Have a 2013 958 S with 119K and had the Y hose (under intake), water pump, thermostat and belt changed about 10 months ago. The Y hose was changed by an Indy and received the car back with low coolant after driving 50 miles so I guess it needed a burp. When the temperature dropped I noticed smoke from the rear tailpipe and didn't pay to much attention thinking its condensation. Never got thick smoke just a light stream until car was at full temp and after 4 months had to pour in 1/2 gallon of antifreeze because low coolant sign flashed. I took it back to the indy and he now suspects the engine is burning antifreeze since no obvious signs of coolant on undercarriage nor my driveway. I suspect the Y hose wasn't installed correctly and Indy is refuting my theory.

Any kind knowledge soul have any input to possible problems. Worth noting on idle the temperature is starting to rise faster than usual again implying a leak somewhere. Car drives fine otherwise.

Also looking for a good indy preferably in central NJ

 

I went through a similar scenario. Replaced all the usual suspects but still had a very slow loss of coolant with no signs of a leak. There was also a faint smell of coolant after driving. A pressure test did not reveal any leaks. Since leaky coolant caps are fairly common on some of the other models I decided to replace the coolant tank cap. This fixed the issue, no coolant smell or loss since then!

 

Expansion tank or cap would be my guess. It does sound like you might need to find another Indy as the car should never leave being not bled properly. Who know what other steps got missed. Its almost unheard of head gaskets going on the V8 or V6tt engines

 

Check your expansion tank o-rings. They are known to leak and your incompetent mechanic, I kid I kid, wont' see it when searching around the engine (area he worked on) for it. The way to coolant seeps out and down the side of the vehicle pretty much leaves no white witness stains.

 

Thanks for the advice. My cap in on the way! Did you have white smoke from the exhaust at startup?

 

No, I did not have excessive white smoke on startup. Some smoke is normal.

 

One other place that you may have to investigate is the sealing rings that are between the thermostat housing and the heads. If you have coolant dripping down where the bell housing meets the transmission and it’s NOT the Y-pipe vent that’s leaking, chances are the seals may be the culprit.

Start with the expansion tank cap and perhaps even the o-rings for the hose that connects to the expansion tank first. Coming from my BMW experiences, coolant expansion tanks get changed every 60K or if I purchased a new to me car, it gets one right away.