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2011 Porsche Cayenne S driver side coolant smell/leak
I bought this 958 Cayenne to scratch my itch for a very cool project car. It has 99,000 miles, clean car fax nice paint, great interior, makes great sounds! Checks all my boxes for an affordable project car. I have replaced the battery, plugs, coils, oil, trans fluid, transfer case fluid, wheels, tires, everything I can, to put the vehicle back to original. Using all porsche parts from many dealerships across the country. Suncoast, Gaudin, and my home dealership in Jackson, MS. I entered this project with eyes wide open. I will evertually put the same amount of money into the vehicle that I bought it for. I am looking forward to rebuilding the transfer case, transmission and hopefully dropping the engine and doing a complete refresh. However.... This damn coolant leak! For one thing was very hard to find. I could smell it after driving the car coming from the front of the vehicle. No drops of coolant underneath, only the smell. I bought a endoscope and checked all behind the engine, in the V of the engine, front of the engine etc. All areas dry, but still the smell. I am losing a small anount of coolant. Not enough to get excited about though.
I read through many posts on Rennlist, YouTube etc but nothing I found online helped. I finally bought a coolant pressure testing kit. Pressurized to about 10 lbs and let it sit. Finally! Drips right behind the drivers front tire! However, it was not from the engine. It was dripping from behind the wheel arch protector. I pulled that back and founf the leak. It is coming from a coolant line that enters the firewall vertically. I will include the pics I took just now. I need to find out what these coolant lines go to. Are they the heater core lines? Has anyone had experience with this particular issue? The leak seems to come from the metal joint, not from the rubber hose where the line enters the firewall. Any assistance or guidance will be appreciated! Taken pointing at the leak. Drivers front wheel removed You can see it has been leaking a small amount for quiet a while. Close up of where the coolant lines enter the firewall. I think this is the firewall. The camera angle is from directlt below the leak. From this angle, you can see I pulled the rubber hose off. Much corrosion where the hose connects to the 90 degree pipe. The leak seems to be coming from where the metal elbow comes out of the firewall.
Your clogged cowl drain has allowed a constant dribble of water and crud(minerals) to corrode that pipe.
Remove those cowl drain pieces, clean out the debris, and polish up that hose fitting and put it back together and it should be fine and not leak anymore.
Garrett, he also smells coolant. Groovy, those look to be your heater core hoses. You just may need a new heater core and I it may be a dash out situation. I can't find a writeup on it so I could be wrong.
Also do what Garrett said and clean that water reed valve out. It's circled in red. There is also one on the passenger side and it's' probably in the same condition. If you don't summertime will have you getting water spilled on your leg when you hit the turns.
Last edited by RAudi Driver; 02-24-2024 at 12:33 PM.
No, he just needs to fix the clogged drain, and then spruce up that pipe so it seals. The leak at that pipe is likely what he was smelling coolant from.
If you want a new pipe because you can't get the old pipe shined up nice, it's 958 572 911 02 and will be a bear to get at since you'll be undoing the entire false firewall (not the dash).
It's easy to see how and why this happened: you've had a swimming pool in the cowl, and it has been slowly dripping down this pipe from around its cowl seal, causing it to corrode over time. If you look at the area above it, you can see the corrosion and leakage.
No, he just needs to fix the clogged drain, and then spruce up that pipe so it seals. The leak at that pipe is likely what he was smelling coolant from.
If you want a new pipe because you can't get the old pipe shined up nice, it's 958 572 911 02 and will be a bear to get at since you'll be undoing the entire false firewall (not the dash).
It's easy to see how and why this happened: you've had a swimming pool in the cowl, and it has been slowly dripping down this pipe from around its cowl seal, causing it to corrode over time. If you look at the area above it, you can see the corrosion and leakage.
You just me be correct as if his heater core was gone he'd be in a steam bath. You're saying the coolant is coming from his pipes being corroded?
I am going to clean out the cowl drain... didnt know what that was to be honest. Polish up the metal pipe, clean the hose, reconnect and see what happens. I did lose about 1/2 a gallon of coolant when I removed the rubber coolant hose. Refill coolant and start it up!
End issue has been resolved 95%. I cleaned off the heater core metal lines and rubber hoses. Refit the hoses and no more leaks! Now the lower rubber lines has a very small almost wispy leak. I ordered new parts to replace all that I could in this area. No more coolant smell!
I appreciate the help very much! I have not posted in years. Now that I have a project car, it is nice to know I can get some assistance and possibly assist someone else along the way.
Thanks again!!!!!!!! The blue mark up are the hoses I will replace. I cleaned the corrosion from the metal. No more leaks!