machined fittings{in the bag} from ebay but can only use 3, the curved pipes have to be re-used. My tech will be welding them in. Everything has to come off the top of the engine to get to these. We are putting in a new clutch and LWFW so the engine and transmission are out of the car.

Even though I am doing this preventative repair there is no guaranty that the guy in front of me will not drop his coolant.

tbarcelo

Thanks, Macster. Can the cooling system vacuum process be done with something like so Motive bleeder or do you need a cooling system specific tool like the uview thing?

BostonDuce

You need this:

http://www.amazon.com/UView-550000-A.../dp/B0002SRH5G


Works as advertised.

BD

Renn 951

That seems a smart thing to do as long as the engine is out anyway.

Land Jet

I went to the shop to check on my car today. Looks like a junk yard under my car as it sits on the lift, parts everywhere.

Macster

Well, were I tracking my car or any car with this weakness I'd seriously consider having the upgrades done for safety reasons. This is part of the cost of running a car on the track, as an occasional participant or as someone who lives there.

But for those that stay on the street with their cars, I know of no hard or fast rule. This kind of preventative maintenance is up to the individual.

I looked into this a bit a while back talking it over with a tech about having these upgraded. It is an expensive task. The engine has to come out of the car to get all of them is what I recall. He said he'd never seen a Turbo in with this kind of failure.

On a related note, I have seen quite a few Cayennes in for that infamous coolant line under the manifold problem, which means ... Oh I don't know what it means. No wait, I remember: It means that if the Turbos were in the shop for this coolant pipe/fitting failure problem say as often (or half as often) as Cayennes are in for their coolant line problem I'd have my Turbo at the shop in a NY second to get this upgrade applied to my Turbo's engine.

But as I said at least in this area this failure doesn't seem to be at all common.

But this only means that if your research finds in your area the problem is more common perhaps there are regional differences (temperature related? or?) that play a role and you need to take this into account in your decision as to whether to have this done or not.

Now, I will add should I ever have any reason to have my Turbo's engine dropped (oh please dear God, no!) I'd consider having this done, provided I could afford to have it done (half-kidding) along with whatever the engine was out of the car for.

The decision to have it done or not depends upon what happens, what gets reported here and elsewhere. If the frequency of these failures goes up and it *feels* to me that the odds of this happening are 'too high' I would be more inclined to have it done.

But if the frequency of these coolant pipe/fitting failures stays low... Not likely.

Now, what is a too high a frequency of these failures? Well, one rule of thumb that I like to use is if these coolant pipe/fitting failure reports start to come in often enough that the memory of when the last one was reported was made has not faded sufficiently... that's too high a frequency. Or if I start to hear/learn from the Porsche techs they're seeing more of these failures. Then this just tips the scales more in favor of having the work done as a preventative measure.

Sincerely,

Macster.

Renn 951

Macster:

Thanks for the thoughtful response! As a Cayenne owner I've been very much aware of their plastic cooling pipe issues, but with them it seems it's not so much a matter of "if" they will fail but "when." With 78K miles on my Cayenne I just bit the bullet a year ago and paid the dealer $1700 to replace the plastic pipes with the metal ones.

On the GT1-based engines, it seems like some of these aluminum coolant fittings fail quickly but some never seem to fail, even under endurance race conditions. And from what I was reading on the GT3 forum, a lot of those guys tracking their cars have had one fail during the warranty period, and the Porsche dealers have replaced the failed connections under warranty but left all the other "yet to fail" connections alone. That would worry me greatly if it was my car and I already had one go bad. If there is some production issue here involving specific lots of material then I would think the odds go up greatly that others will fail on the same engine.

My thinking at this point is there is no way I'm going to pull the engine just to do an "insurance" fix for a problem that may never occur, but if the engine comes out for some other reason then that would be the time to address it - just like Larry is doing. And as Larry said, doing the fix on your own engine doesn't help if the GT3 you are overtaking has one of his fittings pop out. And of course any of the other water pumpers on the track can also just pop a coolant hose at a bad time and wipe out everyone immediately behind them.

Thanks again for your thoughts; time will tell whether THIS issue becomes less a matter of "if" it will fail than "when."

Land Jet

A friend of mine with a 996TT had an insert fitting fail while driving at normal speed on the street.

No SubstiTTute

An elbow fitting ( 90 degree elbow on lower right manifold in your pic) pulled out of the manifold while I was on the interstate in my 02 996TT at 35k miles 4 years ago. Gave it some throttle and boom. Created a huge cloud of white smoke and coolant was sprayed all over the back of the car. Car was under CPO at the time, but the repair was not covered because it was not a listed component on the CPO warranty brochure. $1200 to fix back then.

cannon1000

I just went through this - mine was driver's side.

1. Replace only the bad one.

2. Only if needed - they can inspect when the remove the bad one..then order everything they need afterwards or they may have in stock.

3. YES. Porsche Coolant (3 gallons) mixed with Distilled Water (3 Gal)
I had my system flushed - then refilled. I had no idea if my green stuff was Porsche coolant or aftermarket....all gone now.

4. I got as far as you did...did not want to deal with all the old coolant and disposal nor waste money on a proper coolant bleeding tool http://uview.com/ProductDetail.php?PartNumber=550500 ...I took it to the mechanic...and GLAD I DID!!!!!!!!!!!!! It is a pain in the *** and some unexpected problems occurred. You need the Snap on Radkit to power bleed the system. It’s a nightmare getting rid of all the air.

5. PORSCHE OEM. PorscheOEMparts.com has good prices. But it can be tricky identifying the correct part numbers on everything you will need.

Other advise that we learned the hard way. THe porsche OEM radiators are just slightly different than stock. SAFETY WIRE the vent tube to overflow tank ! Mine blew twice forcing us to go back in twice and fix, refill, rebleed!!!

Since your in there - safety wire all the new hoses/connections!

Seriously, take it to the dealer or a good Porsche Independent. It is a total pain in the *** to flush and bleed. They have all the gadgets to do it better and quicker - and are liable if something f's up.