Soooo..every once in a while I'll get a whif of coolant smell (which I hate btw!) and so it gets me worrying about, well, everything. Last night I smelled it a bit, but it doesn't leak..anywhere, no residual running off that I can see at all, while sitting or running and I've watched it while hot for several minutes. I know the dealer stated they fixed a leak while replacing a tranny seal, I wonder if I am just smelling that or if it has a small leak somewhere that's just not hitting the ground and evaporating before it does. I wonder if something on the back of the engine is leaking...And ideas guys? Thanks.

 

How's your coolant level? Have you had to add any? Have you had your coolant pipes replaced yet?

 

Realize on the Cayenne there is an undertray that can hold a lot of liquid. This may be the beginning stages of your coolant pipes cracking where it only leaks under pressure. Unless it is a lot of coolant you will only smell it and the tray will hold it rather than it being on the ground. I would recommend a pressure test of your coolant system by the dealer to be sure.

David

 

I looked through the service records and saw the pipes had been replaced....And I don't smell any fluid from the top of the motor. The coolant looks to be at the same level. I'll do some more hunting around and see what I can find. I'll have the system pressure tested when I take it in next week. Thanks.

 

Has your water pump been replaced yet? I've heard that a failing water pump can leak, and this may be the cause.

 

If you smell coolant, it IS leaking somewhere.
Does the smell get stronger when you run the fan for your AC/Heater/Defrost; or do you smell it the same all the time? My first two points of interest would be the water pump and heater core primarily; along with other signs of hose chafing or damage where it might be leaking. Check the front radiators for trace seepage.

How long/how many miles has it been since it's had a thermostat change?

Check your radiator cap, too. Those things are cheap maintenance items in light of the price of damage if something goes bad- like you having a mass coolant dump, or the thermostat sticks shut.

 

While the thermostat isn't horribly expensive, it sounds as if you're not familiar with where it's located.

Look for a thread on replacing the coolant pipes. About as deep into the top of the engine cooling system as you can get - there's the thermostat. A MAJOR job to replace, and not what I'd call a maintenance item unless you want to spend about $1,200 on labor to replace it.

I would look at the coolant cap, and the coolant reservoir (they've been known to crack and leak.) Both of those are cheap/easy replacements.

The heater core will smell up the inside of the car, it usually won't be detectable outside the car.

FWIW - It isn't uncommon to get a tiny wiff of coolant smell around the radiator cap, it does vent when the pressure in the system reaches the cap pressure relief limit. The tiny bit of coolant that escapes (primarily as steam) can condense and cause a dampness in the valley under the cap. That's enough to give a very slight coolant smell. Mine has been like that for the past 15,000 miles (and I did replace the coolant pipes - which weren't leaking), and the coolant level has never dropped. I find the smell is worse if I fill the reservoir to the FULL line when it's cold. Midway up the fill indicator seems to be where it is happiest - it stays right at the same level, day after day, week after week, mile after mile.

 

So my 04 CTT has had a coolant smell all summer but no visible leak. I have been watching the level weekly and it seemed to be fine until today. I had the engine running while i ran back inside the house quickly. When i came back I found a little puddle on the ground. It is just behind the driver side front wheel. Any ideas??

 

^^^Sorry to hear that man!

As for your issues...could be the coolant pipes under the intake manifold or I have heard of a plastic T on the back of the engine that is prone to failing because it's crappy plastic (I was thinking that this may be my issue as well). But I have not seen any leaks at all..just the occasional smell of coolant. I'm in the same group of thinking that if you can smell it..there's a leak somewhere..but I'm not 100% sure on the Cayennes (only owned mine for a couple months now). But if other owners like deilenberger smell it occasionally as well, and it can stem from the reservoir itself or cap/pressure, etc., then maybe there's not a real issue and it's normal. I'll keep looking either way and keep my eye on it.

On another note...I really can't believe that Porsche would manufacture these engines with crappy plastic parts for coolant flow, etc. Hearing all the issues with the coolant system on the Cayenne makes me angry!. Amazing to me really. (ok done ranting now)

 

It's obvious you haven't owned a modern BMW (like from the mid 90's up..) BMW uses biodegradable plastics on the cooling system. SWMBO's 5-touring sprung a tiny leak in the plastic radiator side tank.. right in the middle of the plastic. Some JB Weld stopped it for now until I get around to doing the radiator, coolant reservoir, hoses and probably a thermostat+housing just for good measure. It's had two coolant reservoirs so far (about 101k miles on it..)

Luckily, the BMW isn't one of the models that had the self-destructing cooling pump impeller (hey - worked good on the test stand..!) They went from a metal impeller to a molded plastic one, back to a metal one (stamped this time) now back to a resin one. Shows they aren't gonna give up on plastic real soon. I replaced the pump with a metal impeller one.

 

There is a rain drain somewhere right behind the drivers side front wheel. Has it rained recently? Or were you running the windshield wipers? The coolant is pretty distinctive, it's lots thicker then water (I seem to recall green in color, or is it red? I think it's red..)

Of course if you haven't had the coolant pipes done, it could certainly be those.. (I'd expect the puddle to form under the front of the transmission though..)

 

LOL, no I haven't..

So are you saying that Cayenne's have plastic impellers in the water pump or are you talking about bmw? Good info. thanks.

 

My coolant pipes have been replaced and i recently found a very small leak coming from my water pump when i did a pressure test. I was also getting a whiff of coolant every now and then. I took it to my mechanic and he suggested using a $5 coolant liquid seal that you can buy from any kragen, pep boys, etc...

I poured it into my coolant reservoir and 10 minutes later VIOALA! the leak has stopped and all is well!

 

I am 100% sure it was coolant. Now as the puddle in my garage grows the more mad I am!

 

Dunno about Porsche (but it wouldn't surprise me..) The ones I was talking about are BMWs..

And hey - coolant pipes are nothing compared to the "Profile Gasket" fiasco BMW had with the 90's 318i - where part of the engine block erroded away, and the gasket sealing the system blew out. It always happened just out of warranty. BMW's official fix was JB Weld on the block to build it back up, and a Dremel tool job to shape it.. which did work (required head removal to do) - I know ones that were fixed that way 150,000 miles ago and they're still running leak free.

JB Weld is good stuff..