Coolant Leak on Right Rear (not near water pump)

Looking for advise. In April I replavced my thermostat and water pump because of a small leak around the water pump pully. I replaced the coolant with Porsche red coolant and have been keeping an eye on it ever since. No issue or loss of fluid for three months and 3,000 miles until this week. Yesterday I noticed a small puddle of coolant under the engine. On further examination it was comming from the right side of the engine - not the left side where the new water pump/thermostat were mounted (See Picture). I can see that both sides of the hose are damp, but I also see coolant around the housing. What is the best approach to find the leak? The hose and clamp appear solid. I checked the fluid level this morning and it was an inch below Min so I added about a quart and filled it to Max. Thanks!

I would start by cleaning that up with some soap and water, replace both hose clamps with some quality stainless steel worm type hose clamps. The spring clamps look all used up. You can remove those by very carefully using a Dremel with a cutting wheel to cut the clamps in two places and prying it off with a screwdriver. You have to be very careful that you don't cut into the hose, just cut into the spring hose clamps enough to create a cut not all the way through but weak enough to break it with a screwdriver. That way you don't have to drain your coolant, remove the hose, replace the clamps, then refill and remove air bubbles. After that, and once it is cleaned up, drive and check again.

If that hose can be pinched easy it needs replaced. Coolant hoses on these cars are known to bust/leak. That hose is probably 30 bucks or so from Porsche. It's not one of the more expensive ones. I spent 500 on new hoses on mine and that wasn't even for every hose. Just the ones in the engine compartment. It appears that your hose is wet from top to bottom of the clamp.

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I would not recommend using worm clamps on coolant fittings. The reason OEMs use the spring clamps is because they distribute pressure evenly. When you use a worm type clamp there is more pressure just below the screw, and the heating/cooling cycles can eventually cause a crack under that point (obviously this is more of an issue for places that use a rubber hose against a plastic fitting). Just get a new OEM hose with spring clamps and it should last you another 10 years.

Update: I had to drive the car today while my SUV was being serviced. I drove 50 mile and it did slowly leak all day (only about a quart). When I got home I got it up on jack stands (I love these Jack Point jackstands!). Since it was dripping I was able to find the source. I have two pictures. One from above with the air box removed and the second from underneath the car just above the hose from my picture this morning. You can see the drip from the bottom of the large pipe. No visible evidence of anything from above. This pipe looks oddly attached with some clamp mechanism on the outside of the housing (possibly). Doing some research on that pipe/fitting now, but wanted to update this thread.

I'm going to try to get the replacement hose from the Porsche dealer today. Anyone know how to remove this wire clamp and secure the new hose? It appears that both ends of this hose go into a metal sleeve with a metal clamp that holds it in. I haven't seen anything like this before and don't want to damage anything when I replace the hose. I'm hoping to replace it and refill the coolant tonight. Thanks!

The hose has a metal end with an "O"ring. It is held in by the wire clip. Pull the clip and "wiggle" the hose out. You might want to spray it with WD40 or... to get it moving.

Thanks. I found the part number 997.106.831.03. It's out of stock at both dealers in my area so I have one being shipped to me. I'm going to pull the leaking end and clean/inspect it to see if it will stop leaking until I replace it next week.

Maybe just a dried out o-ring or the clamp lost it's strength.

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I took it apart over the weekend. The clamp seems tight. I noticed a warn area on the o-ring (didn't take a pick). It was a little flat in one spot and I assumed that May be the culprit. I cleaned it up and put it back together, drove it around for a joyride, and it was leaking when I pulled back into the garage. It's a $32 replacement hose and I can swap it out in 15 minutes. I hope the part arrives before the weekend.

Someone has updated that housing and hose to the 997 version. The 996 parts are NLA most places. I updated mine as well while I had my engine out. Any info as to why yours was updated and by who? My post here explains it. http://www.renntech.org/forums/topic...ngine-was-out/

I have no maintenance history other than the prior owner saying the clutch was replaced at 46,000 miles. I bought it with 50,000 miles December 2012. Everything looks original stock. It has a July 2004 build date on the VIN plate. Is it possible they switched to the 997 flange during 2004?

I replaced the hose today. I was fairly quick and easy, but I was very careful with the pin/clamp on the rear fitting (above the wheel well). That clamp was tight and if it popped off things could have gotten interesting...... The picture below is a section of the old gasket from the end that leaked. This was the only area of wear I could see on either end of the hose. The new hose's gaskets look perfect and the installation was a breeze. Wow a $32 fix!

Thanks for this thread! I have the exact same issue. I had done a search here before diagnosing this past Saturday, and saw this thread. When I got under the car and looked up there, it was like looking at your photos. My theory is that I may have strained this hose a few thousand miles ago, when I did a partial engine drop to facilitate the AOS replacement. Called my parts guy, and he confirmed that the old 996.106.831.01 hose has superceded to the 997 number, along with the updated hose fitting piece. For anyone running into this issue in the future, you'll need these three parts: 997.106.831.03 - superceded hose 997.106.216.00 - 'connection piece' per PET or hose fitting 996.106.321.50 - gasket

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Glad you found the post useful. I don't know when Porsche changed the housing to the 997 part (997.106.216.00) but I have see two other 2004 996s and they both had this updated connection piece. In my case all I needed was the hose.

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I got this job done on Saturday - it was pretty easy. Another data point: my car also had the updated 997 part numbers installed. I am 99.9% certain this hose has never been replaced. My car is a very late production C4S - model year 2005. A quick google search did not turn up any info on '05 C4S production numbers, but it would have to be one of the last few hundred M96 motors made.

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Can u just replace the o ring?

Not that I'm aware of. There isn't a part number for it.

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do you remember how much coolant came out when you pulled this hose?

Not a lot - if I remember correctly. but it's been a while now.....

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You don�t need a Porsche part number. Just measure it and replace it with one from a good parts supplier. Mcmaster Carr is a good source for things like o-rings.

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Have you done this with this part? I haven�t held it yet and don�t even know if the oring is even removable

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It's just an O-ring, it'll come off.

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Hi, Thanks a lot. It looks happened to me today. I googled it and found your post. It helped a lot , cause I could not find out the leaking point. I have a 996.106.831.01 in stock and was lucky if it is the case. BTW Is the fitting of 996.106.831.01 different from the 997 part ? Need antifreeze prepared for the replacement ? Regards.

After fully degreasing my engine it seems my 996.2 is leaking from the same point on the coolant hose. However mine is leaking oil and not coolant! Surely this can't be right?