Yellow Oil Leak

My 2000 996 is leaking a yellow fluid at the far rear corner of the vehicle (driver's side). The fluid looks like it could be coming from the area of engine mount, but I can't see or feel the source. The fluid is a clear yellow oil. After a recent drive, a couple of drops ended up on the garage floor, just above the exhaust tip (there is also some visible fluid on the exhaust tip and heat shield). The exterior of the water pump and coolant tank are dry, so I don't believe either is leaking. I've only owned the car for 6 years, and as far as I know, the engine mounts are original (I have the telltale gap between the exhaust tips and body > .75"). Does anyone know the color of the fluid inside the engine mounts? If it's yellow, it would help me confirm that the engine mount is the source. Otherwise, I'll start removing components for better access to see if I can locate the leak. Thanks! Adrian

Please post pictures if possible.

Motor mount oil/fluid is very-very stinky. FYI.

What color is your radiator cooling water mix?

Would this be related to this? https://rennlist.com/forums/996-foru...-mufflers.html

Wow, I cannot believe this. My car just started leaking this same fluid at the same spot as yours. I mean, like, today it started doing this. I believe (but haven�t investigated it yet) that it�s coolant. It smells like coolant and it�s clearish, maybe a hint of yellow or pink.

The coolant reservoir is notorious for developing leaks. It is typically difficult to figure out where the leak originates when looking up from underneath. If you are lucky, it is just the cap on the reservoir. The cap has been updated over the years and the latest version part number ends in 04. There are multiple threads on these issues.

Removed the snorkel White spot looks like coolant. The clamp is damp and white. The other side of the clamp is also damp and whitish From under the car, looks like greasy oil, but smells like coolant.

^* I got lucky and could see where the coolant is leaking from. It�s a 1�+ pipe (next to the 3-way pipe). It looks like an easy fix, but not looking forward to a messy and expensive job of replacing the fluid. I could save the fluid, but I have no idea how old it is, so I probably have to replace it.

The new Porsche coolant is hot pink and has been for awhile, so yours is probably pretty old.

Mike: I have the special tool to get the clamps on/off and have the vacuum system to fill the coolant system, makes it a breeze. I bought the Pentosin coolant from NAPA it's the same stuff as the factory. You are welcome to use the tools or even come over and do it in my garage if I can find time, the deck is coming along!

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See if the yellow stuff mixes with water, if so its coolant. If not oil.

it's probably just coolant that got mixed up with oily engine bay grime

I had that plastic "T" crack on me. I got the section for around $30 from pelican. Not too hard to replace once you move the smog blower. Getting the host off the expansion tank is a hassle as it is hard to get the hose clamp off with the tight clearance. But nothing too hard to tackle.

One of the best tools in my toolbox

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Thanks Paul! I�ll order the parts once I get in there a little closer and try to confirm exactly which hose is leaking. I agree, I know the Porsche coolant is the �safest� to use when I�m doubt about which coolant should be used, but any top quality coolant that meets specifications should work. I�m sure the Porsche coolant is just a rebranded coolant anyway.

I also used that clamp tool with the cable. You are not getting at that hose clamp with the plier type without the cable.

I�ve also heard that OEM-style clamps are the best and to avoid the screw-type clamps because they put pressure near the clamp and everntual cause leaks or break any plastic near that joint.

Agreed. Plus the screw clamps become loose as the hose rubber compresses over time. The spring clamps just keep steady clamp pressure. Found this out on my Hyundai when changing a t-stat. I made sure I have plenty of the spring clamps on hand.

So I was wrong about where the leak is coming from. It�s actually coming from what looks like a T right on top of the engine in the best possible place it can be. What hose is this?

I have replace that hose before. Pelican has it. Part #: 996-106-851-03-M100

The coolant line from that nipple goes to the AOS.

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The hose pic you posted looks a lot thicker than the one on my car.

There are two different type hoses that go there depending on model year, so make sure you get the right one. This is the one that is for my 99 C2

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$80.00 at NAPA

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This is the one that's leaking. This hose leads directly to the bottom of the reservoir, correct? Then it has a T splitter and continues onto another T splitter before expanding to a larger pipe that connects to the bottom of the engine (presumably the water pump)? This is the part number I think it is: Part #: 996-106-850-05-M100

For a 99 C2 that is correct. Part 18 here http://www.autoatlanta.com/porsche-p...section=105-05

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Adrian, did you ever find out what the source of the leak was? Sorry for taking over your thread with my own coolant leak issue.

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So I go to swap hoses today, and this one doesn�t fit. Turns out that Porsche changed a lot of hoses for these cars over the years. The part that came off the car is 996-106-250-54-2, and has been superseded by 996-106-850-05-M100, which also requires 996-106-243-54-M100. The original hose mates to a rigid coolant line where the replacement has a much longer rubber piece for mating. So the new rigid coolant that will be delivered hopefully tomorrow will be actually shorter. This applies to early 996 cars, which differs from later 996s. Mine has a born date of January 1999. Cars that use the 06-M100 replacement hose has a completely different dependent fitting that does apply to my car. Whew, complicated....

Sorry for the slow reply, but posting this note to close out my original post. What started out as a few drops on the garage floor, eventually turned into a small puddle. It turned out to be the typical coolant reservoir leaking. My coolant mixture is yellow. When it was on the garage floor, it felt so oily that I didn't originally think it was the coolant. Anyway, I finally got around to fixing this. I did lots of searches and found a lot of good advice. I did the standard steps: remove air box; remove air pump; disconnect all hoses to reservoir; disconnect two fuel hoses at the fuel rail (making sure that I "backed up" the fitting when loosening the nut); and did a partial engine drop (I loosened engine retaining nuts at end of engine mounts to the end of the screws, but didn't take them off completely, which gave me enough room to get the tank out). I'm in the process of ordering a new tank (man, tanks for MY 2000 are expensive!). Hopefully it will all go back together smoothly. Thanks for the input to everyone. Adrian

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A FB member just confirmed fitment of a .2 tank on a .1...