9oneone

After getting my first Porsche, my 964, a few weeks ago, I've finally gotten her all sorted out and am now in the mountains for the weekend...and having a blast driving her!

Strange question for the forum: When driving down (relatively steep) hills in 2nd doing 20,30,40 mph, I'm using the engine to keep speeds down and have power on tap for curves. Strangely though, there seems to be a burning smell coming from the engine--not sure if it's oil, some sort of exhaust build up...not sure. Any ideas what this could be? After the downhills disappear, so does the smell.

PS. My oil leaks are minimal and sorted out and everything seems to be fine--oil level, pressure, temps, etc.

greg1990964

My car is similar to your with no real big leaks. A little on the engine case but not enough to even drip in garage. I get same smell after driving it really hard. have to get near engine vent to even smell it though. My guess is it is just oil burning off of cases and such.

s4magman

My guess is that you have not yet gotten used to the wonderful aroma of an aircooled Porsche.

9oneone

Ah yes, I am loving the aroma...just on the downhill there was more of a burning then aroma.

Maybe I'm overly worried because my alternator got fried on one of my first drives after getting her home and sorted! (+ wire was not properly insulated and was touching alternator housing)

greg1990964

Yeah , I meant to say that also, it is just the 911 smell. It's perfume..

Makmov

Yeah, some oil burning smell is normal and with the windows open at slow speeds it does like to get sucked in to the cabin.

an electrical fire smell is NOT normal.

Lemass Automotive

Or there is a split in your heating system and it's coming through the internal vents on your dash?

Makmov

yeah if you get stink all the time and its bad check all the heater hoses in back underside.

darth

It may be worn valve guides causing excessive oil to enter the cumbustion chamber and smoke by downhill throttle off/on action. In turn, smoke enters the ventilation system via. the main engine fan. A good test to do (i.e. for worn valve guides) while coasting at highway speeds with throttle off, then jabbing the throttle open/closed quickly and observing the exhaust (i.e visible out the rear view mirror or by someone following you) for a puff of smoke out the exhaust?

9oneone

Thanks all. I will check the test Darth suggested and when possible look at heater hoses.

I am still trying to figure out what the "normal" smell should be. When I drove her home for 6 hours after buying her a couple of weeks ago when the windows were up and the AC on, there was minimal aroma. This weekend saw windows down and sunroof open the whole time. Could it just be the nature of having everything open that I can smell the engine more? I hope my questioning doesn't seem silly--just new to 964 ownership!

9oneone

OK, so I relinquished the steering wheel of the new 964 and followed behind in my other car. I had the driver coast in 5th, with short throttle bursts. No excessive exhaust or smoke from the car, so that's good. I did notice though, that following behind my 964, I could smell the exhaust more than I can when following other cars. As an air cooled newbie, is this normal? I assume it is, but thought I'd check with you guys. Thanks!