Advice on 2013 GTS (958) coolant leak
 

Hi all, I would really appreciate any advice you can offer here! Car is a 2013 Cayenne GTS (958).

Situation: Two days ago had a massive coolant leak after a bit of hard driving in hot weather. Luckily the flood came just as I was pulling into my driveway. I put it on stands and removed under panels, poured in 2 cups of 50:50 Zerex G40:Distilled water and about 2 cups flooded straight out between the engine and fire wall, on the drivers side.

Thoughts?

I know the prior model years had problems with the plastic pipes in the V, the plastic Ts and the coolant manifold fitting. Which of these were corrected by model year 2013 and which do I need to worry about? I'd like to DIY if possible and save the $3-5k the dealership would charge to pull the engine.

Thanks in advance for any help you can offer!!

If it's leaking out without the system being pressurized then it should be pretty easy to locate. Also, once it has stopped dripping check the level in the overflow tank and if there's any left that will indicate the height of the leak.

Thanks Tom, leak is when non-pressurized. Overflow tank is empty. Cannot see where the flow is coming from the top without taking off the intake manifold and cannot see it from the bottom as the transmission is in the way. Any advice on how to spot the location of the leak other than those?

If it leaks when non pressurized you probably will be able to fill the overflow tank with plain water and either use a phone/camera or just feel around for it.


You sure it's coming out from behind the engine area? Could the overflow tank or one of the lines from it cracked?

Thanks, positive it's behind the engine. Tough to even get a hand back there with the intake manifold on.

Does anyone know specifically if the 3 primary leak spots from the prior generation were fixed by 2013? (i.e., plastic pipes in the V, the plastic Ts and the coolant manifold fitting) Would be great to know if any of those could be ruled our, or in :-) Removing that manifold is quite the job.

Thanks!!

Last thing to try would be one of the endoscopes that work with a phone. I've got one and it can get into small spaces and allow you to locate items that have been dropped. Should also work on finding a leak.

Sounds like the glued in fitting on the coolant bridge between the heads has let go. People have fixed this without engine removal. A dealer will want to remove the engine most likely. People have threaded the housing and put in a custom metal fitting, other people have drilled and taped the housing to add a set screw to hold the pipe in position, and reglued it in place. I suspect JBWeld might work if you can get in to give it a good cleaning before using it.

The HPFP has to be removed to access this fitting no matter what. There are more threads about this here and on RennList.

Thanks for the response. To close the loop here, it was the fitting on the back of the water distributor that let go. I have the car up on race ramps, got the bottom panels off and can reach the fitting by threading my arm up on the left side of the bell casing above the driver side exhaust. I confirmed it with an endoscope, but it was pretty obvious the fitting let go as it was completely out and obvious by feel after seeing pictures of others.

However, I believe I can fix this w/o removing the HPFP. I will use a remote operated hose clamp clamp to take the fitting from the S hose. Clean the housing and inside of the distributor. Then reapply the Loctite 638 (which has been reformulated and should maintain seal). Then after a couple days, remount the hose and test the pressure of the coolant system using a pressure tester. Let me know what I'm missing, because it feels like after diagnosis it is actually a pretty straightforward fix.

Happy to do a write up if it'd be helpful!

Be great if you can - and write it up. I would tend to use JBWeld just because I don't trust the Henkle (Loctite) adhesive - it's failed miserably in almost every application it was used on (ask 968 owners and early Boxster owners).. JBWeld isn't coming apart once cured. I suspect part of the allure of the 638 was it could be applied with automated equipment, harder to do that with an epoxy that requires mixing.

I surmise Porsche doesn't trust it either since all the fitting that used to use it are now bolted together fittings with O rings or other sealants used.

BTW - interesting Loctite product guide: http://hybris.cms.henkel.com/medias/...t-Selector.pdf - 171 pages..

Just posted a write up on my fix. So far so good! And only cost me some patience and $150. Will link here once it's been mod reviewed.